LIGNOPHYTA

True roots +; lateral meristems: cork cambium producing cork abaxially, vascular cambium producing phloem abaxially and xylem adaxially.

EXTANT SEED PLANTS/SPERMATOPHYTA

Plant woody, evergreen; nicotinic acid metabolised to trigonelline, (cyanogenesis via tyrosine pathway); primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignins derived from (some) sinapyl and particularly coniferyl alcohols, thus containing p-hydroxyphenyl and guaiacyl lignin units, (lignins derived from p-coumaryl alcohol, i.e. S [syringyl] lignin units); true roots present, apex multicellular, xylem exarch, and branching endogenous; arbuscular mycorrhizae +; shoot apical meristem multicellular, interface specific plasmodesmatal network; stem with ectophloic eustele, endodermis 0, xylem endarch, branching exogenous; vascular tissue in t.s. discontinuous by interfascicular regions; vascular cambium + [xylem ("wood") differentiating internally, phloem externally]; wood homoxylous, tracheids and rays alone, tracheid/tracheid pits circular, bordered; mature sieve tube/cell lacking functioning nucleus, plastids with starch grains; phloem fibres +; stem cork cambium superficial, root cork cambium deep seated; leaves with single trace from sympodium ["nodes 1:1"]; stomata ?; leaf vascular bundles collateral; leaves megaphyllous [determinancy evolved first, then ad/abaxial symmetry], spiral, simple, lamina with vein density up to 5 mm/mm² [mean for all non-angiosperms 1.8]; axillary buds associated with at most some leaves; prophylls [including bracteoles] two, lateral; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated in indeterminate cones/strobili; true pollen [microspores, i.e. no distal pore for release of gametes] +, grains mono[ana]sulcate, exine and intine homogeneous; ovules unitegmic, crassinucellate, megaspore tetrad tetrahedral, only one megaspore develops, megasporangium indehiscent; male gametophyte development first endo- then exosporic, tube developing from distal end of grain, to ca 2 mm from receptive surface to egg, gametes two, developing after pollination, with cell walls, with many flagellae; female gametophyte endosporic, initially syncytial, walls then surrounding individual nuclei; seeds "large", first cell wall of zygote transverse, embryo straight, endoscopic [suspensor +], short-minute, with morphological dormancy, white, cotyledons 2; plastid transmission maternal; two copies of LEAFY gene, PHY gene duplications [three - [BP [A/N + C/O]] - copies], nrDNA with 5.8S and 5S rDNA in separate clusters; mitochondrial nad1 intron 2 and coxIIi3 intron and trans-spliced introns present.

MAGNOLIOPHYTA

Lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, non-hydrolysable tannins, quercetin and/or kaempferol +, apigenin and/or luteolin scattered, [cyanogenesis in ANITA grade?], S [syringyl] lignin units common, positive Maüle reaction [syringyl:guaiacyl ratio more than 2-2.5:1], 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; origin of epidermis with no clear pattern [probably from inner layer of root cap], trichoblasts [differentiated root hair-forming cells] 0; shoot apex with tunica-corpus construction, tunica 2-layered; reaction wood ?, with gelatinous fibres; starch grains simple; primary cell wall mostly with pectic polysaccharides, poor in mannans; tracheid:tracheid [end wall] plates with scalariform pitting, wood parenchyma +; sieve tubes enucleate, sieve plate with pores (0.1-)0.5-10< µm across, cytoplasm with P-proteins, cytoplasm not occluding pores of sieve plate, companion cells from same mother cell that gave rise to the sieve tube; sugar transport in phloem passive; nodes unilacunar [1:?]; stomata with ends of guard cells level with pore, paracytic, outer stomatal ledges producing vestibule; leaves petiolate, lamina [formed from the primordial leaf apex], development of venation acropetal, 2ndary veins pinnate, fine venation reticulate, veins (1.7-)4.1(-5.7) mm/mm², endings free; most/all leaves with axillary buds; flowers perfect, pedicellate, polysymmetric, parts spiral [esp. the A], free, numbers unstable, development in general centripetal; P not sharply differentiated, with a single trace, outer members not enclosing the rest of the bud, often smaller than inner members; A many, filament not sharply distinguished from anther, stout, broad, with a single trace, anther introrse, tetrasporangiate, sporangia in two groups of two [dithecal], ± embedded in the filament, with at least outer secondary parietal cells dividing, each theca dehiscing longitudinally by action of hypodermal endothecium, endothecial cells elongated at right angles to long axis of anther; tapetum glandular, binucleate; microspore mother cells in a block, microsporogenesis successive, walls developing by centripetal furrowing; pollen subspherical, tectum continuous or microperforate, ektexine columellar, endexine thin, compact, lamellate only in the apertural regions; nectary 0; G free, several, ascidiate, with postgenital occlusion by secretion, stylulus short, hollow, cavity not lined by distinct epidermal layer, stigma ± decurrent, dry [not secretory]; ovules few [?1]/carpel, marginal, anatropous, bitegmic, micropyle endostomal, outer integument 2-3 cells across, often largely subdermal in origin, inner integument 2-3 cells across, often dermal in origin, parietal tissue 1-3 cells across [crassinucellate], nucellar cap?; megasporocyte single, hypodermal, megaspore tetrad linear, functional megaspore chalazal, lacking sporopollenin and cuticle; female gametophyte four-celled [one module, nucleus of egg cell sister to one of the polar nuclei]; P deciduous in fruit; seed exotestal; pollen binucleate at dispersal, trinucleate eventually, germinating in less than 3 hours, pollination siphonogamous, tube elongated, growing at 80-600 µm/hour, with pectic outer wall, callose inner wall and callose plugs, growing between cells, penetration of ovules via micropyle [porogamous] within ca 18 hours, distance to first ovule 1.1.-2.1 mm, tube moves between nucellar cells; double fertilisation +, endosperm diploid, cellular [micropylar and chalazal domains develop diffently, first division oblique, micropylar end initially with a single large cell, divisions uniseriate, chalazal cell smaller, divisions in several planes], copious, oily and/or proteinaceous, embryo cellular ab initio, minute; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)_n]; whole genome duplication, ndhB gene 21 codons enlarged at the 5' end, single copy of LEAFY and RPB2 gene, knox genes extensively duplicated [A1-A4], AP1/FUL gene, paleo AP3 and PI genes [paralogous B-class genes] +, with "DEAER" motif, SEP3/LOFSEP and three copies of the PHY gene, [PHYB [PHYA + PHYC]].

Evolution. Possible apomorphies for flowering plants are in bold. Note that the actual level to which many of these features, particularly the more cryptic ones, should be assigned is unclear. This is because some taxa basal to the [magnoliid + monocot + eudicot] group have been surprisingly little studied, there is considerable homoplasy as well as variation within and between families of the ANITA grade in particular for several of these characters, and also because details of relationships among gymnosperms will affect the level at which some of these characters are pegged. For example, if reticulate-perforate pollen is optimized to the next node on the tree (see Friis et al. 2009 for a discussion), it effectively makes the pollen morphology of the common ancestor of all angiosperms ambiguous... For other features such as details of sugar transport in the phloem, their placement on the tree is frankly speculative. Finally, for features such as parietal tissue/a nucellus only one (Nymphaeales) to three cells thick above the embryo sac and a stylar canal lacking an epidermal layer, although plesiomorphous for basal grade angiosperms (Williams 2009), I am unsure where on the tree a thicker nucellus and a stylar epidermal layer are acquired.

NYMPHAEALES [AUSTROBAILEYALES [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]: vessels +, elements with elongated scalariform perforation plates; wood fibres +; axial parenchyma diffuse or diffuse-in-aggregates; tectum reticulate-perforate [here?]; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.

Phylogeny. Relationships of the main groups within commelinids are unclear; for further information, see discussion preceding Dasypogonaceae, also Zingiberales and Poales.

[POALES [COMMELINALES + ZINGIBERALES]]: primary cell wall mostly with glucurono-arabinoxylans; stomata subsidiary cells with parallel cell divisions; endosperm reserves starchy.

[COMMELINALES + ZINGIBERALES]: inflorescences indeterminate, but with many-flowered cincinnal branches [helicoid cymes]; tapetum invasive or plasmodial.   Back to Main Tree

Evolution. Divergence & Distribution. The stem group dates to ca 116 million years before present, divergence of the two clades to ca 114 million years before present (Janssen & Bremer 2004), while the figures in Wikström et al. (2001) are 87-83 and 81-73 million years before present respectively, while Bremer (2000b: largely fossil calibrations) dates the stem group to ca 108 million years before present, divergence to ca 84 million years before present. More recent dates in Kress and Specht (2006) are ca 124 (stem group) and 110-80 (divergence) million years before present while Magallón and Castillo (2009) estimate ca 109.7 and 99.9 million years for relaxed and constrained penalized likelihood datings for the stem group.

Floral Biology & Seed Dispersal. Monosymmetric flowers in this clade, especially in Zingiberales and Haemodoraceae, have a variety of very different morphologies; for monosymmetry, see Rudall and Bateman (2004). Indeed, monosymmetric flowers could be optimised to the node [Commelinales + Zingiberales], as by Endress (2011a), who suggested that it might be a key innovation here.

Chemistry, Morphology, etc. For phenyphenalenones, see Otálvaro et al. (2002). Tapetal variation in those few Zingiberales studied is extensive (Prakash et al. 2000; Furness & Rudall 2001; Simão et al. 2007).

Phylogeny. In previous studies this group has sometimes been rather weakly supported (e.g. Chase et al. 2000a; Davis et al. 2004: Givnish et al. 2006b, one gene), although it has 100% support in the multi-gene analysis of S. W. Graham et al. (2006) and Chase et al. (2006) and good support in the multigene (but poor sampling) study of Soltis et al. (2011).

For phenyphenalenones, see Otálvaro et al. (2002), for monosymmetry, see Rudall and Bateman (2004).

COMMELINALES Dumortier  Main Tree, Synapomorphies.

Mycorrhizae absent; (phenyphenalenones +); vessel elements with scalariform perforation plates; cuticle waxes not as aggregated rodlets; (flower enantiostylous); seed coat testal and tegmic; endosperm abundant, helobial, cell wall formation in small chalazal chamber precedes that in large micropylar chamber; collar rhizoids +. - 5 families, 68 genera, 812 species.

Evolution. Divergence & Distribution. Stem-group Commelinales are dated to ca 114 million years before present, divergence within the group to ca 110 million years before present (Janssen & Bremer 2004); the corresponding dates in Wikström et al. (2001) are 81-73 and 71-66 million years before present respectively. Magallón and Castillo (2009) estimate ca 110 and 99 million years for relaxed and constrained penalized likelihood datings for the stem group, the stem group being 123 to 111 million years old (relaxed and constrained estimates).

Chemistry, Morphology, etc. Tapetal raphides are known from Commelinaceae, Philydraceae and Haemodoraceae, but their general distribution is unclear (Hardy & Stevenson 2000; Prychid et al. 2003a); there may be systematically interesting variation in the pattern of endothecial thickenings (Manning 1996). A five base pair insertion in the matK gene in members of Hanguanaceae and Pontederiaceae was found by Tamura et al. (2004a), it was absent in Haemodoraceae, but no other taxa were sampled.

Phylogeny. For relationships, see Givnish et al. (1999), Hopper et al. (1999), S. W. Graham et al. (2006), Chase et al. (2006) and Saarela et al. (2008); Graham (in Graham et al. 2002) noted that there was very strong support for the grouping [Haemodoraceae + Pontederiaceae]. Janssen and Bremer (2004) suggest a rather different - and perhaps unlikely - set of relationships - [Philydraceae [Hanguanaceae [Haemodoraceae [Commelinaceae + Pontederiaceae]]]], and the dates here are based on this topology; Givnish et al. (2006b: ndhF gene only) also found Philydraceae to be sister to other Commelinales, but the position had little support.

There has been much discussion over the position of Hanguanaceae, which in morphological analyses tends to cluster - sometimes quite strongly - with Zingiberales, although it lacks the inferior ovary of members of that order. Molecular analyses suggest the inclusion of Hanguanaceae in Commelinales. Thus Givnish et al. (1999: rbcL analysis) found that Hanguanaceae were sister to Commelinaceae, while Rudall et al. (1999: general) found Hanguanaceae to show a rather strong association with Zingiberales, the positions of other members of Commelinales were also perhaps unexpected; the former position is accepted here (see also Davis et al. 2004).

Includes Commelinaceae, Haemodoraceae, Hanguanaceae, Philydraceae, Pontederiaceae.

Synonymy: Haemodorales Martius, Hanguanales Reveal, Philydrales Dumortier, Pontederiales Martius

[Hanguanaceae + Commelinaceae]: cotyledon not photosynthetic.

HANGUANACEAE Airy Shaw   Back to Commelinales

Hairs multicellular, branched; mucilage canals +; epicuticular waxes 0; leaves spiral, with petiole, midrib and cross veins; plant dioecious; inflorescence branched-spicate, flowers sessile; T pseudomonocyclic, small; staminate flowers: filaments broadened and connate at very base; ?tapetum; pollen inaperturate, exine spinulose; pistillode +; carpellate flowers: staminodes nectar-secreting; G with intra-ovarian trichomes and mucilage, style ± 0, stigmas 3; ovule 1/carpel, basal, straight, micropyle?, parietal tissue absent, epidermal cells anticlinally elongated, suprachalazal zone massive; fruit a 1-seeded berry; seed bowl-shaped [placenta inside the bowl!]; testa ca 5 cells across, endotesta with inner periclinal walls thickened, tegmen with two layers of crossing fibres; endosperm type?, embryo small; n = ca 24, 36, 45, chromosomes 1> µm long; primary root well developed.

1[list]/10. Sri Lanka, South East Asia to Palau and N. Australia (map: see Hewson 1986). [Photo - Fruit]

• Hanguanaceae are robust terrestrial herbs that have petiolate leaves with a midrib, many parallel veins, and prominent cross veins. The inflorescence is a panicle with sessile, small, and undistinguished flowers. The fruit is a single-seeded berry, and the seed itself is bowl-shaped as it comes to surround the placenta during development.

Evolution. Divergence & Distribution. Hanguanaceae diverged from other Commelinales ca 104 million years before present (Janssen & Bremer 2004).

Chemistry, Morphology, etc. Raphides may occur, but they are rare (Prychid & Rudall 1999). In Takhtajan (1985) there are illustrations of a several-layered testa and a massively-thickened tegmen with crossing fibres. However, Tillich (1996) described the seed coat as being testal - but his outer layer seems comparable to Takhtajan's endotesta and his inner layer to one of the tegmic layers...

Additional information is taken from Tillich (1996: seedling), Bayer et al. (1998b: general), Tillich and Sill (1999: general), Givnish et al. (1999: rbcL), and Rudall et al. (1999: a great deal).

Previous Relationships. Hanguana was often included in Flagellariaceae (now in Poales), while more recent morphological studies have linked them with Zingiberales (see above).

COMMELINACEAE Mirbel, nom. cons.   Back to Commelinales

Rather succulent herbs; 6-hydroxyflavonoids +; vessels also in stem; hairs uniseriate; stem with swollen nodes; (prophylls lateral); leaves spiral (two-ranked), midrib prominent, sheath closed; andromonoecy common; inflorescences axillary (terminal), (boat-like bracts conspicuous); flowers open one day; P = K + C, C deliquescent; (G [2]), septal nectaries 0; ovules 1-many/carpel, straight to campylotropous, micropyle (exo)/endostomal (ovule naked), outer integument 3-7(-10) cells across, inner 2, (parietal tissue absent, or -2 cells across), nucellar cap to 2 cells across; endocarp with fibres in vertical series, transversely elongated (cross-shaped - Forrestia), variously thickened; (seeds uniseriate); exotesta thin, endotesta silicified, operculum ["embryotega"] +; endosperm nuclear, embryo marginal, chalazal haustorium +, suspensor 0; n = 4³; coleoptile +.

40[Genera List]/652. Tropical and temperate.[Photos - Collection.]

Cartonematoideae G. C. Tucker

SiO₂ bodies 0; stem collenchyma 0; raphide canals next to veins or 0; stomata paracytic or tetracytic; glandular microhairs 0, although plant glandular pubescent; inflorescence racemose; flowers sessile, yellow; ?tapetum; fruit a berry; operculum lacking collar, most of testa sloughed off; collar short, mesocotyl +, primary root strong; n = 12.

2/12. Australasian, Triceratella (to be included?) Zimbabwe (map: from FloraBase ix.2010; GBIF ix.2010).

Synonymy: Cartonemataceae Pichon, nom. cons.

Commelinoideae Eaton

Cyanidin 3,7,3'-triglucoside +; stem collenchyma +; vessel elements with simple perforation plates, also in stem and leaf; stem with narrow cortex and endodermis-like sheath enclosing vascular bundles that connect only at the nodes; (SiO₂ bodies +); raphide canals between veins; stomata tetracytic, etc.; 3-celled glandular microhairs +; (leaf vernation involute); (inflorescence axillary; prophyll lateral); flowers (obliquely monosymmetric; enantiostylous); K/C, or T, 1- or 3- trace, blue, pink or white (yellow), (C tubular); A 1-6, (adnate to C), anthers poricidal, with 2+ fibrous middle layers, (connective [much] expanded), filaments often with dense uniseriate hairs, staminodes often 2-4, attractive; pollen with raphides; (embryo sac bi- or tetrasporic, 8[haploid]-nucleate), (antipodal cells ± persisting - Tinantia), polar nuclei fuse early; seed endotestal, (also exotegmic), operculum ["embryotega"] testal, with a micropylar collar [position varies]; starch grains complex; n =4<, often "large".

38/640: Commelina (170), Tradescantia (70), Aneilema (68), Murdannia (50), Cyanotis (50). Tropical, also temperate, not Europe (map: see Heywood 1978; Fl. N. Am. 22: 2000; FloraBase 2004). [Photo - Flower] [Photo - Flower]

Synonymy: Ephemeraceae Batsch, nom. rej., Tradescantiaceae Salisbury

• Commelinaceae are herbs with rather soft and fleshy leaves; these have closed sheaths and some species have the two sides of the blade rolled towards the middle in bud. The inflorescences usually consist of many-flowered helicoid cymes that are often subtended by large, leafy bracts; they are quite often leaf-opposed. The flowers usually last for one day only and are frequently blue or pink; when they are monosymmetric they are usually held with the median petal in the abaxial position. The filaments are often conspicuously hairy.

Evolution. Divergence & Distribution. Stem group Commelinaceae are dated to ca 89 million years before present, divergence within it to ca 62 million years before present (Janssen & Bremer 2004), however, members of Cartonematoideae were not included in the study, so the latter date reflects divergence within Commelinoideae. Also, the topology of the tree on which this date is based is different from that used here.

Chemistry, Morphology, etc. Remizowa et al. (2011) suggested that the apparently cymose part inflorescences of Tradescantia were in fact racemose, but c.f. e.g. Panigo et al. (2011). On the other hand, the apparently racemose inflorescences of Cartonema have been described as having one flower/cincinnus (Brenan 1966). Leaf-opposed inflorescences and axillary inflorescences that perforate the leaf sheath as they emerge (as in Buforestia) are known from the family. Enantiostyly occurs, but is uncommon. The expression of monosymmetry may change during the development of the flower (Hardy et al. 2004). In Dichorisandra the bracteoles are more or less lateral and the plane of symmetry of the flower is transverse, in other taxa it may be oblique (e.g. Eichler 1875). In general, floral symmetry and basic construction is quite variable. Flower may be monosymmetric by the corolla, one petal being much reduced in Commelina, or primarily by the androecium. The development of the asymmetric flowers of Cochliostemon has been studied in some detail (Hardy & Stevenson 2000a). In at least some Commelinaceae the inner tepals have only a single trace. There may be tepals, or a calyx and corolla. Weldenia has a long floral tube, but the the tube can be formed by connation of the petals, as in Weldenia, or by adnation of alternating corolla and the filaments of the antisepalous stamens (Rohweder 1979b). Variation in androecial development is extreme, and in some taxa androecial development has been reported as being centrifugal, perhaps a variant of obdiplostemony (Hardy & Stevenson 2000b, but see Endress 2010d).

Indehiscent geocarpic fruits may be produced by Commelina bengalensis and Tapheocarpa. Mabberley (1987) suggested that some taxa may have a small second cotyledon, but to what structure this might refer is unclear. Tillich (1995) described the cotyledon as being of the dropper type. Seedling leaves and often those at the base of axillary shoots are often two-ranked even in those taxa that have spiral leaves predominating in the vegetative plant.

Some information is taken from Rohweder (1963, 1970b: general), Maheshwari and Baldev (1959) and Chikkmannaiah (1963 and references), both embryology, Tomlinson (1966: anatomy), Jones and Jopling (1972: cytology), Stirton and Harborne (1980: anthocyanins - see cyanidin 3,7,3'-triglucoside distribution, but Cartonematoideae not sampled), MartÍnez and Swain (1985: flavonoids), Faden and Hunt (1991: general, classification of family), Faden (1998: general), Hardy et al. (2000b, 2004: floral development), Choob and Mavrodiev (2001: prophylls, etc), Hofreiter and Tillich (2002: root anatomy, quite a bit of variation), Burns et al. (2008: vegetative morphology) and Calderón et al. (2009: ecdysteroids).

Phylogeny. A morphological phylogeny shows little resolution, although anatomical characters gave significantly more support for the rbcL phylogeny than did othet kinds of characters (Evans et al. 2000, cf. Evans et al. 2003). Perhaps not surprisingly, most taxa with strongly monosymmetric flowers form a clade, but Triceratella is widely separated from Cartonema, which is sister to the rest of the family. Evans et al. (2000) discuss the variety of pathways of stomatal development found in the family. Givnish (2003, summary tree only, no support values) emphasized the discordance between relationships suggested by morphological data, which did not retrieve a monophyletic Commelineae and Tradescantieae largely because of high homoplasy of androecial characters, and molecular (rbcL) data, which did find these tribes to be monophyletic (with the exception of Floscopa, see above; Calisia [Tradescantieae] had a similarly isolated position in the morphological analyses). Evans et al. (2003: rbcL phylogeny, Triceratella not studied) also note conflict between morphology and molecules.

Within Commelinoideae, a monophyletic Commelineae and Tradescantieae can be recognised, with Floscopa (chromosomes 3³ µm long), previously included in Tradescantieae, as sister to both (Givnish 2003). Commelineae have stomata with 6 subsidiary cells, spiny pollen and chromosomes ca 1-5 µm long; monosymmetric flowers are commonest here and anther hairs, if present, are not moniliform. Tradescantieae have stomata with 2-6 subsidiary cells, moniliform hairs and chromosomes ca 2-10 µm long (cf. Judd et al. 2002); flowers with tepals (i.e. not differentiated into sepals and petals) are commonest in this clade. Wade et al. (2006) carried out a two-gene analysis of Tradescantieae; the position of Palisota is still unresolved, while Burns et al. (2011), in an extensive analysis of Commelinoideae (no Cartonematoideae included), found Commelineae and Tradescantieae to be moderately supported, with Palisota and Spatholirion with moderately support as successive sister taxa to Commelineae. Callisia, of Tradescantieae, are para/polyphyletic. Spalink et al. (2009) outlined relationships in Aneilema.

Classification. Wade et al. (2006) provide a subtribal classification of Tradescantieae based on a two-gene analysis; some subtribes are paraphyletic.

[Philydraceae [Haemodoraceae + Pontederiaceae]]: SiO₂ bodies 0; styloids +; T with tannin cells; sclereids in placentae; T persistent in fruit.

PHILYDRACEAE Link, nom. cons.   Back to Commelinales

Proanthocyanins +; stem vascular tissue various; (stomata tetracytic); hairs often wooly; leaves usuually two-ranked, equitant and isobifacial [oriented edge on to the stem]; inflorescence racemose, groups of flowers [?arrangement] in axils of spathe-like bracts; flowers open for one day, enantiostylous; T petaloid, outer members 2, large [adaxial = 2 outer T plus adnate adaxial inner T all fused], inner T 2, lateral, small; A 1, abaxial member of outer whorl, (anther coiled); tapetum secretory; pollen with raphides, (in tetrads); septal nectaries 0, (style impressed), stigma large; ovules many/carpel, integuments 1-2/2-3, (parietal tissue 2 cells across), ± postament, hyopostase, funicular obturator +; (seed with caruncle [from outer integument] and chalazal processes); exotesta with thick cellulose walls, (cells spiralling around seed), endotegmen tanniniferous, operculum tegmic; endosperm also with oil and crystalline aleurone bodies, chalazal haustorium +, chalazal chamber cellular ab initio, embryo long, suspensor hardly developed; n = 8, 16, 17; cotyledon linear, bifacial.

4[list]/5. Australia (all genera) to Southeast Asia (map: from Adams 1987; Hamann 1998b).

• Philydraceae can be recognised by their two-ranked, isobifacial-ensiform leaves - although Philydrella lacks these vegetative characters - inflorescences with wooly hairs, and their distinctive monosymmetric flowers. These have a two-merous perianth, the outer whorl usually being much larger than the inner, and a single stamen.

Evolution. Divergence & Distribution. Stem group Philydraceae are dated to ca 110 million years before present, divergence within the crown group to ca 47 million years before present (Janssen & Bremer 2004).

Chemistry, Morphology, etc. Information is taken from Malmanche (1919: anatomy), Kapil and Walia (1965: embryology of Philydrum), Tillich (1994: seedlings) and Hamann (1962b: endosperm, 1966: extensive details, 1998: general).

Phylogeny. For phylogenetic relationships within Philydraceae, see Saarela et al. (2008); Philydrella is sister to the rest of the family.

[Haemodoraceae + Pontederiaceae]: phenylphenalenones +; endothecial cells with base-plates, ektexine not tectate or columellate.

For phenylphenalenones, see Otálvaro et al. (2002), for the base plates of endothecial cells, see Manning (1996: absent in Commelinaceae, unknown for other families, sampling very poor).

HAEMODORACEAE R. Brown, nom. cons.   Back to Commelinales

Rhizomatous (cormose); fructans, chelidonic acid, flavones +; vessel elements in roots often with simple perforation plates, (vessels also in stem and leaf); leaves two-ranked, equitant and isobifacial, (margins [minutely] spiny); cyme [usu.] bifurcated, prophyll ± lateral; flowers (large), plane of symmetry transverse to oblique; (T tube +); A (connective appendages +); pollen with raphides; exine (1-)2(-3)-layered [no foot layer]; ovary inferior, placentae swollen; ovules 1-many/carpel, micropyle (exo)/endostomal, parietal tissue to 3 cells across, (nucellar cap +); cells of testa (and tegmen) variously elongated, ± thin-walled, operculum 0; chalazal endosperm haustorium +, embryo small/minute; ?collar rhizoids.

14[list]/116 - two subfamilies below. Tropics and warm temperate regions (map: from Heywood 1978 [Africa]; MacFarlane et al. 1987 [Australia]; Maas & Maas-van der Kamer 1993 [America]; Fl. N. Am. 26: 2002 [N. America]).

1. Haemodoroideae Arnott

(Bulbs), roots red; tannins 0; hairs with distinctive basal cells; flowers enantiostylous, tannin cells 0, usu. glabrous; A 3 [opposite inner P] (1 - Pyrorrhiza; staminodes +); ovary superior [secondarily]; seeds often flattened, pubescent or marginally winged; cotyledon not photosynthetic, hypocotyl at most short; n = 12, 15, 19-21.

8/39: Haemodorum (20). Tropics and warm temperate regions, not in southern South America, in Africa, only southern, in S.E. Asia not W. of Wallace's Line. [Photo - Flower, Fruit, Flower]

Synonymy: Dilatridaceae M. Roemer, Wachendorfiaceae Herbert, Xiphidiaceae Dumortier

2. Conostylidoideae Lindley

SiO₂ sand +; (epidermal walls thickened), hairs branched; flowers usu. pubescent; P connate or not, (pseudomonocyclic; valvate; monosymmetric); (A adnate to P); pollen 2-8 porate; (fruit indehiscent or a schizocarp); (seeds ridged, tegmen massive - Anigozanthus); cotyledon photosynthetic, hypocotyl +, primary root well developed; n = 4-8, 11.

6/80: Conostylis (50). S.W. Australia. [Photo - Flower]

Synonymy: Conostylidaceae Takhtajan

• Haemodoraceae may be recognised by their equitant and isobifacial leaves, their inflorescences, which are often rather elongated bifurcated helicoid cymes, their sometimes monosymmetric and/or enantiostylous flowers with inferior ovaries, and their roots, which in Haemodoroideae have a distinctive red color.

Evolution. Divergence & Distribution. Stem group Haemodoraceae are dated to ca 98 million years before present, divergence within the crown group to ca 81 million years before present (Janssen & Bremer 2004). Divergence within Haemodoroideae occurred in the early Eocene ca 47.9 million years ago, that within Conostyloideae later in the Eoceme ca 42 million years ago (Hopper et al. 2009). The restriction of Conostylidoideae to SW Australia is remarkable; Hopper et al. (2006) discuss the diversification of this group, in particular, that of Conostylis.

Plant-Animal Interactions. Seed-eating bugs of the Hemiptera-Lygaeidae-Blissinae are known from Haemodoraceae from South Africa; most bugs of this clade are sap-eaters (Slater 1976).

Chemistry, Morphology, etc. The median petal is abaxial in monosymmetric flowers of Haemodoroideae such as Wachendorfia, i.e., the flowers are inverted, while in Anigozanthus zygomorphy is evident as a slit down one side of a tube formed by the six connate tepals - the plane of symmetry must necessarily be slightly oblique here. However, as Eichler (1880) noted, if flowers are examined early in development, Wachendorfia has flowers with transverse symmetry, while in Anigozanthus they are oblique. Taxa like Xiphidium may have a more or less differentiated perianth with the two whorls each fully encircling the apex; the three stamens are borne opposite the petals/inner tepals. However, Anigozanthus clearly has six stamens individually opposite the six perianth lobes (see illustrations in Simpson 1990). There is clearly much variation in basic floral organization in this relatively small family.

The ovary may be secondarily superior (Simpson 1998a, b); the septal nectaries are found below the point of insertion of perianth. The outer periclinal wall of the testa is thick. Some additional information is taken from Simpson (1988, 1990); for variation in the pollen of Conostylis, see Pierce and Simpson (2009).

Phylogeny. For the phylogeny of the family, which has been quite extensively studied and integrated with anatomical and morphological variation, see Hopper et al. (1999) and Simpson et al. (2006); for the phylogeny of Conostylidoideae, see Hopper et al. (2006).

PONTEDERIACEAE Kunth, nom. cons.   Back to Commelinales

Water or marsh plants; vegetative stems indeterminate; (vessels also in stems); styloids or prismatic crystals 0 (+); stomatal subsidiary cells with oblique divisions; leaves spiral or spirally two-ranked (whorled), petiolate or not, 2ndaries transverse, sheath open or closed, often long-ligulate [= "stipules" sheathing to minute], colleters +; inflorescence subtended by two bracts; flowers open for one day, tristyly, enantiostyly, monosymmetry all common, obliquely monosymmetric [Pontederia cordata]; T ± undifferentiated, pseudomonocyclic, (large), deliquescent, (4, 3), mostly blue or yellow, ± connate, (tube to 11 cm long); A adnate to T, (1, 3, 4; staminodes 2), of different lengths, (tapetum secretory), filaments hairy; pollen 2- or 3-sulcate; (septal nectaries 0; placentation parietal; 1 carpel fertile), stigma small, dry; ovule (1/carpel), micropyle bistomal, parietal tissue absent (single layer - Monochoria), (epidermal cells ± radially elongated), postament +; (fruit an achene surrounded by P base); (seed ridged); exotestal cells box-like, endotestal cells elongated, tranversely flattened, operculum 0?; micropylar endosperm haustorium +, embryo long, suspensor hardly developed; n = (7) 8(-13); cotyledon linear, bifacial.

9[list]/33: Heteranthera (11). Tropics, also temperate, esp. New World (map: ; Fl. N. Am. 26: 2002). [Photos - Collection]

• Pontederiaceae are aquatic or marsh plants - sometimes annuals - with sheathing leaf bases that are often differentiated into a petiole and blade with many parallel veins, the blade of the younger leaf then encircles the petiole of the older leaf. The inflorescence has two bracts, either/both leaf-like and/or sheathing, and the marcescent, monosymmetric flowers are either basically blue or yellow.

Evolution. Divergence & Distribution. Stem group Pontederiaceae are dated to ca 89 million years before present, divergence within the crown group to ca 39 million years before present (Janssen & Bremer 2004).

Floral Biology & Seed Dispersal. Considerable work has been carried out on the floral biology of Pontederiaceae, where tristyly, enantiomorphy and monosymmetry (and Pontederia cordata, at least, is obliquely monosymmetric) are all well known. Graham and Barrett (1995) discussed the evolution of the breeding system, while Barrett and Graham (1997) outlined the phylogeny and diversification of the family and Kohn et al. (1996) the evolution of reproductive features, however, there have been problems with rooting the phylogenetic tree (see below, also Ness et al. 2011 and references). In the enantiostylous Monochoria there are five small stamens with yellow anthers and one large stamen with a blue anther (Wang et al. 1995 for pollination). Lunau (2006) suggests that the yellowish spot on the median-adaxial tepal member of some other Pontederiaceae mimics a stamen.

Chemistry, Morphology, etc. In Heteranthera, Eichornia s. str. and Pontederia s. str. (at least) the blade of the leaf of the axillary shoot completely encircle the main stem in bud, or the blade of the young leaf completely encircles the petiole of the next oldest leaf - this may be a unique arrangement (see also Eichler 1880) and so to be added to the apomorphies of the family. Although Hydrothrix gardneri appears to have whorled, linear leaves, only one leaf has a short, sheathing ligule; the others have narrower bases and are borne inside the sheath (Rutishauser 1999).

Information is taken from Coker (1907: seed anatomy), Ono (1928: ovule development), Tomlinson (1982: colleters), Tillich (1994: seedlings), Endress (1995b: flowers), Cook (1998: general) and Strange et al. (2004: floral anatomy).

Phylogeny. Eichornia currently is hopelessly paraphyletic, Pontederia and Monochoria being embedded in it (Graham et al. 1998; see also Ness et al. 2011). Simpson and Burton (2006) discuss the evolution of features of floral anatomy in the family, including outgroups; the embedded [Pontederia + Reussia] not only have single, apical ovules in the single fertile carpel and an achene surrounded by perianth, but they are the only members of the family to have styloids or prismatic crystals. Other features they studied also correlate with the clades evident in the phylogenetic analyses of Barrett and Graham (1997). There have been persistent problems in rooting the tree (also Graham et al. 1998, esp. 2002), but a recent study suggests that Eichornea meyeri is sister to the rest of the family - although there are still some lingering doubts (Ness et al. 2011).

Synonymy: Heterantheraceae J. Agardh