EXTANT SEED PLANTS

Plant woody, evergreen; nicotinic acid metabolised to trigonelline; primary cell walls rich in xyloglucans and/or glucomannans, 25-30% pectin [Type I walls]; lignins rich in guaiacyl units; true roots present, xylem exarch; shoot apical meristem complex; arbuscular mycorrhizae +; stem with ectophloic eustele, endodermis 0, xylem endarch; vascular tissue in t.s. discontinuous by interfascicular regions; vascular cambium + [xylem ("wood") differentiating internally, phloem externally]; wood homoxylous, tracheids +; tracheid/tracheid pits circular, bordered; sieve tube/cell plastids with starch grains; phloem fibers +; stem cork cambium superficial, root cork cambium deep seated; nodes ?; leaf vascular bundles collateral; leaves spiral, simple, axillary buds?, prophylls [including bracteoles] two, lateral; plant heterosporous, sporangia eusporangiate, on sporophylls, sporophylls aggregated in indeterminate cones/strobili; true pollen [microspores] +, mono[ana]sulcate, pollen exine and intine homogeneous, ovules unitegmic, crassinucellate, megaspore tetrad tetrahedral, only one megaspore develops, megasporangium indehiscent; male gametophyte development endo/exosporic, gametes two, with cell walls; 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 duplication, mitochondrial nad1 intron 2 and coxIIi3 intron present.

MAGNOLIOPHYTA

Plant woody, evergreen; lignans, O-methyl flavonols, dihydroflavonols, triterpenoid oleanane, 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, syringyl:guaiacyl ratio less 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; stem with 2-layered tunica-corpus construction; wood fibers and wood parenchyma +; 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 tube, the sieve tube with P-proteins; nodes unilacunar; stomata with ends of guard cells level with aperture, 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, 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, pollen subspherical, binucleate at dispersal, trinucleate eventually, tectum continuous, endexine compact, lamellate only in the apertural regions, pollen tube elongated, with callose plugs, penetrating between cells, growth rate moderate, siphonogamy occuring, nectary 0, G free, several, ascidiate, with postgenital occlusion by secretion, few [?1] ovules/carpel, ovules marginal, anatropous, bitegmic, micropyle endostomal, integuments 2-3 cells thick, megasporocyte single, megaspore lacking sporopollenin and cuticle, chalazal, female gametophyte ?type, stylulus 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; germination hypogeal, seedlings/young plants sympodial; Arabidopsis-type telomeres [(TTTAGGG)_n]; whole genome duplication, 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 PHYA/PHYC gene pairs.

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 [[CHLORANTHALES + MAGNOLIIDS] [MONOCOTS [CERATOPHYLLALES + EUDICOTS]]]]: vessels +, elements with scalariform perforation plates; pollen tectate-columellate, tectum reticulate [perforated]; nucleus of egg cell sister to one of the polar nuclei; ?genome duplication; "DEAER" motif in AP3 and PI genes lost, gaps in these genes.

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

POALES + COMMELINALES + ZINGIBERALES: Primary cell wall mostly with glucurono-arabinoxylans; stomata paracytic or tetracytic with parallel cell divisions [parallelocytic]; endosperm starchy.

COMMELINALES + ZINGIBERALES: inflorescences indeterminate, but with many-flowered cincinnal [helicoid cyme] branches; tapetum invasive or plasmodial.

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 and in Kress and Specht (2006) they are ca 124 and 110-80 million years before present.

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 Graham et al. (2006) and Chase et al. (2006). Tapetal variation in those few Zingiberales studied is extensive (Prakash et al. 2000; Furness & Rudall 2001; Simão et al. 2007). There are several kinds of monosymmetry, especially in Zingiberales.

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

ZINGIBERALES Grisebach  Main Tree, Synapomorphies.

No aerial stem except when flowering; SiO₂ in bundle sheath; sieve tube plastids also with starch grains; petiole bundles in arcs; guard cells symmetrical; cuticular waxes as aggregated rodlets; leaves with distinct petiole, midrib, S-shaped lateral veins and fine cross venation; inflorescence bracts large, persistent; flowers large, monosymmetric, P = colored K surrounding C, A 5, adaxial member of inner whorl not developed, anthers long, pollen inaperturate, exine thin and spinulose to 0 [pollen not resistant to acetolysis], G inferior, outer integument 3< cells across, micropyle bistomal, parietal cells 1 (2) layer thick, nucellar pad + [radially elongated epidermal cells of nucellus], style long, stigma large, wet; fruit capsular; seeds arillate, operculate, operculum testal, micropylar collar + [develops from outer integument and forms annular inpushing in perisperm surrounding operculum], endotesta sclerotised and silicified; endosperm nuclear, perisperm s.l. +, starchy, embryo plug-like; cotyledon not photosynthetic, ligulate, collar roots +; six nucleotide deletion in atpA. - 8 families, 92 genera, 2111 species.

Stem-group Zingiberales are dated to ca 114 million years before present, divergence within the group to ca 88 million years before present (Janssen & Bremer 2004); comparable figures are 84 and 62 million years before present in Bremer (2000b) and 81-73 and 62-38 million years before present in Wikström et al. (2001). However, Kress and Specht (2005) find stem group dates possibly as early as 158 million years before present (127-121 million years before present in Kress & Specht 2006), crown group divergence began ca 95 million years before present (144-106 million years before present: see Kress & Specht 2005, 2006 for extensive if somewhat differing details of divergence dates in Zingiberales; families other than Cannaceae and Marantaceae had all diverged by ca 60 million years before present [all families had diverged by 86-74 million years before present - Kress & Specht 2006]). Janssen and Bremer (2004) found divergence dates within Zingiberales to show a similarly wide spread (ages estimated under the DELTRAN optimisation were notably younger than those estimated under the two other regimes used). The unplaced (other than to order) Spirematospermum is known fossil from the Late Cretaceous.

Zingiberales are giant herbs with often rather complex monosymmetric flowers that are largely restricted to the tropics. Givnish et al. (2005, 2006b) note that acquisition of net venation and animal-dispersed propagules and tolerance of shady habitats are linked in this group. McKenna and Farrell (2005, 2006) discuss the diversification of the chrysomelid beetle Cephaloleia on Zingiberales (they also occur on other commelinids, also on Cyclanthaceae: see also Staines 2004). Both feeding on Zingiberales and specialisation of the larvae and particularly adults on the young, rolled leaves may each have evolved once; the association between the beetles and Zingiberales may date from the very late Cretaceous (Wilf et al. 2000; McKenna & Farrell 2006). Euglossine bees are important pollinators of neotropical Zingiberales (Zucchi et al. 1969; Williams 1982).

The phenol zingerone (C₁₁H₁₄O₃) has apparently been isolated from Eocene fossils of the unplaced (other than to order) Spirematospermum; is its presence a synapomorphy for the family (van Bergen & Collinson 1999)? The roots tend to have V-shaped aggregations of xylem, with an especially large metaxylem element at the angle (von Guttenberg 1968). Arber (1925) suggests that the cauline vascular bundles are not amphivasal, but I have not checked this against recent anatomical literature. Zingiberales seem particularly commonly to lack vessels in the stem and especially the leaves. When the perianth is differentiated into two whorls, both are more or less petalline. The stamens are opposite individual perianth members in Strelitzia, Lowia; Heliconiaceae and Musaceae (see also Payer 1857); there seem to be several vascular bundles in the massive stamens of Musaceae and Zingiberaceae, at least. Although pollen grains of the order are apparently inaperturate, there is variation in whether or not they are functionally monoaperturate or omniaperturate (Kress 1986; Furness & Rudall 2000b).

The phylogeny of the order has been much studied, but many relationships are still somewhat unclear - see especially Kress (1990b, 1995) and Kress et al. (2001: the tree here [conservative!] is based on their 2 gene + morphology successive approximations tree), also Wikström et al. (2001: three genes, Musaceae [Heliconiacaeae [[Lowiaceae + Strelitziaceae] [the rest]]]), Andersson and Chase (2001: Costaceae and Zingiberaceae are not obviously sister taxa) and Janssen and Bremer (2004). Musaceae are weakly (barely over 50%) supported as sister to the rest of the order in Kress et al. (2001), and slightly better, but still not that well (78%) supported as member of a clade [[Lowiaceae + Strelitziaceae], Heliconiaceae, Musaceae] in Givnish et al. (2006b: one gene). Even the relationships [[Costaceae + Zingiberaceae] [Marantaceae + Cannaceae]] are not found in some analyses (e.g. Davis et al. 2004, but general support values very low; Soltis et al. 2007a). Johansen (2005), looking at six DNA regions (plastid, nuclear), recently suggested that Lowiaceae and Strelitziaceae were successively sister to remaining Zingiberales, which would make reconstruction of character evolution of the flowers in particular ambiguous; however, support was not strong and sampling other than in Orchidanthera, the focus of the paper, was poor. Hence the conservative and rather minimal resolution of relationships in the tree here.

For an early but still interesting general discussion on evolutionary morphology of the order, see Tomlinson (1961), for information on anatomy, see Tomlinson (1969), on seed morphology, see Grootjen and Bouman (1981), Manchester and Kress (1993), and Liao et al. (2004), on nectary and nectary duct morphology and position, see Kirchoff (1992), for sieve tube inclusions, etc., see Behnke (1994b: Zingiberaceae-Tamijioideae and - Siphonochiloideae?), on general floral morphology, see Endress (1994b), on tapetum, see Furness and Rudall (2001), on the atpA deletion, see Davis et al. (2004), for phenylphenalenones, see Otálvaro et al. (2002), on chromosome numbers, with suggestions as to the plesiomorphic number for the order, see Song et al. (2004), for phytoliths, see Piperno (2006), and for a detailed classification of the order, see Kress et al. (2001).

Includes Cannaceae, Costaceae, Heliconiaceae, Lowiaceae, Marantaceae, Musaceae, Strelitziaceae, Zingiberaceae.

Synonymy: Cannales Dumortier, Lowiales Reveal & Doweld, Musales Reveal - Zingiberanae Reveal - Zingiberidae Cronquist

MUSACEAE Jussieu, nom. cons.   Back to Zingiberales

Plant cormose; (phenylphenalenones +); SiO₂ bodies deorated and trough-shaped; hairs 0; rhizome with endodermis; roots with scattered wide vessels and strands of phloem in the pith; vessels also in stem; articulated laticifers +; mucilage cells +; petiole with 1 series of ± abaxial air canals; prophylls lateral; leaves spiral, petiole short, axillary buds 0 or leaf-opposed; plant monoecious; inflorescence bracts deciduous, floral bracts bracteoles 0; P = T, connate except adaxially, pseudomonocyclic, adaxial inner T free, reduced and ± cucullate, staminate flowers: (A 6), tapetum glandular, staminode 0; carpellate flowers: intra-ovarian trichomes +, (micropyle exostomal), outer integument massive, inner integument 2-layered, hypostase +, stigma capitate; fruit a berry; seed with chalazal chamber, micropylar collar well developed, aril?, exotesta siliceous, mesotesta massive, 20-25 cells across, sclerotised; n = (7) 9 (11); collar at right angles to cotyledon.

2[list]/35. Africa, Himalayas to South East Asia, Philippines and N. Australia (Map: J. Kress, pers. comm.). [Photos - Collection]

• Musaceae are large herbs with spiral, shortly-petiolate leaves in which the secondary veins depart more or less at right angles from the midrib. The inflorescence bracts are usually deciduous and subtend fascicles of ebracteate flowers. The monosymmetric flowers have five tepals connate except adaxially, where there is a single, free, deeply concave tepal.

Stem-group Musaceae are dated to ca 87 million years before present, divergence within the crown group to ca 61 million years before present (Janssen & Bremer 2004). Musaceae are known fossil in the Eocene of W. North America (Manchester & Kress 1993).

The tegmen is two cells layers across; the cells are elongate. Does the endosperm have a small chalazal chamber? The mitochondria, but not the chloroplasts, are paternally inherited in Musa (Fauré et al. 1994).

Some information is taken from Tomlinson (1959: anatomy), Andersson (1998: general), Graven et al. (1996: seed) and Xue et al. (2007: embryology of Musella); see Piperno (2006) for phytoliths and domestication.

HELICONIACEAE Nakai   Back to Zingiberales

Rhizome with endodermoid layer; SiO₂ bodies decorated and trough-shaped; stomata polycytic, neighbouring cells with oblique divisions; petiole long; P = T, median outer T adaxial, 5 connate, median outer T ± free, A 5, basally adnate to T, pollen functionally monoaperturate, adaxial outer A staminodial, scale-like, tapetum amoeboid, non-syncytical, 1 basal apotropous ovule/carpel, micropyle bistomal, style hollow; fruit a fleshy schizocarp or drupe; aril 0, testa and tegmen thin, undifferentiated, operculum derived from funicle; n = (11) 12; coleoptile 0, but sheath lobed, collar at right angles to cotyledon.

1[list]/100-200. Mostly tropical America, a few Celebes to the Pacific (Map: Old World from Kress 1990a; New World, J. Kress, pers. comm.). [Photo - Flower, Flower.]

• Heliconiaceae are large herbs with 2-ranked leaves and inflorescences with large, colored bracts in the axils of which are fascicles of flowers with petaloid tepals; the drupaceous fruit is borne on a stout, elongated pedicel and has a single hard stone per loculus.

Heliconiaceae diverged from other Zingiberales 114-104 million years before present (Kress & Specht 2006) or ca 88 million years before present (Janssen & Bremer 2004); divergence of crown group Heliconia occured 43-21 million years before present (Kress & Specht 2006) or ca 32 million years before present (McKenna & Farrell 2006). Variation in floral and especially inflorescence morphology is considerable (Berry and Kress 1991). Water may collect in the floral bracts of species with erect inflorescences, the corolla and later a thick and fleshy pedicel elongating, the first to raise the flower and the second to raise the fruits above the surface of the water. Bird pollination is prevalent, and Heliconia is a resource for sickle-bill humming birds (Eutoxeres) at lower altitudes; at higher altitudes in the Andes Centropogon (Lobelioideae) takes over (Stiles 1975; Stein 1992). Pollen-connecting threads derived from the break-down of cell walls are found in the family (Rose & Barthlott 1995; Simão et al. 2007). The herbivorous Cephaloleia beetles (Cassidinae, Chrysomelidae) seem to have diversified in the Oligocene coincident with crown Heliconia diversification (McKenna & Farrel 2006).

Rudall and Bateman (2004) note that flowers in which the abaxial stamen of the outer whorl is sterile is a feature of Heliconiaceae plus the Marantaceae-Zingiberaceae clade, however, Heliconiaceae are sister to all other Zingiberales in the phylogeny of Janssen and Bremer (2004). The parietal layer is one cell thick and disintegrates.

Some information is taken from Tomlinson (1959: anatomy), Kirchoff (1992) and Andersson (1998); Simão et al. (2006) provide information about ovule and seed.

Strelitziaceae + Lowiaceae: petiole with adaxial and abaxial series of air canals; P = petalline K + C, A individually opposite the P members, adaxial A of inner whorl sterile, tapetum glandular [inc. Lowiaceae?], floral column [sterile apex of ovary] +, stigma 3-lobed; aril hairy.

This clade diverges from other Zingiberales 112-106 million years before present (Kress & Specht 2006) or ca 83 million years before present (Janssen & Bremer 2004).

The exostomal aril is lobed or fimbriate.

For details of anatomy, see Tomlinson (1959: anatomy), and of the floral column, the result of intercalary growth at the top of the ovary, see Kirchoff and Kunze (1995).

STRELITZIACEAE Hutchinson, nom. cons.   Back to Zingiberales

Arborescent or rhizomatous; phenylphenalenones +; SiO₂ bodies ± spherical; roots with scattered wide vessels and strands of phloem in the pith; petiole long, with several arcs of air canals; stomata polycytic (cell divisions oblique); C basally connate (2 lateral connate), adaxial smaller (± cucullate), (A 6 - Ravenala), tapetum glandular, micropyle bistomal, stigma long-turbinate; capsule woody; micropylar collar 0, operculum rudimentary, tegmen only a cuticle; (perisperm 0); n = (7) 11; primary root well developed.

3[list]/7. Tropical South America, E. southern Africa, Madagascar (Map: J. Kress, pers. comm.). [Photo - Flower]

• Strelitziaceae can be recognised by their 2-ranked, long-petiolate leaves and inflorescences with tough, boat-shaped, green inflorescence bracts. The distinctive flowers have more or less connate lateral abaxial petals, and the woody capsules have seeds with brightly colored, fimbriate arils.

Stem-group Strelitziaceae are dated to ca 78 million years before present, divergence within the crown group to ca 59 million years before present (Janssen & Bremer 2004). Pollination in the group has been much studied, although it is unclear what the plesiomorphic condition might be (cf. Kress et al. 1994).

The rhizomes of Strelitzia reginae branch dichotomously. Thread-like structures are found in the anthers of Strelitzia; these are formed from rows of epidermal cells (Kronestedt & Bystedt 1981).

Some information is taken from Andersson (1998); he suggested that staminodes were absent.

LOWIACEAE Ridley, nom. cons.   Back to Zingiberales

SiO₂ bodies ± conical; endodermoid layer in rhizome; guard cells aymmetrical [with inner and outer ledges unequal]; cross veins in abaxial part of lamina; petiole long; inflorescence complex [repeating 1-flowered units, branching from bracts below the flower, the flower axillary]; flowers held upside down, K basally connate, adaxial C large, labellar, abaxial pair small, enclosing A, A basally adnate to C, (staminode +), nectary 0, outer integument 14-16 layers and inner integument ca 4 layers across, stigma monosymmetric, dorsiventrally flattened, secretory tissue [viscidium] on adaxial side at base, lobes ± fimbriate; seed hairy, micropylar collar?, testa vascularized, exotesta and next two layers lignified, endotesta of radially elongated sclereids; perisperm slight; n = 9; seedling?

1[list]/15. S. China to Borneo (Map: J. Kress, pers. comm.). [Photo - Orchidantha Flower © M. Bordelon]

• The leaves of Lowiaceae have steeply ascending and apparently rather distant longitudinal veins (some are much more prominent than the others) and strongly developed cross veins that are more evident on the abaxial than the adaxial surface. The flowers are held with the median sepal adaxial, the median petal forms a well-developed abaxial labellum, and the two lateral petals are small.

Lowiaceae diverge from other Zingiberales ca 78 million years before present (Janssen & Bremer 2004).

The flowers last one day, and are often held in an inverted position, the median sepal being adaxial and the median petal forming a labellum. The longitudinal and horizontal vascular bundles of the leaf blades can appear almost independant in cross section. The stamens are opposite both calyx and corolla separately (Kirchoff & Kunze 1995). The family is very poorly known; it is not clear if the endotesta is silicified.

Much information is taken from Larsen (1998); see also Wen et al. (1997: seed), Pedersen (2001: general), and Pedersen and Johansen (2004: flowers); see Johansen (2005) for phylogeny.

[Cannaceae + Marantaceae] [Costaceae + Zingiberaceae]: SiO₂ bodies decorated [druse-shaped] and with troughs; raphides 0; petiole with one series of air canals; guard cells asymmetrical [with inner and outer ledges unequal]; petiole short, poorly differentiated; K = petalline K + C, C connate, both A whorls with two staminodes, adaxial A of inner whorl fertile, tapetum amoeboid, non-syncytial, micropyle endostomal, collar well developed, cells of exotesta longitudinally elongated; chalazosperm [perisperm of some authors] +, endosperm slight.

The two clades in this group diverged ca 84 million years before present, very shortly after the whole clade separated from other Zingiberales (Janssen & Bremer 2004); a similar sequence of events, but occuring rather earlier, is suggested by Kress and Specht (2006): the group diverged from Heliconiaceae 114-104 million years before present, while the two clades separated 110-102 million years before present.

Costus, Canna and Kaempferia and at least some other genera have more or less lateral prophylls...(e.g. Rüter 1918). It is unclear exactly what staminodes may have been present in the common ancestor of this group. Zingiberaceae and Cannaceae, at least, have placentoids (Weberling 1989).

Some information on seed anatomy is taken from Tang et al. (2005); there is no mention of starch in the endosperm. Judd et al. (2007) provide useful information.

Cannaceae + Marantaceae: oblique cells in petiole; flowers asymmetrical; A ½, staminodes free, stigma not notably expanded; endosperm absent or almost so.

The Cannaceae and Marantaceae clades diverged 101-91 million years before present (Kress & Specht 2006) or ca 68 million years before present (Janssen & Bremer 2004).

CANNACEAE Jussieu, nom. cons.   Back to Zingiberales

Chelidonic acid, aromatic resin +; SiO₂ bodies ± druse-like; mucilage canals in stem; guard cells with inner and outer ledges ± equal; (leaves spiral); inflorescence branched; flower short-lived, staminodes 1-4(-5), tapetal cells 2-6-nucleate, microsporogenesis also successive, style flattened, pollen deposited abaxially, stigma on one side; capsule glandular-muricate; seed pachychalazal, aril funicular, imbibition lid on raphe, operculum 0, exotesta and epidermis of chalaza a malpighian layer, mesotesta sclereidal, endotesta 0; n = 9; primary root well developed.

1[list]/19. New World (sub)tropics (Map: J. Kress, pers. comm.). [Photo - Flower]

• Cannaceae are large herbs with shortly-petiolate leaves; their flowers are large, short-lived, and asymmetrical and have a flattened style and a softly spiny [muricate] inferior ovary and fruit.

Pollen is deposited on the abaxial surface of the flattened style whence it is picked up by the pollinator. 600-year-old seeds of Canna compacta may still be able to germinate.

Floral diagrams in Eichler (1875) suggest that the prophyll is lateral and the plane of symmetry of the flower inverted. Grootjen and Bouman (1988) described a pachychalaza in Cannaceae, with mitosis occuring during ovule development in the chalaza and basal part of the nucellus. This is unlike the other Zingiberalean families. The arils is often described as being absent (e.g. Grootjen & Bouman 1981), and the funicular aril mentioned above is unlike that of other Zingiberales.

Information is taken from Tomlinson (1961b: anatomy), Kubitzki (1998d: general) and Tanaka (2001: revision).

MARANTACEAE R. Brown, nom. cons.   Back to Zingiberales

Aerial stem +/0, rhizome fibrous or woody; (mucilage canals - Thalia); SiO₂ bodies hat- or druse-like; leaf sheath closed; petiole distinct, often long, pulvinate at the apex [oblique cells]; (inflorescence branched; bracts deciduous); flowers moderately-sized, in mirror image pairs [2-flowered cymules]; C A and style all basally fused, (outer staminodes 0), one inner staminode cucullate, another ± fleshy and with callosities, fertile half stamen often with a petaloid lateral appendage, 1 basal ovule/carpel, only 1 G fertile, ovules becoming amphitropous, (micropyle bistomal - Phrynium), style under tension, becoming curved, pollen deposited on adaxial surface [on "stamp", with secretory area]; (fruit indehiscent); mesotesta tanniniferous, operculum endotestal, (tegmen with thin elongated sclereids), chalaza penetrates into nucellus, eventually cells die; embryo curved, long; n = 9-13; (mesocotyl +), collar at right angles to cotyledon.

31[list]/550: Calathea (300). Tropics, esp. American, not in Australia (Map: from Heywood 1978; Andrew Ford, pers. comm.; Fl. N. Am. 4: 2003). [Photo - Leaf, Flower.]

• Marantaceae are often robust herbs that may be recognised by their pulvinate, petiolate leaves and paired, often only moderately-sized, asymmetrical flowers.

Divergence within the crown group is dated to 70-58 million years before present (Kress & Specht 2006) or ca 57 million years before present (Janssen & Bremer 2004). The family may be African in origin (Andersson & Chase 2001). Marantaceae are noted for their complex, enantiostylous, asymmetrical flowers that have an explosive pollination device. The style is held under tension by a cucullate inner staminode (the staminodium cucullatum), while the other inner staminode (the staminodium callosum) is firm and fleshy, with knobs, etc., on its adaxial surface. Sticky pollen is deposited on the flattened stamp on the adaxial surface of the style by the early-maturing anther while the flower is still in bud, and there is an adjacent secretory area. The progress of the pollinator in the flower is guided by the knobs, etc., of the firm staminode, and the flower is actually tripped by the pollinator when it comes into contact with an appendage on the cucullate staminode. The style then abruptly curves and pollen from that flower is deposited on the pollinator from the stamp aided by the secretions of the adjacent secretory area, and pollen from another flower deposited on the stigma itself, which is depressed. In the New World in particular, long-tongued, trap-lining euglossine bees are the main pollinating agents, and the floral tube lengths of New World Marantaceae are appreciably longer than their Old World representatives, ca 17.6 mm long versus ca 4.6 mm long (see Kennedy 2000 for general information on pollination, also Andersson 1998).

The plant is made up of repeating units with prophyll, reduced leaf (both with short internodes), and then leaves varying in number and internode length, although the first is often longest - and also orientation, since the plane of distichy may be at right angles to that of the parent axis - and terminal complex inflorescence (Tomlinson 1961a).

The current classification hardly reflects what is known about phlyogeny, and Prince and Kress (2006a) suggest that five informal groups be recognized, the Sarcophrynium, Stachyphrynium, Maranta, Donax and Calathea clades. However, note that relationships between these clades is for the most part unclear (very low bootstrap vales, mostly high posterior probabilities alone), and support for these five informal groups other than the Stachyphrynium and Maranta groups (also well supported as sister taxa) is little better (Prince & Kress 2006b: eight genes, all three compartments!). Andersson and Chase (2001) provide a phylogenetic classification of the family.

Some information is taken from Andersson (1981, 1998: general), who questioned the chromosome numbers reported for the family because of the small size of the chromosomes, problems with the identity of the material counted, etc. For morpology and anatomy, see Tomlinson (1961a), for inflorescence structure, see Andersson (1976), for seed morphology, see Grootjen (1983), for phylogeny, see Prince and Kress (2006a, b).

Costaceae + Zingiberaceae: leaf ligulate; K connate, labellum from lateral staminodes of outer whorl and from the 2 staminodes of inner whorl, large, with narrow tube and distinct open limb, A 1, exine +, style slender, running between two half anthers, nectaries 2, on top of ovary, stigma cup- or funnel-shaped; chalazal mass in seed ± developed, endosperm helobial, persistent, not that copious; hypocotyl well developed.

These two families diverged 109-101 million years before present (Kress & Specht 2006) or ca 79 million years before present (Janssen & Bremer 2004).

For possible additional floral synapomorphies, see Specht et al. (2001), for floral development, see Kirchoff (1988). The massive stamens of Costus, at least, have several vascular bundles in the region of the anthers.

COSTACEAE Nakai   Back to Zingiberales

Aerial stem +, (branched); benzoquinones, steroidal saponins +; sheath with 1 series of adaxial air canals, no canals in petiole and lamina, vascular bundles adaxial; hypodermis 1< layered; (hairs multicellular); leaves spiromonostichous, sheath closed; inflorescence spicate-capitate, (flowers/inflorescence axillary), bracts often with abaxial nectaries; abaxial member of outer A whorl staminodial, all 5 staminodes connate, pollen aperturate, exine +, (G [2]), outer integument ca 5 cells thick, nucellar epidermal cells elongated vertically, stylar canal +, stigma also bilamellate, fimbriate; endosperm without starch; n = 9 (14); cotyledon blade-like, photosynthetic, with apical backwardly-directed process.

6[list]/110: Costus (90). Pantropical, esp. America and Papuasia-Australia (Map: Maas 1972). [Photo - Costus © L. Brothers, Dimerocostus © L. Brothers.]

• Costaceae can be recognised even vegetatively: they have ligulate leaves with a closed sheath that are arranged in a single spiral up the stem. Their inflorescences are dense, spicate-capitate, and have large bracts, and their monosymmetric flowers have a large labellum and single stamen, the style running between the two halves of the large anther.

Divergence within crown group Costaceae can be dated to ca 47 million years before present (Janssen & Bremer 2004) or 73-58 million years before present (Specht 2005, 2006). Specht (2006) discusses the diversification and biogeography of the family in detail, while Specht (2005) focused on floral evolution and pollination (see also Kay et al. 2005; Kay & Schemske 2003); hummingbird pollination seems to have been particularly important in facilitating diversification of neotropical Costus, but euglossine bees are also pollinators. There are often extrafloral nectaries on the inflorescence bracts.

Specht (2006) provides a detailed phylogeny on which a generic revision (Specht & Kress 2006) is based (Specht et al. 2001 also outline the phylogeny); a number of morphological characters can be used to characterise these genera.

The pollen is particularly variable, being disulcate, porate, pantoporate or spiraperturate; the grains are resistant to acetolysis. The endosperm is oily. There are two to four rows of ovules (Newman & Kirchoff 1992).

Some information is taken from Larsen (1998: general) and Grootjen and Bouman (1981: ovule and seed development).

ZINGIBERACEAE Martynov, nom. cons.   Back to Zingiberales

Phenylpropanoids and related curcumins, ethereal oils +; SiO₂ usu. as sand; (vessels also in stem); sieve elements with nuclear non-dispersive crystalline protein bodies; oil cells +; (hairs with sunken bases); plane of distichy parallel to the rhizome, (leaf sheath closed); vascular bundles in leaf axis abaxial; hypodermis 0-1-layered; inflorescence branched; (inflorescence bracts deciduous), bracteoles obliquely adaxial or lateral; median A of outer whorl 0, (1-)many ovules/carpel, nucellar cap +, hypostase common, style hollow; capsule fleshy; exotesta of fibriform cells; chalazosperm 0; n = 8-14+; collar not prominent.

46-52[list]/1075-1300 - four groups below. (Sub)tropical, esp. South East Asia-Malesia (Map: from Maas 1977; Heywood 2007). [Photo - Fruit]

1. Siphonochiloideae W. J. Kress

Rhizome fleshy, vertical; inflorescence a raceme, bracteoles 0.

1/15. Africa and Madagascar.

2. Tamijioideae W. J. Kress

Rhizome fibrous; placentation parietal; fruit?

1/1: Tamijia flagellaris. Borneo.

For additional information, see Sakai and Nagamasu (2000).

Alpinioideae + Zingiberoideae: labellum formed by the two staminodes of the inner whorl alone; endosperm without starch.

3. Alpinioideae Link

Rhizome fleshy, plane of distichy parallel to the ground [position where?]; (styloids + - Aframomum); (lamina with nectary pits on abaxial midrib of lamina - Riedelieae); lateral staminodes of outer whorl very small or 0; (fruit indehiscent - some Alpinieae; opening by longitudinal slits - Riedelieae).

Alpinia (200), Amomum (150: polyphyletic), Renealmia (75: see Särkinen et al. 2007 for a phylogeny, migration from Africa to America within the last 16 million years), Etlingera (70), Riedelia (60), Aframomum (50), Hornstedia (50). Indo-Malesia, tropical Australia; Renealmia, American and African tropics.

Pommereschea has a parenchymatous endotesta (Liao & Wu 2000) and also a long style - it is somewhat odd in Alpinieae. Generic limits need attention (e.g. Xia et al. 2004; Kress et al. 2007).

For the phylogeny of part of Alpinioideae, see Pedersen (2004), especially Kress et al. (2005: Alpinia strongly para/polyphyletic). Flexistyly (the style changing its orientation during anthesis) is scattered through the subfamily (Kress et al. 2005, and references).

Synonymy: Alpiniaceae Rudolphi, Amomaceae Jaume Saint-Hilaire

4. Zingiberoideae Hasskarl

Rhizomes fibrous, plane of distichy at right angles to the ground; (steroidal saponins + - Hedychium); (lateral staminodes of outer whorl ± well developed; free from labellum), (labellum adnate to filament and forming tube [Globbeae]), (tapetum amoeboid; pollen sulcate - Zingiber), (placentation basal; parietal - Globbeae); (seed carunculate - Globba, Zingiber); (multilayered exotestal epidermis - Globbeae), endotesta parenchymatous; starch grains of perisperm compound (simple - Globbeae), embryo long [Hedychium].

Globba (100), Zingiber (100), Boesenbergia (60), Hedychium (50). Indo-Malesia, tropical Australia.

Globba and Hedychium and relatives lack U-shaped cells in the endotesta.

For Zingiber, the spice ginger, etc., see Ravinandran and Babu (2005).

Synonymy: Curcumaceae Dumortier

• Zingiberaceae are usually large and often aromatic rhizomatous herbs with 2-ranked leaves that have open sheaths; an inflorescence that is frequently branched; and pedicellate, monosymmetric flowers with a single stamen, the style running between the two halves of the large anther.

Stem-group Zingiberaceae are dated to ca 79 million years before present, divergence within the crown group to ca 26 million years before present (Janssen & Bremer 2004: Tamijia amd Siphonochilus not included).

Although Larsen et al. (1998) suggest that Hedychieae lack an operculum in the seed, Grootjen and Bouman (1981) report one from Hedychium itself. Ellettaria has an embryo almost as long as the seed.

Relationships in the family are [Siphonochiloideae [Tamijioideae [Alpinioideae + Zingiberoideae]]] - all clades with strong support (Kress et al. 2002: two genes). Ngamriabsakul et al. (2004) discuss relationships within Zingibereae, and for a phylogeny of Globbeae, see Williams (2003).

Some information is taken from Tomlinson (1956: anatomy), Larsen et al. (1998: general), and Wood et al. (2000: Hedychium and relatives).