EXTANT SEED PLANTS
Plant woody, evergreen; nicotinic acid metabolised to trigonelline; vascular cambium + [xylem differentiating internally, phloem externally]; stem xylem endarch, root xylem exarch; leaves with gaps, spiral, simple, buds axillary, prophylls [including bracteoles] two, lateral; true pollen +, mono[ana]sulcate, pollen exine and intine homogeneous, endexine lamellate, ovules unitegmic, crassinucellate; male gametophyte development exosporic, with two gametes, gametes with cell walls; seeds large, embryo straight, white, cotyledons 2; mitochondrial nad1 intron 2 present.
MAGNOLIOPHYTA
Lignans, O-methyl flavonols, dihydroflavonols, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, cyanogenesis via tyrosine pathway, lignins derived from both coniferyl and sinapyl alcohols, containing syringaldehyde [in positive Maüle reaction], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; cork cambium in root deep-seated, trichoblasts [differentiated hair-forming cells] 0, origin of epidermis with no clear pattern [probably from inner layer of cap]; stem with 3-layered tunica-corpus construction; stem cork cambium superficial; wood fibers and wood parenchyma +; circular bordered pits lacking margo and torus; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides; tracheids +; sieve tubes eunucleate, with sieve plate, companion cells from same mother cell that gave rise to the sieve tube and P proteins, plastids with starch grains alone; nodes unilacunar; stomata paracytic; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, vein endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, numbers unstable, P not differentiated, outer members not enclosing the rest of the bud, A many, development centripetal, with a single trace, introrse, filaments stout, anther ± embedded in the filament, tetrasporangiate, dithecal, with at least outer secondary parietal cells dividing, hypodermal endothecium +, cells elongated at right angles to long axis of anther, tapetum glandular, binucleate, microsporogenesis ?, pollen binucleate at dispersal, trinucleate eventually, endexine compact, tube elongated, gametes 2, with cell walls, nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, ovules marginal, anatropous, bitegmic, micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin, chalazal, female gametophyte ?4-nucleate, unipolar, style short, stigma ± decurrent, wet [secretory]; P deciduous in fruit; seed exotestal; double fertilisation +, endosperm ?diploid, cellular [first division oblique, micropylar end initially with a single large cell, chalazal end more actively dividing], copious, oily and/or proteinaceous, embryo cellular ab initio, small-minute; sympodial seedlings/young plants; Arabidopsis-type telomeres [(TTTAGGG)n]; whole genome duplication, single copy of LEAFY and RPB2 gene, knox genes extensively dupicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, duplication producing SEP3/LOFSEP gene pair.
Possible apomorphies are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear, because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied. Furthermore, details of relationships among gymnosperms will affect the level at which some of these characters are pegged.
NYMPHAEALES + AUSTROBAILEYALES + [MONOCOTS + CERATOPHYLLALES] + [CHLORANTHALES + MAGNOLIIDS + EUDICOTS]: pollen tectate-columellate, tectum reticulate.
AUSTROBAILEYALES + [MONOCOTS + CERATOPHYLLALES] + [CHLORANTHALES + MAGNOLIIDS + EUDICOTS]: ethereal oils in spherical idioblasts [lamina and P ± pellucid-punctate]; vessel elements with scalariform perforations; tension wood 0; nucellar cap + [character lost where?]; 12BP [4 amino acids] deletion in P1 gene.
[MONOCOTS + CERATOPHYLLALES] + [CHLORANTHALES + MAGNOLIIDS + EUDICOTS]: P whorled, more or less 3-merous [possible position], A whorled, carpels plicate, occlusion by congenital fusion; embryo sac monosporic [spore chalazal], bipolar, 8-nucleate; endosperm triploid.
MAGNOLIIDS + CHLORANTHALES + EUDICOTS: Benzylisoquinoline alkaloids +; roots endomycorrhizal [with vesicular-arbuscular mycorrhizae - level?].
EUDICOTS: Myricetin, delphinidin scattered, ethereal oils 0, asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; stomata anomocytic; flowers (dimerous), cyclic, P members with a single trace, A (opposite P), few, (polyandry widespread), filaments fairly slender, anthers basifixed, pollen tricolpate, G with complete postgenital fusion, style solid [?here]; seed coat?
SABIACEAE + PROTEALES + BUXALES + TROCHODENDRALES + GUNNERALES + CORE EUDICOTS: ?
BUXALES + TROCHODENDRALES + GUNNERALES + CORE EUDICOTS: Benzylisoquinoline alkaloids 0; mitochondrial rps2 gene lost.
TROCHODENDRALES + GUNNERALES + CORE EUDICOTS: mitochondrial rps11 gene lost.
GUNNERALES + CORE EUDICOTS: Ellagic and gallic acids common, cyanogenesis via phenylalanine, isoleucine or valine pathways; micropyle?; AP3 duplication [euAP3 + TM6 paralogs], PI-dB motif +, small deletion in the 18S ribosomal DNA common.
CORE EUDICOTS: Root apical meristem closed; flowers rather stereotyped: 5-merous, K and C distinct, K with 3 traces, A = 2x K [often numerous, but then often fasciculate and/or centrifugal], pollen tricolporate, (nectary disc +), G = K, [3] also common, connate, compitum + [level?], placentation axile, stigma not decurrent; endosperm nuclear; fruit loculicidal when a capsule; euAP1 gene +, duplication of RPB2 gene and a C lineage gene [into PLE and euAG paralogues].
ASTERIDS - Sympetalae redux? Back to Main Tree
Nicotinic acid metabolised to its arabinosides; (iridoids +); tension wood decidedly uncommon; C sympetalous, anthers dorsifixed?, ovules unitegmic, integument thick, endothelium +, nucellar epidermis does not persist, style single, long; seed exotestal; endosperm cellular, embryo long.
Page last updated: Sat, 05 Nov 2005 23:59:14 GMT
See the Berberidopsidales page for discussion on the relationships of the asterids, which have no firm position as yet.
The age of the stem group asterids may be ca 128 mybp, mid Early Cretaceous, the Cornales and Ericales diverging soon afterwards, and the other asterid orders all diverging over 100 mybp (K. Bremer et al. 2004); Wikström et al. (2003) suggest a crown group age of 117-107 mybp, while Anderson et al. (2005: asterids other then Cornales and Ericales not sampled) suggest figures of ca 112 mybp for the stem group, ca 109 mybp for the crown group. Iridoids, common in asterids, have been implicated in herbivore preferences, detering some and attracting others (e.g. see discussion in Plantaginaceae, Scrophulariaceae, etc.: Bowers 1988). Thus Uraniidae (moths) are found on Dipsacales, Lamiales, Gentianales - and also Daphniphyllaceae (an iridoid-containing member of Saxifragales - see Lees & Smith 1991).
In the asterids, compound leaves are relatively uncommon, and the leaflets are often not articulated and/or distinct. Taxa with stipules are also fairly uncommon, as are those with apetalous flowers and arillate seeds. Other characters probably have functional and logical linkages that also must be taken into account. Thus the presence of a tenuinucellate nucellus is linked with that of unitegmic ovules, the development of an endothelium (Kapil & Tiwari 1978), and a simple exotestal seed type (Netolitzky 1926); that of sympetalous monosymmetric flowers with epipetalous stamens, etc.
Albach et al. (2001a) discuss iridoid distribution, etc., in the asterids, while K. Bremer et al. (2001) suggest some morphological synapomorphies for groupings. Sympetalae of older studies were defined largely by their sympetalous corolla. Some families here included in the asterids seem to be polypetalous, but developmental studies like those of Erbar (1991) may show they have a ring primordium very early on (see, for example, Reidt & Leins 1994). The position of early initiation of the corolla tube on the tree is quite uncertain. Apiales + Asterales + Dipsacales have many members with such initiation (see Apiales page for further discussion), as do both Oleaceae and Rubiaceae, "basal" or almost so in their orders in asterid I group, and so do some Cornales. Sampling leaves a great deal to be desired, but the condition of early initiation could conceivably be a synapomorphy for the asterids (see Leins & Erbar 2003b for details). Note that a tube-forming hypanthium is rare in asterids, cf. rosids. In general, where many characters are to be placed on the tree depends on resolution of relationships within Ericales and Cornales, and the pattern of gain-loss of some of these features is liable to be rather complex; even the relative position of these two clades in asterids needs further support.
Ericales and Cornales in particular show much variation in the degree of sympetaly, stamen number, adnation of stamens to corolla, and in ovule morphology and anatomy; some of this variation is like that found in rosids, Dilleniales, etc. They may also have ellagic acid, which has a rather similar distribution (but cf. iridoids).
The monophyly of the asterids is well established (e.g. Olmstead et al. 1992, 1993, 2000; P. Soltis 1999); Albach et al. (1998) suggest the four main groupings recognised here. A phylogeny proposed by K. Bremer et al. (2001) is based on an analysis of 2 genes + morphology, one by Albach et al. (2001b) on four genes; relationships suggested by these studies are largely congruent. Differences are almost entirely in taxa not assigned to orders by APG (1998), although many of these may be assignable if the relationships suggested in the still provisional Bayesian analyses of Lundberg (2001b, d) hold. B. Bremer et al. (2002) provide a recent comprehensive phylogeny of the clade, although with minimal sampling within families, using three coding and three non-coding chloroplast markers. Both B. Bremer et al. (2003) and Olmstead (2000) suggest that there is strong support for Cornales being the sister to all other asterids; see also Albach et al. (2001) and Soltis et al. 2003. However, Hilu et al. (2003) reverse the positions of Cornales and Ericales, but the matK gene alone was sequenced. Note that in their study, Caiophora (Loasaceae) appears in Asterales, far separate from the other members of the family in the analysis - perhaps mistaken identity?
The distinction between the other angiosperms and the asterids partly corresponds to the distinction between the crassinucellate and tenuinucellate groups of Young and Watson (1970, based on phenetic analyses). There are also substantial differences, for example, Young and Watson included Apiaceae-Araliaceae in their crassinucellate group. Philipson (1974) further emphasized the distinction between the crassinucellate and tenuinucellate groups of Young and Watson, linking the two via Celastraceae, Grossulariaceae and Brexiaceae (here Celastrales, Saxifragales, and Crossosomatales); Theales, Primulales and Ebenales together made up a separate lineage (here part of Ericales). Later Philipson (1977) resurrected van Tieghem's (1901) names Unitegminae and Bitegminae for these two groups; integument number and nucellus condition are correlated.
CORNALES Dumortier* Back to Main Tree
Iridoids diverse, ellagic acid +, flavones 0; vessel elements with scalariform perforations; nodes 3:3; inflorescence cymose; (flowers 4-merous), C valvate, apparently free, tube formation early, A basifixed, G inferior, disc +, 1-2 apical ovules/carpel; fruit drupaceous, with germination valve(s) in the stone, K persistent.
Fossils of this small clade are datable to the Maastrichtian, ca 70 mybp (Nyssa) and Coniacian, ca 87 mybp (Takahashi et al. 2002: Hironoia); Anderson et al. (2005) suggest figures of ca 109 mybp for the stem group, 101-97 mybp for the crown group.
The strands of apotracheal parenchyma are relatively long (at least 9 cells long) in Cornaceae s.l. (inc. Curtisiaceae) when compared with some of their putative relatives (Noshiro & Baas 1998). Spirally-thickened vessels holding the two halves of transversely-torn leaves together are quite common... Teeth of Nyssaceae and Hydrangeaceae have a clear apex with a foramen, higher order laterals are involved (Hickey & Wolfe 1975). The petals may be free, but corolla tube formation, when known, is early (e.g. Reidt & Leins 1994).
For more details, see Faure (1924), Ferguson (1977: pollen), Sato (1976) and Grayer et al. (1999: saponins).
Hydrangeales were included in Cornidae-Cornanae in Takhtajan's (1997) treatment, but Loasales-Loasanae were part of Lamiidae. 11/15 of the genera of Cornaceae s.l. have been placed in monotypic families, or the family has been circumscribed very broadly, as by Mabberley (1997). Molecular studies (e.g. Xiang et al. 1993) suggest a break-up of the family; the core is here. Relationships between genera in this core are unclear, but at least some aggregation of the families they represent is in order (e.g. Albach et al. 2001b; Xiang et al. 2002); relationships in Cornales as a whole are unclear. Although Cornus is sister to Mastixiaceae in some morphological trees (Murrell 1993), it is not close in rbcL trees (Xiang et al. 1993, 1997). For the relationships of Grubbiaceae and Hydrostachyaceae, see especially Xiang (1999), Fan and Xiang (2003) and Xiang et al. (2002); the tree here is based largely on the last two papers. Note that the inclusion of Hydrostachys in analyses considerably affects topologies and support values. For other Cornales s.l., see e.g. Garryaceae (Garryales), Curtisiaceae (Solanales) and Griseliniaceae (Apiales).
This is the asterid IV group of some early phylogenetic studies.
Includes Cornaceae, Curtisiaceae, Grubbiaceae, Hydrangeaceae, Hydrostachyaceae, Loasaceae, Nyssaceae.
Synonymy: Grubbiales Doweld, Hortensiales Grisebach, Hydrangeales Nakai*, Hydrostachyales Reveal*, Loasales Bessey* - Cornanae Reveal, Loasanae Reveal* - Cornidae Reveal*
Cornaceae + Nyssaceae: (plants Al accumulators); route I secoiridoids, triterpenoid saponins +, tanniniferous; (mucilage +); hairs T-shaped, unicellular; flowers small, K notably small, pollen with complex endaperture [a pore joining two lateral thinnings parallel to the colpus], ventral carpellary bundles usu. in the carpel wall [transseptal bundles], (archesporium multicellular), style short; (endosperm also nuclear).
It is not clear that these are sister taxa, nevertheless, they do have a number of features in common.
CORNACEAE Dumortier* Back to Cornales
Trees and shrubs (stoloniferous subshrubs); flavonols, also route II decarboxylated iridoids, isoquinoline alkaloids +; (latex +); (vessel elements with simple perforations); sclereids +; petiole bundle arcuate, or D-shaped or annular (with medullary bundle); branching various; hairs (stellate), walls often with crystals; leaves opposite, bases joined by a line, spiral or 2-ranked, conduplicate(-flat) or curved (both -plicate) or involute, margins entire (lobed), 2ndary veins pinnate or subpalmate; flowers 4(-10)-merous, K connate or not, A = and opposite K (-4x, anthers long - Alangium), pollen with H-shaped endapertures, often starchy, G [1-4] (1 loculus), ovules apotropous, (tenuinucellate - red-fruited Cornus), (style long, with long arms), stigma truncate to capitate, dry; fruit 1-2-seeded, endocarp of sphaeroidal cells; testa of elongated cells, much compressed (ca 6 cells thick, vascularized - Alangium); endosperm hemicellulosic, embryo green; n = 8-11.
Cornaceae
2[list]/85: Cornus (65 spp). Scattered, not S. South America (Map: see van Steenis & van Balgooy 1966; Aubréville 1974; George 1984; Meusel et al. 1978; Hultén & Fries 1986). [Photo - Habit] [Photos - Inflorescence] [Photos - Flower] [Photos - Fruit]
* Many Cornaceae are recognisable vegetatively by their T-shaped hairs and leaves often with entire margins and actinodromous venation. The flowers are often small and aggregated into heads or other compact inflorescences; the flowers of one inflorescence open more or less together. The flowers have a small calyx, apparently free and valvate petals, an inferior ovary crowned by a disc and with 1-2 locules/carpel, and a 1-seeded drupaceous fruit.
Blue-fruited dogwoods have lost iridoids (Xiang et al. 1997). In nodes of Alangium the central vascular trace may immediately divide into three (nodes 3:5!). Mabberley (1997) describes Alangiaceae as having spiral leaves; they are often 2-ranked. In Alangium there is a very little vascular tissue in the center of the ovary, while there is considerable variation in embryo sac development in Cornus in particular (Johri et al. 1992 for references).
For information, see Horne (1914), Adams (1949: anatomy) and Eyde (e.g. 1968, 1988: flower and fruit in particular), Neubauer (1978: petiolar anatomy), Jensen et al. (1975a: iridoids), and Kubitzki (2004b: general). For relationships within Cornus, cf. Murrell (1993) and Xiang et al. (1993).
Synonymy: Alangiaceae de Candolle*
NYSSACEAE Dumortier* Back to Cornales
Trees and shrubs; route I secoiridoids +; (resin +); petiole bundles arcuate or with adaxial plate; leaves spiral (opposite), conduplicate [Nyssa], margins serrate or entire; plants andromonoecious, dioecious, etc., or flowers perfect; inflorescences various (capitate); flowers 4-5-merous; C ± imbricate, or valvate and inflexed at apex, or P 0, A 4-26 [often diplostemonous], G [5-10], (loculus and ovule 1), (styles separate); endocarp fibrous; fruits 1-5-seeded; (seed U-shaped - Mastixia), testa multiplicative, exotesta lignified; embryo long or short; n = 11, 13 [both Nyssa], 21, 22.
5/22. Mainly East Asia, also Indo-Malesia and E. North America (Map: see van Steenis & van Balgooy 1966; Matthew 1977). [Photo - Nyssa Flower] [Photo - Nyssa Fruit © H. Wilson]
Fossils of Nyssaceae fruits are widespread in the northern hemisphere, some being 3- or 4-carpellate (Eyde 1997, for details), Mastixia was especially abundant in Europe 65-70 mybp.
Davidia has flowers in capitula subtended by 2 large white bracts; it lacks a perianth and may have bitegmic ovules. Diplopanax has recently been placed in Mastixiaceae s. str. (Eyde & Quiyun 1990; cf. Xiang et al. 1997). It has five lobes on the disc opposite the corolla and a single-seeded fruit the embryo of which is C-shaped in transverse section (Ying et al. 1993).
For cytology, see He et al. (2004), for general information, see Kubitzki (2004b: as Cornaceae), for Mastixia, see Matthew (1976); embryological details are unknown for it and Diplopanax.
Synonymy: Davidiaceae H.-L. Li*, Mastixiaceae Calestani*
Hydrangeaceae + Loasaceae: similar route I secoiridoids and route II decarboxylated iridoids [e.g. deutzioside], flavonols +, ellagic acid 0; cork deep-seated; hairs tuberculate, walls calcified, with basal cell pedestals; leaves opposite, with glandular teeth (lobed); A (initiated as antesepalous triplets), (2x C-)many, placentation parietal, many tenuinucellate ovules/carpel, stigma dry; fruit septicidal (persistent placental strands +); exotestal cells variously elongated, inner walls thickened; micropylar and chalazal haustoria +; mitochondrial coxII.i3 intron 0.
The androecium of both families is very variable in development (Hufford 1990, 1998). It is possible that diplostemony is plesiomorphic, with polystemony derived. The antisepalous androecial triplets sometimes found here are also found in Rosaceae and Zygophyllaceae (Hufford 2001b, see also Ronse Decraene & Smets 1996a). The embryology of the group is poorly studied.
HYDRANGEACEAE Dumortier* Back to Cornales
Shrubs, vines, or herbs; (plants Al accumulators); kaempferol, myricetin, flavonols +, tanniniferous; (hairs stellate or branched); cork inner cortical or outer pericyclic; (vessel elements with simple perforations); true tracheids +; (stomata paracytic); leaves conduplicate or supervolute, bases joined by lines across the stem, (2ndary veins palmate); inflorescence?; flowers 4-5(-10)-merous, anthers basifixed, with basal pit, nectary vascularised, G [(2-)3-5(-12)] to inferior, arrangement variable, placentation intrusive parietal, ovules apotropous, style single or separate, stigma linear to capitate; seed winged or not; endosperm moderate; n = 13-18.
17[list]/190 - divided into two subfamilies. Warm temperate, some species in tropics. [Photo - Flower] [Photos - Collection]
1. Hydrangeoideae
Nodes also 5:5, 7(+):7(+); petiole bundles (arcuate [+ inverted bundles]) annular, often with medullary bundles; raphide sacs + (0); integument 3-5 cells across; (fruits baccate; loculicidal; opening down sides).
15/185: Philadelphus (65). Warm temperate, esp. South East Asia and North America, S. to Chile and Malesia (Map: from McClintock (1957), van Balgooy 1984).
In Hydrangea the calyx of the marginal flowers of the inflorescence is sometimes petaloid.
Inc. Philadelphaceae Martynov
For floral morphology of Hydrangeae, see Hufford (2001). The base of the endosperm is lignified.
2. Jamesioideae Hufford
Nothing obvious! Leaf buttresses prominent after leaves fall; K valvate, C free, A 10, style branches separate or almost so.
2 (Jamesia, Fendlera)/ca 5. W. North America.
* Hydrangeaceae are usually rather robust herbs or shrubs with opposite leaves that are joined by a line across the stem. The flowers have free petals that are valvate in bud and at least twice as many stamens as petals; the ovary is more or less inferior.
In a number of taxa the embryo sac more or less protrudes into the micropyle or beyond (Hufford 2004). The presence of chalazal haustoria needs confirmation.
Philadelphus shows centrifugal androecial development. In Philadelphus, Dichroa and Deutzia the four carpels alternate with the sepals, or there are three carpels with the odd member adaxial; in Hydrangea the odd carpel is abaxial, while in Broussaisia the five carpels are opposite the sepals. Fendlera has nuclear endosperm (Johri et al. 1992).
For variation in the position of the carpels when the gynoecium is bicarpellate, see Eichler (1878; also Eckert 1966), for vegetative anatomy, Watari (1939) and Gornall et al. (1998), for floral anatomy, see Bensel and Palser (1975c), for seeds, Hufford (1995, 1997) and Nemirovich-Danchenko and Lobova (1998), for iridoids, Frederiksen et al.(1999), for androecial development, Hufford (1998, 2001a), and for general information, see Hufford (2004). For relationships within the family, see Hufford (1997), Hufford et al. (2001: support for its monophyly is not overwhelming), and Soltis et al. (1995a), and for a classification of the family, see Hufford et al. (2001).
Synonymy: Hortensiaceae Berchtold & J. S. Presl, Kirengeshomaceae Nakai
LOASACEAE Jussieu* Back to Cornales
Often coarse herbs (shrubs); myricetin, tannins 0; cork inside pericycle; vessel elements with simple perforations; petiole bundles arcuate or annular, with wing bundles; trichomes glochidiate (stinging), often silicified; leaves (spiral; compound; margins lobed), 2ndary veins pinnate-palmate; flowers (4-)5(-7)-merous; K connate, C with three traces, imbricate, C-A synorganisation, C-A plate formed, filaments terete, tectum striate, G 5 (± superior), opposite K, ovules epitropous, tenuinucellate, integument very thick, style single, lobed, stigma narrow or clavate; (fruit a cypsela; spirally twisted); (testa with hypodermal layer thickened); endosperm copious to none.
14[list]/265 - five clades below. Mostly American, but also Africa and the Marquesas Islands.
1. Eucnide
(C connate), A (adnate to C), centripetal, connate basally; fruit a septicidal capsule; n = (?19-)21.
1/15. S.W. North America. [Photo - Eucnide Flower © J. Reveal]
2. Schismocarpus
A 10, filaments shorter than the anthers, G opposite C, stigma capitate.
1/1: Schismocarpus pachypus. Mexico.
Loasoideae + Mentzelioideae + Gronovioideae: G 3-5, when 3, odd member adaxial.
There are some remarkable flowers here!
3. Loasoideae
Petals cymbiform, clawed, A centripetal and centrifugal, stamens in groups opposite C, pollen ?not striate, antesepalous staminodes + [outer whorl connate, as scales, inner whorl separate, more elaborated]; n = 6.
Loasa (105). America, but also Africa (Kissenia) and the Marquesas Islands (Plakothira). [Photo - Flower] [Photo - Flower]
The calyx and corolla are shed separately. The relatively recently-described Plakothira and Kissenia may be sister to the rest of the subfamily (Hufford et al. 2003), or not part of the same clade and part of a major basal polychotomy (Weigend et al. 2004).
For a phylogeny, see Hufford et al. (2005).
Mentzelioideae + Gronovioideae: loss of C-A synorganisation.
4. Mentzelioideae
A centripetal, connate basally, (forked staminodes +); n = 7.
Mentzelia (60). [Photo - Flower © S. Wolf]. America.
The calyx and corolla are shed as a unit.
5. Gronovoioideae
(Hypanthium +), C valvate, petals with a single vascular trace, A 5, opposite K (2, three staminodes), anthers bifacial, G with 1 apical crassinucellate [Petalonyx, Gronovia] ovule, funicular obturator +; fruit a cypsela; testa none; endosperm haustoria 0.
[Photo - Gronovia Flower]. America.
In some species of Petalonyx there is postgenital fusion of the corolla, this forces the stamens outside the corolla.
Inc. Cevalliaceae Grisebach, Gronoviaceae Endlicher
* Loasaceae are usually herbs that have barbed or glochidiate silicified and sometimes stinging hairs; at least the first pair of leaves is opposite. The flowers, which usually have separate, spreading petals, numerous, radiating stamens with long filaments, and an inferior ovary, are distinctive.
Strongly supported relationships suggested by Moody and Hufford (2000), Moody et al. (2001), Hufford et al. (2003) and Hufford (2003) are Eucnide [Schismocarpus [Loasoideae [Mentzelioideae + Gronovioideae]]].
For the complexities of androecial initiation, see Hufford (1990); antepetalous stamens arise from the flanks of primordia of antisepalous stamens. Hufford (2003) describes staminode evolution in detail. Additional information is taken from Vijayaraghavan and Kaur (1967), Thompson and Ernst (1967), Weigend (1996), Hufford (1988, 1989, 1990) and especially Moody and Hufford (2000) and Weigend (2004: general).
HYDROSTACHYACEAE (Tulasne) Engler* Back to Cornales
Annual to perennial submerged herbs; primary root 0; kaempferol +, iridoids 0; vessels present, ?type; nodes ?; stomata 0; leaves in a rosette, deeply and complexly divided, surface with small enations, stipule single, intrapetiolar (two, lateral); inflorescence spicate, plants di(mon)oecious, P 0, nectary 0; staminate flowers: A 2, extrose, bisporangiate/monothecal, pollen in tetrads, inaperturate; carpellate flowers: G [2], transverse, placentation parietal, many tenuinucellate ovules/carpel, styles separate, filiform; fruit a septicidal capsule; seeds minute, exotestal, outer cell walls much thickened, mucilaginous, endosperm scanty or 0, micropylar haustorium +; n = 10-12.
Hydrostachyaceae
1[list]/20. C. and S. Africa, Madagascar (Map: from Heywood 1978).
* A submerged, rosette-forming aquatic herb with complex leaves bearing enations, stipules that are usually intrapetiolar, dense, spicate inflorescence, and rather small flowers with extrorse anthers, free styles and transverse carpels.
Another interpretation of the androecium is that is consists of one tetrasporangiate stamen. Vessels are reported (Jäger-Zürn 1998), but are not described. Hydrostachyaceae have variously been suggested as being sister to Decumaria, or close to Crassulaceae, or - perhaps - close to Podostemaceae (near Clusiaceae); Takhtajan (1997) included Hydrostachyales in Lamiidae. The embryology shows certain similarities with that of Crassulaceae, but relationships there or with Clusiaceae are not close. Members of sympetalous groups, especially Lamiales, show similarities to Hydrostachyaceae in ovary structure (apical septae) and ovule and endosperm development (Jäger-Zürn 1965; see also Leins & Erbar 1990). All in all, a position within Hydrangeaceae (but note the very long branch!) may be most likely (Xiang 1999; see also Hempel et al. 1995; Olmstead et al. 2000; Albach et al. 2001; Fan & Xiang 2001; Xiang et al. 2002); what about the mitochondrial coxII.i3 intron (Joly et al. 2001)? As Albach et al. (2001) note, few morphological characters support this position, but this is perhaps to be expected of a highly-derived aquatic...
For general information, see Erbar and Leins (2004).
Grubbiaceae + Curtisiaceae: leaves opposite, bases connected by a ridge; flowers small, one tenuinucellate ovule/carpel, style short; endosperm copious.
For characters holding these two families together, see in part Xiang et al. (2002).
GRUBBIACEAE Endlicher* Back to Cornales
Evergreen ericoid shrubs; iridoids 0?; hairs unicellular; cuticle waxes as long narrow platelets; leaf margins revolute; inflorescences axillary, capitate or cone-like; flowers also 6-merous, C 0, A 8, 12, anthers inverted, bisporangiate/monothecal, G [2], transverse, disc hairy, placentation axile at base, becoming free-central, ovule epitropous, integument "thick", style shortly 2-lobed; fruit a syncarp, seed [per fruit proper] 1, coat thin; endosperm ?type, micropylar and chalazal haustoria +; n = ?
Grubbiaceae
1[list]/3. Cape Province, South Africa (Map: from Vester 1940).
* Grubbiaceae are ericoid shrubs with capitate or cone-like inflorescences lacking radiating inflorescence bracts; its fruits are closely aggregated (cf. Bruniaceae).
The family is poorly known. There is support for a sister group relationship to Curtisiaceae (e.g. Fan & Xiang 2001); Xiang et al. (2002) suggested that the two might be combined, but they are kept separate here because they are rather different in appearance. The inversion of the anther is very comprehensive in Grubbiaceae, and for some (e.g. Fagerlind 1947b) this has suggested relationships with Ericaceae. Carlquist (1978a) found Grubbiaceae (near Asterales here) to be anatomically identical to Bruniaceae, cf. also Geissolomataceae. Are there central bundles in the ovary of Grubbiaceae?
Some information is taken from Schnizlein (1843-1870: fam. 18 - carpel orientation), Fagerlind (1948b: embryology), Dahlgren and van Wyk (1988: general) and Kubitzki (2004b: general).
Inc. Ophiraceae Arnott
CURTISIACEAE (Engler) Takhtajan* Back to Cornales
Evergreen trees; route I secoiridoids +, ?ellagic acid; ?cork; ?nodes; petiole bundle annular, with medullary strands; leaves ± flat, margins serrate; inflorescence terminal; K small, A = and opposite K, pollen with H-shaped endapertures, G [2-4], stigma 4 lobed; fruit 4-seeded; ?endosperm haustoria, embryo long; n = 13.
1/2. S. Africa. [Photo - Fruit]
Takhtajan (1997) described the hairs of the branchlets, petioles and inflorescences of Curtisia as being stellate (they are curled). The "plications" (Cullen 1978) in the young leaves are in fact only prominent veins. Curtisia is embryologically unknown, but it lacks transseptal bundles, having the "normal" central bundles.
For general information, see Kubitzki (2004b).
EXTANT SEED PLANTSPlant woody, evergreen; nicotinic acid metabolised to trigonelline; vascular cambium + [xylem differentiating internally, phloem externally]; stem xylem endarch, root xylem exarch; leaves with gaps, spiral, simple, buds axillary, prophylls [including bracteoles] two, lateral; true pollen +, mono[ana]sulcate, pollen exine and intine homogeneous, endexine lamellate, ovules unitegmic, crassinucellate; male gametophyte development exosporic, with two gametes, gametes with cell walls; seeds large, embryo straight, white, cotyledons 2; mitochondrial nad1 intron 2 present.MAGNOLIOPHYTALignans, O-methyl flavonols, dihydroflavonols, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, cyanogenesis via tyrosine pathway, lignins derived from both coniferyl and sinapyl alcohols, containing syringaldehyde [in positive Maüle reaction], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; cork cambium in root deep-seated, trichoblasts [differentiated hair-forming cells] 0, origin of epidermis with no clear pattern [probably from inner layer of cap]; stem with 3-layered tunica-corpus construction; stem cork cambium superficial; wood fibers and wood parenchyma +; circular bordered pits lacking margo and torus; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides; tracheids +; sieve tubes eunucleate, with sieve plate, companion cells from same mother cell that gave rise to the sieve tube and P proteins, plastids with starch grains alone; nodes unilacunar; stomata paracytic; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, vein endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, numbers unstable, P not differentiated, outer members not enclosing the rest of the bud, A many, development centripetal, with a single trace, introrse, filaments stout, anther ± embedded in the filament, tetrasporangiate, dithecal, with at least outer secondary parietal cells dividing, hypodermal endothecium +, cells elongated at right angles to long axis of anther, tapetum glandular, binucleate, microsporogenesis ?, pollen binucleate at dispersal, trinucleate eventually, endexine compact, tube elongated, gametes 2, with cell walls, nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, ovules marginal, anatropous, bitegmic, micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin, chalazal, female gametophyte ?4-nucleate, unipolar, style short, stigma ± decurrent, wet [secretory]; P deciduous in fruit; seed exotestal; double fertilisation +, endosperm ?diploid, cellular [first division oblique, micropylar end initially with a single large cell, chalazal end more actively dividing], copious, oily and/or proteinaceous, embryo cellular ab initio, small-minute; sympodial seedlings/young plants; Arabidopsis-type telomeres [(TTTAGGG)n]; whole genome duplication, single copy of LEAFY and RPB2 gene, knox genes extensively dupicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, duplication producing SEP3/LOFSEP gene pair.Possible apomorphies are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear, because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied. Furthermore, details of relationships among gymnosperms will affect the level at which some of these characters are pegged.NYMPHAEALES + AUSTROBAILEYALES + [MONOCOTS + CERATOPHYLLALES] + [CHLORANTHALES + MAGNOLIIDS + EUDICOTS]: pollen tectate-columellate, tectum reticulate.AUSTROBAILEYALES + [MONOCOTS + CERATOPHYLLALES] + [CHLORANTHALES + MAGNOLIIDS + EUDICOTS]: ethereal oils in spherical idioblasts [lamina and P ± pellucid-punctate]; vessel elements with scalariform perforations; tension wood 0; nucellar cap + [character lost where?]; 12BP [4 amino acids] deletion in P1 gene.[MONOCOTS + CERATOPHYLLALES] + [CHLORANTHALES + MAGNOLIIDS + EUDICOTS]: P whorled, more or less 3-merous [possible position], A whorled, carpels plicate, occlusion by congenital fusion; embryo sac monosporic [spore chalazal], bipolar, 8-nucleate; endosperm triploid.MAGNOLIIDS + CHLORANTHALES + EUDICOTS: Benzylisoquinoline alkaloids +; roots endomycorrhizal [with vesicular-arbuscular mycorrhizae - level?].EUDICOTS: Myricetin, delphinidin scattered, ethereal oils 0, asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; stomata anomocytic; flowers (dimerous), cyclic, P members with a single trace, A (opposite P), few, (polyandry widespread), filaments fairly slender, anthers basifixed, pollen tricolpate, G with complete postgenital fusion, style solid [?here]; seed coat?SABIACEAE + PROTEALES + BUXALES + TROCHODENDRALES + GUNNERALES + CORE EUDICOTS ?BUXALES + TROCHODENDRALES + GUNNERALES + CORE EUDICOTS: Benzylisoquinoline alkaloids 0; mitochondrial rps2 gene lost.TROCHODENDRALES + GUNNERALES + CORE EUDICOTS: mitochondrial rps11 gene lost.GUNNERALES + CORE EUDICOTS: Ellagic and gallic acids common, cyanogenesis via phenylalanine, isoleucine or valine pathways; micropyle?; AP3 duplication [euAP3 + TM6 paralogs], PI-dB motif +, small deletion in the 18S ribosomal DNA common.CORE EUDICOTS: Root apical meristem closed; flowers rather stereotyped: 5-merous, K and C distinct, K with 3 traces, A = 2x K [often numerous, but then often fasciculate and/or centrifugal], pollen tricolporate, (nectary disc +), G = K, [3] also common, connate, compitum + [level?], placentation axile, stigma not decurrent; endosperm nuclear; fruit loculicidal when a capsule; euAP1 gene +, duplication of RPB2 gene and a C lineage gene [into PLE and euAG paralogues].SAXIFRAGALES + VITALES + ROSIDS: Nodes 3:3; stipules +.VITALES + ROSIDS: Anthers ± dorsifixed, transition to filament narrow, connective thin.ROSIDS Back to Main TreeAnthers articulated [± dorsifixed, transition to filament narrow, connective thin]; (fruit a loculicidal capsule); embryo long, endosperm copious; chloroplast infA gene defunct, mitochondrial coxII.i3 intron 0.The age of the rosid clade has been estimated at 117-108 mybp (Wikstr&m et al. 2003); fossils assignable to rosids are ca 94 my (Crepet et al. 2004). The age of the rosids in Anderson et al. (2005) should be treated with caution, since members of both Vitales and Crossosomatales were included in their rosids - and there was also a separate Crossomatales. Butterfly caterpillars are common on members of the group, occuring about twice as frequently as might be expected going by species number alone, but the tree habit is also common in the group, and trees show a perhaps correspondingly disproportionate number of larvae... (Janz & Nylin 1998).The actual limits of the rosids - a practical matter at this stage, perhaps - are unclear. D. Soltis et al. (2003a) found 79% support for the clade, but they might also include Vitales and Saxifragales, the latter being sister to the rest of the group (e.g. P. Soltis et al. 1999: Vitales not included), albeit with weak support. See the Berberidopsidales page for further discussion on the relationships of the rosids, which have no firm position as yet.The feature of cuticle wax platelets as rosettes is scattered through this group, but is especially common in Fabaceae and is known from several Malpighiales (see Ditsch & Barthlott 1997 for details). The sepals characteristically have three traces from three gaps; in several more basal eudicot clades the outer perianth/sepals have only a single gap (von Balthazar and Endress 2002 - see also Ranunculales). Petal development is often retarded relative to that of other parts of the flower (also in Cabomba and Saruma!).Unplaced: Back to Main TreePICRAMNIACEAE Fernando & QuinnTrees; bark often very bitter; vessel elements with simple perforations; nodes 3:3; leaves spiral, pinnate, conduplicate, leaflets often ± alternate, extrafloral nectaries +; plant dioecious, inflorescence racemose, flowers 3-5(-6)-merous, small, K connate basally (free), staminate flowers: A = and opposite C, pollen?, disc, pistillode minute; carpellate flowers: staminodes [?nectariferous] +, G [2-3], 2 ovules/carpel, micropyle ?bistomal, styles recurved, pointed; endosperm ?development; n = ?2[list]/46. Neotropical.
PicramnioideaePicramnioideae EnglerQuassinoids +; ovules epitropous, apical; fruit a berry; seed coat ca 6 cells across, vascularised, unlignified, or two subepidermal layers lignified, inner layers crushed; embryo minute.1/41. S.E. USA, Central and South America, Caribbean (Map: from Pirani 1990). [Photo - Fruit]For seeds, see Picramna sellowiana (Vásquez & Jaramillo 11419) and P. latifolia (Aguilar 5020).
AlvaradoideaeAlvaradoideae Liebm.Anthraquinones +; staminate flowers: C usu. 0; carpellate flowers: staminodes opposite K, only 1 G fertile, ovules apotropous, basal; fruit a samaroid capsule; exotesta resinous, endotegmen as a resinous membrane; endosperm 0, cotyledons large.1/5. Florida, Central America, Bahama, esp. the Greater Antilles, Bolivia to Argentina (Map: from Thomas 1990). [Photo - Fruit]For some chemistry, see Villatoro et al. (1974), and for seeds, see Núñez et al. 83. * Picramniaceae are often rather small trees with spiral, compound leaves; the leaflets alternate along the rachis and the bark is bitter. The small flowers are born in a raceme, and the stamens are equal to and opposite the petals.The family is very poorly known; I have seen only Picramnia in the field. Xylem parenchyma is rather scanty to absent. Fiber tracheids dominate, but Alvaradoideae commonly have vascular tracheids (Webber 1936). Picramniaceae were placed between Rosid I, which includes Surianaceae and Irvingiaceae (ex Simaroubaceae), and Rosid II, which includes Simaroubaceae themselves, by Fernando et al. (1995), but in the past they have usually been placed within Simaroubaceae (e.g. Cronquist 1981; Takhtajan 1997).For general information, see Fernando and Quinn (1995) and for chemistry, see Hegnauer (1973, 1990, as Simaroubaceae). Rao (1970) briefly mentions the seed coat of Alvaradoa.Synonymy: Picramniales DoweldCROSSOSOMATALES Reveal Back to Main Tree?Nodes; stomata anomocytic; leaf margins toothed, stipules +, cauline; hypanthium +, with nectary [disc], G stipitate, ovules apotropous, micropyle bistomal [zig-zag], both integuments 4 or more cells across, styles free, compitum present only near stigma, stigma wet; seed testal, walls of outer layers much thickened.
Page last updated: Sat, 05 Nov 2005 23:59:14 GMTEstimates of the age of this clade are in the order of 104-97 mybp, with divergence beginning 95-91 mybp (Wikström et al. 2001).The petals usually have but a single trace. The inner integument in particular may be only three cells thick (Crossosoma, Geissoloma).A surprising group, but it is likely to be monophyletic. Relationships of some of the families included here like [[Aphloiaceae + Ixerbaceae] [Staphyleaceae [Stachyuraceae + Crossosomataceae]]] (D. Soltis et al. 1999, 2000; cf. in part Koontz and Soltis 1999) and [[[Crossosomataceae + Stachyuraceae] Staphyleaceae] Geissolomataceae] (rbcL tree in Nandi et al. 1998) have been suggested; see also Savolainen et al. (2000a). The tree here is based on these studies, and also that of Sosa and Chase (2003). Although some relationships within the group remain unclear, and Crossosomatales as a whole are not very strongly supported, the similar and distinctive seed coat anatomy of the included members is interesting. Furthermore, despite the apparently rather heterogeneous nature of Crossosomatales, Matthews and Endress (2005) emphasise the number of distinctive features of the order, even if exactly where some of these are to be placed on the tree is unclear. For instance, the funicular vascular bundle ends undivided in the chalaza in Stachyuraceae and Staphyleaceae, whereas it splits into 3-6 short bundles in the other families, although Geissolomataceae were not studied. Is a divided bundle an apomorphy for the order (or larger group), lost in the Staphlyeaceae-Stachyuraceae-Crossosomataceae clade, and so a synapomorphy for it, but then regained in Crossosomataceae? Or is its distribution to be explained by some other combination of gains and losses (the distribution of "luminous" stylar canals and loculi may be the same)? Of course, more detailed study of this character may change the question. Matthews and Endress (2005) also note that there is much more in common between Crossosomatales in the broad sense (as delimited below) than in the narrow sense (Crossosomataceae, Stachyuraceae, Staphyleaceae). Does Gumillea (ex Cunoniaceae) belong here?For the distribution of characters of floral morphology in the group, I largely follow the excellent study by Matthews and Endress (2005), which whould be consulted for more details, alternative interpretations of states, etc.Crossosomatales treeIncludes Aphloiaceae, Crossosomataceae, Geissolomataceae, Ixerbaceae, Stachyuraceae, Staphyleaceae, Strasburgeriaceae.Synonymy: Geissolomatales Reveal*, Ixerbales Doweld - Crossosmatanae DoweldStaphyleaceae + Stachyuraceae + Crossosomataceae: leaves or leaflets involute; stigma ± expanded.The age of Crossosomatales (stem group 89-83 mybp, crown group 47-40 mybp) properly refers to this clade (see Anderson et al. 2005).STAPHYLEACEAE Martynov* Back to CrossosomatalesWoody; ellagic acid 0; wood often fluorescing; fibers with bordered pits; nodes 5:5; petiole bundles annular; mucilage cells +; cuticle waxes as (parallel) platelets; leaves opposite, odd-pinnately compound (uni-, trifoliolate), "glands" or stipels at articulations, stipules interpetiolar or not; inflorescence terminal; K subpetaloid, A = and opposite K, anthers sagittate, pollen microreticulate, G [2-3(4)], odd member adaxial, with (1-)6-12 (basal) ovules/carpel, orientation variable, nucellar cap +, styles free, stigmas connate; fruit a berry, dry inflated and indehiscent, or follicle [Euscaphis], K persistent or not; seeds few, testa multiplicative (vascularised), exotesta palisade (not), mesotesta thick-walled, endotesta slightly thick-walled, unlignified; embryo green, cotyledons large; n = 13.
Staphyleaceae3(?)[list]/45. North temperate, tropics in America (to Bolivia) and Malesia (Map: see van der Linden 1960; Meusel et al. 1978 - esp. inaccurate in South America). [Photo - Fruit] [Photo - Staphylea Flower] [Photo - Staphylea Fruits] * Staphyleaceae are shrubs to trees that may be recognised by their opposite, odd-pinnately compound leaves with serrate leaflets and little "glands" at the articulations (the latter often collapse when dry), the stipules are cauline and are sometimes interpetiolar. The flowers have rather petaloid sepals and usually two to three carpels.The pollen is binucleate according to Kimoto and Tokuoka (1999). The limits of the genera currently accepted are unsatisfactory (Simmons & Panero 2000).Staphyleaceae were placed in Sapindales by Cronquist (1981) and Takhtajan (1997).See Hegnauer (1973, 1990) for chemistry, Carlquist and Hoekman (1985) for wood anatomy, Dickison (1986) for floral morphology, Dickison (1987) for pollen morphology, Ramp (1987) for the gynoecium, and Danilova (1996) for seed structureSynonymy: Ochranthaceae EndlicherStachyuraceae + Crossosomataceae: crystals/druses absent from flowers, anthers X-shaped; funicular aril +; whole testa sclerotic.STACHYURACEAE J. Agardh* Back to CrossosomatalesEvergreen or deciduous shrubs or small trees; ellagic acid +; true tracheids +; nodes 3:3; petiole bundle arcuate; hairs eglandular, (cuticle waxes as tubes); stomata paracytic; leaves spiral; inflorescences axillary, racemose, flowers 4-merous, K decussate, A 2x K, pollen (trinucleate), psilate, hypanthium 0, nectary at base of G, G [4], opposite K, placentation intrusive apical-parietal, many ovules/carpel, style short, compitum down style; fruit a berry, K deciduous; seeds many, coat multiplicative, tegmen obliterated; embryo moderate, cotyledons large; n = (11) 12.
Stachyuraceae1[list]/5. South East Asia (Map: see Chen 1981). [Photo - Habit/Fruits] [Photo - Inflorescence] * Stachyuraceae are small trees or shrubs with closely serrate, stipulate leaves and rather long, pendulous, racemose inflorescences. The sepals and petals of the four-merous flowers are similar, and the fruit is a berry.The leaves have veins running to opaque, deciduous teeth. The micropyle is zig-zag. For pollen, see Jin and Wei (2002); they describe the surface as being foveate and the grains as being 18-28µm in size, larger than those of Tapiscia (see Tapisciaceae, Huerteales) but smaller than the finely reticulate grains of Staphyleaceae (28-40µm).Stachyuraceae were included in Theales by Takhtajan (1997).Details of the flower are taken from Hooker (1882) and of embryology from Mathew and Chaphekar (1977) and Kimoto and Tokuoka (1999); see Hegnauer (1973, 1990) for chemistry and Chen (1981) for a revision of most of the species.CROSSOSOMATACEAE Engler* Back to CrossosomatalesDeciduous shrubs; inulin, ellagic acid +; vessel elements with simple perforations; nodes 1:1, 3:3; yellow acicular crystals common; leaves spiral or opposite (entire), stipules minute, petiolar or 0; (plant polygamo-monoecious); flowers (3-)4-5(-6)-merous, (nectary 0), A 4-many, opposite K or from 10 trunk bundles, tapetal cells polyploid, pollen microreticulate, G 1-5(-9), odd member adaxial, (1-)2-many amphi- or campylotropous ovules/carpel, archesporium multicellular, styles short, stigma also decurrent; fruit coriaceous, opening abaxially; aril fimbriate, endotegmen fibrous; n = 6.
Crossosomataceae4[list]/12. W. North America (Map: from Hannon 2002). [Photo - Crossosoma Collection] * Crossosomataceae are rather small-leaved, much-branched deciduous shrubs that are otherwise vegetatively nondescript. The flowers have separate sepals, petals and carpels and a more or less well developed hypanthium. The dehiscent fruits open down their abaxial surfaces and the seeds have a fimbriate aril.Velascoa has a long hypanthial tube, but it apparently lacks a nectary.Crossosomataceae were included in Rosales by Cronquist (1981) and were sister taxon to Geraniaceae in some early molecular studies (e.g. Price & Palmer 1993).Information is taken from Hegnauer (1964, 1989: chemistry), P. E. Richardson (1968: general), Kapil (1970: embryology, etc.), DeBuhr (1978), Tatsuno and Scogin (1978), Thorne and Scogin (1978), Rzedowski and Rzedowski (1997: new genus), Hannon (2002: review) and Sosa and Chase (2003: phylogeny).Aphloiaceae + Geissolomataceae + Ixerbaceae + Strasburgeriaceae: conspicuous protrusions from pollen apertures.APHLOIACEAE Takhtajan* Back to Crossosomatales
AphloiaceaeEvergreen shrubs or trees; cork pericyclic; nodes 3:3; stomata anisocytic; petiole bundles arcuate; plant glabrous; leaves 2-ranked; inflorescence fasciculate; P ca 7, ?spiral, A many, pollen striate, G 1, ca 10 ovules/carpel, micropyle endostomal, stigma sessile, annular-peltate; fruit a berry, P and A persistent; outer 3-5 testal layers much thickened, then small unthickened cells, then 2-3 layers of elongated unthickened cells; endosperm development?; embryo curved, terete; n = ?1/1 or more: Aphloia theiformis. E. Africa, Madagascar, the Mascarenes and Seychelles (Map: from Serban Proches, pers. comm.). [Photo - Fruit] * Aphloiaceae are undistinguished evergreen shrubs or small trees with distichous, serrate leaves and often persistent stipules. The axillary flowers have a hypanthium, an undifferentiated perianth, many stamens, and a single carpel. Herbarium specimens have a yellowish, crusty material associated with them, rather like some Thymelaeaceae.The hypanthial region is broad and spreading and its surface may be nectariferous. The ovules are possibly campylotropous, and are not simply anatropous.Aphloia used to be included in Flacourtiaceae; it was included in Violales by Takhtajan (1997).Details of the seed coat are in part taken from Takhtajan (1992) while Hegnauer (1989, as Flacourtiaceae) gives a few details of plant chemistry.Geissolomataceae + Ixerbaceae + Strasburgeriaceae: hairs single-celled and T-shaped; pollen ± psilate; G not stipitate, alternate with P/K, with abaxial [dorsal] ribs, two collateral ovules/carpel, stigma punctiform.GEISSOLOMATACEAE Endlicher* Back to CrossosomatalesEvergreen shrubs; plants Al-accumulators; cork outer cortical; nodes 1:1; leaves opposite, margins entire, 2ndary veins palmate, paired projections [?stipules] on petioles; flowers axillary, 4-merous, with 3-4 pairs of basal bracts, P 4, petaloid, basally connate, A adnate to base of P, G [4], styles slender, twisted and connate towards their apices; fruit a capsule surrounded by persistent K; seed carunculate, coat thick-walled; endosperm development?, embryo ?small, cotyledons thin; n = ?
Geissolomataceae1[list]/1: Geissoloma marginatum. Cape Province, South Africa (Map: from Heywood 1978).Geissolomataceae were included in Celastrales by Cronquist (1981), in Ericanae by Takhtajan (1997).For information on nodal anatomy, R. A. Howard (pers. comm.); general information is taken from Baillon (1875) and Dahlgren and van Wyk (1988, "micropyle endostomal", but cf. Stephens 1910), seed coat from Danilova (1996).Ixerbaceae + Strasburgeriaceae: nodes 3:3; cells with thickened mucilaginous inner tangential walls [in flowers, at least]; acicular crystals +; leaves spiral, margins gland-toothed; flowers large; K spiral, C clawed, filaments flattened, anthers >3mm long, ovules sessile, epitropous, style long; style persistent in fruit.For general information, see Cameron (2003).IXERBACEAE Grisebach* Back to CrossosomatalesEvergreen trees; non-hydrolysable tannins 0; cork?; pits vestured; petiole bundles arcuate; stipules 0; inflorescence terminal, umbellate; A = and opposite K, pollen 4-5-colporate, disc lobed opposite C, G [5], funicular obturator +, style strongly ridged and spiral at apex; fruit a capsule, carpels also splitting adaxially, valves woody, reflexed, K deciduous; seeds shiny, with a broad "aril", hilar scar elongated, exotestal and adjacent cells thickened; endosperm development?, cotyledons large; n = ?
Ixerbaceae1/1: Ixerba brexioides. North Island, New Zealand. * Ixerbaceae are evergreen trees with pseudoverticillate and strongly toothed but estipulate leaves. The inflorescences are terminal and the flowers are rather large and have five spreading sepals and petals, ten stamens with thick connectives, and a conspicuous ovary gradually tapering into the style and with a spreading, lobed nectary at its base. The capsular fruit has a few shiny black seeds with a conspicuous red aril.Glands like those of leaf margin are in a cauline stipular position in seedlings. The vascular bundles in the receptacle are clustered.Ixerba was placed in Grossulariaceae by Cronquist (1981), in Brexiaceae by Airy Shaw (1966: note the specific epithet), and in Rosidae-Brexiales by Takhtajan (1997).Details of anatomy are taken from Gregory (1998: in Escalloniaceae) and Hils (1985) while Hegnauer (1973, as Saxifragaceae) gives some information on chemistry.STRASBURGERIACEAE Solereder* Back to CrossosomatalesEvergreen trees; chemistry?; stem with cortical bundles; nodes 3:3 or 5:5; cuticle waxes as almost thread-like scales; leaf teeth with a single vein and opaque deciduous cap, stipules intrapetiolar, connate basally; flowers axillary; K 8-10, C 5 (6), A 10, in a single whorl, latrorse, connective thick, anthers attached their length, hypanthium 0, nectary on G, G [4-7], adnate to central column, 1 ovule/carpel, stigmas lobed; fruit rather dry, indehiscent, K persistent; exotesta of 5-12 layers of crystalliferous sclereids; endosperm moderate; n = ca 250.1[list]/1: Strasburgeria calliantha. New Caledonia, on ultrabasic rocks. [Photo - Flower] * Strasburgeriaceae are evergreen trees that may be recognised by their rather large, spiral and toothed leaves that have intrapetiolar stipules. The flowers are large and axillary and have spiral sepals, five petals and ten stamens with long anthers attached their lengths to the thick connective. The fruit is indehiscent.Tertiary pollen like that of Strasburgeria has been found from Australia, Tasmania, and New Zealand.As Amaral (1991) suggested, Strasburgeria is to be excluded from Ochnaceae - i.a. it lacks cristarque cells and has crassinucellate ovules.See also Dickison (1981) and Cameron (2001) for information.
EXTANT SEED PLANTSPlant woody, evergreen; nicotinic acid metabolised to trigonelline; vascular cambium + [xylem differentiating internally, phloem externally]; stem xylem endarch, root xylem exarch; leaves with gaps, spiral, simple, buds axillary, prophylls [including bracteoles] two, lateral; true pollen +, mono[ana]sulcate, pollen exine and intine homogeneous, endexine lamellate, ovules unitegmic, crassinucellate; male gametophyte development exosporic, with two gametes, gametes with cell walls; seeds large, embryo straight, white, cotyledons 2; mitochondrial nad1 intron 2 present.MAGNOLIOPHYTALignans, O-methyl flavonols, dihydroflavonols, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, cyanogenesis via tyrosine pathway, lignins derived from both coniferyl and sinapyl alcohols, containing syringaldehyde [in positive Maüle reaction], and hemicelluloses as xyloglucans; root apical meristem intermediate-open; root vascular tissue oligarch [di- to pentarch], lateral roots arise opposite or immediately to the side of [when diarch] xylem poles; cork cambium in root deep-seated, trichoblasts [differentiated hair-forming cells] 0, origin of epidermis with no clear pattern [probably from inner layer of cap]; stem with 3-layered tunica-corpus construction; stem cork cambium superficial; wood fibers and wood parenchyma +; circular bordered pits lacking margo and torus; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides; tracheids +; sieve tubes eunucleate, with sieve plate, companion cells from same mother cell that gave rise to the sieve tube and P proteins, plastids with starch grains alone; nodes unilacunar; stomata paracytic; leaves with petiole and lamina [the latter formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, vein endings free; flowers perfect, polysymmetric, parts spiral [esp. the A], free, numbers unstable, P not differentiated, outer members not enclosing the rest of the bud, A many, development centripetal, with a single trace, introrse, filaments stout, anther ± embedded in the filament, tetrasporangiate, dithecal, with at least outer secondary parietal cells dividing, hypodermal endothecium +, cells elongated at right angles to long axis of anther, tapetum glandular, binucleate, microsporogenesis ?, pollen binucleate at dispersal, trinucleate eventually, endexine compact, tube elongated, gametes 2, with cell walls, nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, ovules marginal, anatropous, bitegmic, micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin, chalazal, female gametophyte ?4-nucleate, unipolar, style short, stigma ± decurrent, wet [secretory]; P deciduous in fruit; seed exotestal; double fertilisation +, endosperm ?diploid, cellular [first division oblique, micropylar end initially with a single large cell, chalazal end more actively dividing], copious, oily and/or proteinaceous, embryo cellular ab initio, small-minute; sympodial seedlings/young plants; Arabidopsis-type telomeres [(TTTAGGG)n]; whole genome duplication, single copy of LEAFY and RPB2 gene, knox genes extensively dupicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, duplication producing SEP3/LOFSEP gene pair.Possible apomorphies are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear, because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied. Furthermore, details of relationships among gymnosperms will affect the level at which some of these characters are pegged.Magnoliales, i.e. the magnoliid clade; Chloranthales, Ceratophyllales, monocots and eudicots are the other clades involved. Back to Main TreeMyricetin, delphinidin scattered, ethereal oils 0, asarone 0 [unknown in some groups, + in some asterids]; root epidermis derived from root cap [?Buxaceae, etc.]; stomata anomocytic; flowers (dimerous), cyclic, P members with a single trace, A (opposite P), few, (polyandry widespread), filaments fairly slender, anthers basifixed, pollen tricolpate, G with complete postgenital fusion, style solid [?here]; seed coat?Tricolpate pollen from 120-125 mybp is known (for the possible functional significance of the evolution of triaperturate pollen, see Furness & Rudall 2004), and an age of some 125 my for the eudicots seems reasonable (e.g. Magallón et al. 1999; Sanderson & Doyle 2001; Anderson et al. 2005), although Wikström et al. (2003) suggest an age of 131-147 mybp for the clade.Note that cuticle waxes as clustered tubules, nonacosan-10-ol the main wax could be optimised to this position, being lost in Sabiaceae, Platanaceae, Buxales, and perhaps also in the internode below Gunnerales... (but present in a few Santalales, also in woody Saxifragales: see Barthlott et al. 2003). Dimerous flowers are scattered through the basal eudicot grade, but are at least very uncommon in the core eudicots (Drinnan et al. 1994; Soltis et al. 2003). Stamens are also quite often inserted opposite the tepals in the basal eudicot grade. Taxa with androecia that are initiated as antesepalous triplets are scattered (but really rather uncommon) throughout the group (Hufford 2001a). See Hegnauer (1990) for a discussion of the chemistry of the Polycarpicae, which also includes the magnoliids and Austrobaileyales. Dumortier* Back to Main Tree(O-methyl)flavonols, flavonols +; vessel elements?; young stem with separate bundles, vessels only in central part, true tracheids +; rays exclusively wide multiseriate [and in wood, where present]; (wood fluorescence +); cambium storied; nodes 3:3; sieve tube plastids large S-type; petiole bundles annular; cuticle waxes as clustered tubules, nonacosan-10-ol the main wax; leaves spiral, ?teeth; G opposite P; P deciduous in fruit; seed exotestal; endosperm development?, embryo size?Anderson et al. (2005) date stem group Ranunculales at 122-120 mybp, divergence within it beginning 121-114 mybp. All families diverge before 105 mybp except Ranunculaceae/Berberidaceae (104-90 mybp). See Anderson et al. (2005) for further details of the timing of diversification within the clade.
Page last updated: Sat, 05 Nov 2005 23:59:19 GMT This clade - perhaps especially Menispermaceae and Ranuculaceae - is not much used as food plants of butterfly caterpillars (Ehrlich & Raven 1964). Ranunculales contain ca 1.6% of eudicot diversity. Magallön et al. (1999) suggest an age of ca 70 mybp for them, based on the earliest fossil occurence assignable to it, however, this is a member of the decidely non-basal Menispermaceae.Berberin, common in the order, is synthesised via the tyrosine pathway. Gleissberg and Kadereit (1999) discuss the evolution of leaf form in the order, with polyternate/acropetal/basipetal-pedate leaves perhaps being plesiomorphic. The glandular leaf teeth have a clear, persistent, swollen cap into which higher order lateral veins also run. What is the distribution of colleters? Drinnan et al. (1994) suggest that petals have been derived from stamens several times in the order, examples would include Lardizabalaceae. Tamura (1965) summarises evidence for the staminal nature of the petals in Ranunculaceae: petals have a single trace, are in the same parastiches as androecial members, are similar to stamens in early development, and are often peltate. Is the pollen endexine ever lamellate? Antipodal cells are commonly other than simply persistent; data are summarised in Williams and Friedman (2004).Relationships in the order are fairly well understood - see Hoot and Crane (1995), Kadereit et al. (1995), Oxelman and Lidén (1995), and Hoot et al. (1999: three genes). However, both Soltis et al. (2003a) and a recent four-gene analyses (Kim et al. 2004) suggest that Eupteleaceae may be sister to the whole of the rest of the order, although with only moderate support, and this is the topology adopted here. APG II allows as an option the possibility of including Papaveraceae, Fumariaceae, and Pteridophyllaceae in an expanded Papaveraceae, which I follow here (see also Judd et al. 2002). Papaverales are commonly recognised as a separate order next to Ranunculales (Cronquist 1981; Dahlgren 1989), but there is no point in recognising them, especially given the uncertainty of the position of Eupteleaceae.For information, see Ernst (1964: general), Hennig et al. (1994: cuticle waxes), Drinnan et al. (1994: floral evolution), Barthlott and Theisen (1995: cuticle waxes), Carlquist (1995b: wood anatomy), Endress (1995: floral morphology), Floyd et al. (1999) and Floyd and Friedman (2000: endosperm)
Includes Berberidaceae, Eupteleaceae, Circaeasteraceae, Lardizabalaceae, Menispermaceae, Papaveraceae (inc. Fumarioideae Papaveroideae, Pteridophylloideae), Ranunculaceae. Synonymy: Berberidales Dumortier*, Eupteleales Reveal*, Glaucidiales Reveal*, Helleborales Nakai, Hydrastidales Takhtajan*, Lardizabalales Loconte*, Menispermales Bromhead*, Nandinales Doweld, Papaverales Dumortier*, Podophyllales Dumortier - Berberidanae Doweld, Ranunculanae Reveal* - Ranunculidae Reveal* - Berberidopsida Brogniart, Papaveropsida Brongniart, Ranunculopsida BrongniartBack to RanunculalesDeciduous trees; (dihydro)chalcones +; cork deep in cortex; vessel elements with scalariform-reticulate perforations; broad rays?; nodes 1:many; idioblasts?; cuticle wax crystalloids 0; bud scales +; leaves subplicate-conduplicate, margins gland-toothed, 2ndary veins pinnate; inflorescence axillary, fasciculate or umbellate; flowers (staminate), disymmetric; P 0, A 6-20, anthers valvate, latrorse, connective prolonged, G 6-31, stipitate, "intermediate ascidiate", 1-2(-4) epitropous ovules/carpel, outer integument 4-5 cells across, micropyle bistomal, stigma at most weakly secretory, brush-like; fruit a samara; seed with ± enlarged exotestal cells (sclerotic mesotesta), endotesta lignified subpalisade; endosperm cellular; n = 14. 1[list]/2. Temperate South East Asia (Map: from Fu & Hong 2000). [Photo - Collection]
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