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 Commelinales 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.

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, T brightly colored; A 5, immediately adjacent to T members, adaxial member of inner whorl not developed; anthers long; pollen inaperturate, exine thin and spinulose to 0 [pollen not resistant to acetolysis]; G inferior, (septal nectaries labyrinthine), style long, stigma large, wet; ovule with outer integument 5< cells across, epidermal cells of nucellus apex radially elongated [nucellar pad], suprachalazal tissue well developed; fruit capsular; seeds arillate, operculate; operculum testal, micropylar collar developing from outer integument, forming annular inpushing in perisperm surrounding operculum, endotesta sclerotised and silicified, thickening often U-shaped in t.s.; endosperm nuclear, perisperm s.l. +, reserves starchy, embryo plug-like; cotyledon not photosynthetic, ligulate, collar roots +; six nucleotide deletion in atpA. - 8 families, 92 genera, 2111 species.

• Zingiberales are usually giant herbs with petiolate leaves and often quite large and rather complex monosymmetric flowers. Members of this group are largely restricted to the tropics.

Evolution. Divergence & Distribution. Stem-group Zingiberales are dated to ca 114 million years before present, crwon-group divergence 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); these latter dates are compatible with the idea that there was rapid radiation of Zingiberales in the early Tertiary some 65 million years ago (see also Christelova et al. 2011). 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). Magallón and Castillo (2009) estimate ca 110 and 99 and 87 and 79.5 million years for relaxed and constrained penalized likelihood datings for stem and crown group Zingiberales respectively. It is difficult to think about the evolution of the clade with such a spread of estimates! The distinctive seeds of the unplaced (other than to order) Spirematospermum are known from the Late Cretaceous (see also Collinson & van Bergen 2004 for fossils).

Endress (2011a) thought that the inferior ovary found in all taxa of this clade might be a key innovation.

Ecology. 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.

Plant-Animal Interactions. 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).

Floral Biology. Understanding floral evolution in Zingiberales is difficult, and not only because of uncertainty about the phylogeny. When the perianth is differentiated into two whorls, both are more or less petal-like, although the inner is larger, and the stamens are inside this inner whorl, however, the stamens are opposite individual perianth members of both whorls in Strelitzia, Lowia, Heliconiaceae and Musaceae (see also Payer 1857). Bracteoles are more or less lateral in Canna, Costus, Heliconia, etc., and flowers of the first seem to have inverted orientation (see also Heliconia below). The flowers of Marantaceae may have an oblique plane of symmetry (but of course they are also strongly enantiomorphic), while there is also variation in the stage at which monosymmetry is evident in the flower (see also Kunze 1985; Kirchoff 2003; Kunze et al. 2005c). Interestingly, the short, broad concave staminodes of Heliconia and inner adaxial tepal/petal of Musa and Strelitzia may look quite similar. There has been a triplication of the CYC-like gene in the clade (Bartlett & Specht 2009, 2011) as well as duplications of GLOBOSA-like genes (Bartlett & Specht 2010) that are perhaps involved in floral diversification and the evolution of monosymmetry.

Animal pollination pervades the order, and bird pollination in particular is perhaps notably common (Cronk & Ojeda 2008). However, euglossine bees are also important pollinators of neotropical Zingiberales (Zucchi et al. 1969; Williams 1982), and they began diversifying some 42-27 million years ago (Ramírez et al. 2010).

Genes & Genomes. Mahanty (1970) and Song et al. (2004) suggest that the base chromosome number for the order (x) = 11.

Chemistry, Morphology, etc. 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 order (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.

Koen (2006) noted that Musa and Calathea ornata were unusual in that in all the individuals of these two species that he examined the genetic spiral proceeded in the same direction, although in other plants clockwise and counter-clockwise spirals occured in equal frequencies. In plants of Musaceae, Heliconiaceae and Strelitziaceae, at least, growing in more or less open conditions, the leaves tear along the veins producing a kind of compound leaf (cf. Arecaceae). 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).

For an early but still interesting general discussion on evolutionary morphology of the order, see Tomlinson (1962a), for information on anatomy, see Tomlinson (1969), on cytology, see Mahanty (1970), on ovules, see Mauritzon (1936d); on seed morphology, Humphrey (1896), Mauritzon (1936d), 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?); for labyrinthine nectaries, see Stauffer et al. (2009 and references); on general floral morphology, see Endress (1994b: there may be massive development of endothecial/and/or lignified tissue on the connective side of the anther); and on tapetum, see Furness and Rudall (2001). For the atpA deletion, see Davis et al. (2004), for phenylphenalenones, see Otálvaro et al. (2002), for chromosome numbers, see Song et al. (2004), for phytoliths, see Piperno (2006), and for vessel and tracheid micromorphology, see Carlquist and Schneider (2010).

Phylogeny. Phylogenetic relationships in the order have been much studied, but many are still unclear - see especially Kress (1990b, 1995) and Kress et al. (2001: the tree here [conservative] is based on their 2 gene + morphology successive approximations analysis), 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 Orchidantha, the focus of the paper, was poor. Hence the conservative and rather minimal resolution of relationships in the tree here.

Taxonomy. for a detailed classification of the order, see Kress et al. (2001); pending stabilization of the phylogeny, I have been conservative.

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

Synonymy: Amomales Lindley, Cannales Berchtold & J. Presl, Lowiales Reveal & Doweld, Marantales Martius, Musales Berchtold & J. Presl

MUSACEAE Jussieu, nom. cons.   Back to Zingiberales

Plant cormose; (phenylphenalenones +); SiO₂ bodies decorated 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, cincinni at right angles to the main axis, floral bracts and bracteoles 0; P = T, connate except adaxially, pseudomonocyclic, adaxial inner T free, reduced and ± cucullate, staminate flowers: (A 6), anther wall formation of the basic type [Musella], exothecium +, endothecium poorly developed, staminode 0; tapetum glandular; pistillode +; carpellate flowers: G with intra-ovarian trichomes and mucilage, stigma capitate; ovules (micropyle exostomal), outer integument massive, inner integument ca 3 cells acoss, hypostase +; fruit a berry; seed with chalazal chamber, micropylar collar well developed, aril?, exotesta siliceous, mesotesta massive, 20-25 cells across, sclerotised; n = 9(-11), chromosomes 1.2-2.9 µm long; collar at right angles to cotyledon.

2[list]/41. 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 that are connate except adaxially, where there is a single, free, deeply concave tepal.

Evolution. Divergence & Distribution. 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), while crown group ages suggested by Christelova et al. (2011) are similar, being (80.5-)69.1(-57.8) million years (hpd estimates; Kress and Specht (2006), however, suggest suggested an age of 110 million years, while Paterson et al. (2004) suggested tentatively that Musa might have diverged as much as 142 million years ago... Musaceae - Ensete oregonense - are known fossil in Eocene deposits some 43 million years old from west North America (Manchester & Kress 1993).

Floral Biology. As with Heliconiaceae, the inflorescence may be erect or pendent, and insects, birds, bats and tree shrews are all known pollinators (Nur 1976; Liu et al. 2002; Xue et al. 2005 and references).

Genes & Genomes. There may have been a duplication in the genome (polyploidization) of this clade some 60 million years ago (Lescot et al. 2008).

Economic Importance. For general information on the domestication of the banana (Musa spp. and hybrids), see Heslop-Harrison and Schwarzacher (2007) and for breeding, etc., see Pillay and Tenkouano (2011).

Chemistry, Morphology, etc. 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 Fahn (1983: inflorescence), Tomlinson (1959: anatomy), Kirchoff (1992: ovary), Andersson (1998: general), Graven et al. (1996: seed), Xue et al. (2005: microsporogenesis etc. of Musella), and Xue et al. (2007: embryology of Musella); see Piperno (2006) for phytoliths and domestication.

Phylogeny. Liu et al. (2010) and Li et al. (2010) discuss the phylogeny of the family, in which there are two main clades; the suckering Musella is derived from the non-suckering Ensete in the former, but in some analyses in the latter the two were sister taxa.

HELICONIACEAE Vines   Back to Zingiberales

Rhizome with endodermoid layer; SiO₂ bodies decorated and trough-shaped; stomata polycytic, neighbouring cells with oblique divisions; petiole long; flowers obliquely monosymmetric; P = T, 5 T connate, adaxial-lateral T ± free; A 5, basally adnate to T, stamen opposite free T staminodial, ± hooded; tapetum amoeboid, non-syncytical; pollen functionally monoaperturate; ovule 1/carpel, basal, apotropous, micropyle bistomal; fruit a fleshy schizocarp or drupe; aril 0; endocarp well developed, operculum derived from funicle; testa and tegmen thin, undifferentiated; n = (11) 12, chromosomes 1.4-4.5 µm long; 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 two-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.

Evolution. Divergence & Distribution. 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 occurred 43-21 million years before present (Kress & Specht 2006) or ca 32 million years before present (McKenna & Farrell 2006).

Plant-Animal Interactions. The herbivorous Cephaloleia beetles (Cassidinae+Hispinae, Chrysomelidae) seem to have diversified in the Oligocene coincident with crown Heliconia diversification (McKenna & Farrel 2006).

Floral Biology & Seed Dispersal. Variation in floral and especially inflorescence morphology is considerable (Berry and Kress 1991). Bird pollination is prevalent, and Heliconia is a major nectar resource for sickle-bill humming birds (Eutoxeres) and other hermits at lower altitudes in the New World (they may also nest underneath the leaves); at higher altitudes, as in the Andes, Centropogon (Campanulaceae-Lobelioideae) is a nectar resource for these birds (Stiles 1975, 1981; 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). As in Musaceae, the inflorescences may be erect or pendant. Water may collect in the inflorescence bracts of species with erect inflorescences, and the corolla and later the thick and fleshy pedicel elongate; the result is that first the flower is raised above the surface of the water for the pollinatore and later the fruits are similarly raised for the seed disperser.

Chemistry, Morphology, etc. Rudall and Bateman (2004, see also Kirchoff et al. 2009) 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). Although Kirchoff et al. (2009) suggest that the flower of Heliconia is obliquely asymmetrical (the characterization above follows this interpretation), the floral diagram in Eichler (1875) shows an inverted orientation; clarification is in order. The parietal tissue soon disintegrates.

Some information is taken from Tomlinson (1959: anatomy), Kress (1986b: pollen), Kirchoff (1992: ovary), Andersson (1998; general) and Kirchoff et al. (2009: floral development); Simão et al. (2006) provide information about ovule and seed.

[Strelitziaceae + Lowiaceae]: petiole long, with adaxial and abaxial series of air canals; P = petal-like K + C; A individually opposite the P members, adaxial A of inner whorl staminodial; tapetum glandular [inc. Lowiaceae?]; floral column [sterile apex of ovary] +, stigma 3-lobed; outer integument ca 20 cells across; aril hairy; both exo- and endo-testa developed.

Evolution. 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).

Chemistry, Morphology, etc. The exostomal aril is lobed or fimbriate. For details of anatomy, see Tomlinson (1959), 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, (growth monopodial); phenylphenalenones +; SiO₂ bodies ± spherical; roots with scattered wide vessels and strands of phloem in the pith, stems with vessels; petiole with several arcs of air canals; stomata polycytic, (neighbouring cell divisions oblique); T whorls different or not, C basally connate (2 lateral connate), adaxial member smaller (± cucullate); (A 6 - Ravenala), tapetum glandular, cells to 32-ploid; stigma long-turbinate; ovules with bistomal micropyle; capsule woody; micropylar collar 0, operculum rudimentary, tegmen only a cuticle; (perisperm 0); n = (7, 9) 11, chromosomes?; 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 two-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.

Evolution. Divergence & Distribution. 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).

Floral Biology. Pollination in the group has been much studied, although it is unclear what the plesiomorphic condition might be (cf. Kress et al. 1994).

Chemistry, Morphology, etc. 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: general); 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; 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 +); septal nectary 0, stigma monosymmetric, dorsiventrally flattened, secretory tissue [viscidium] on adaxial side at base, lobes ± fimbriate; ovule with outer integument 14-16 cells across, inner integument ca 4 cells across; seed hairy, micropylar collar?, testa vascularized, exotesta and next two layers lignified, endotesta of radially elongated sclereids; perisperm slight; n = 9, chromosomes 4.3-6.6 µm long; seedling?

1[list]/15. S. China to Borneo (map: J. Kress, pers. comm.; Sakai & Inoue 1999). [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.

Evolution. Divergence & Distribution. Suggestions are that Lowiaceae diverged from other Zingiberales ca 78 million years before present (Janssen & Bremer 2004).

Floral Biology. 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. In some taxa the flowers are very odoriferous, and the apparently nectarless Orchidantha inouei is pollinated by dung beetles (scarabeids: Sakai & Inoue 1999).

Chemistry, Morphology, etc. The family is very poorly known. 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). 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).

Phylogeny. Johansen (2005) provides a phylogeny of the family.

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

Evolution. Divergence & Distribution. 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 occurring 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.

Chemistry, Morphology, etc. Costus, Canna and Kaempferia and at least some other genera have more or less lateral floral 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 anther 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 longitudinal view] in petiole; flowers in pairs, asymmetrical; A ½, staminodes free; stigma not notably expanded; endosperm absent or almost so, cells of chalazal intrusion into nucellus degenerate forming chalazal channel; x = 9.

Evolution. Divergence & Distribution. 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).

Floral Biology. Although both Cannaceae and Marantaceae have asymmetrical flowers and secondary pollen presentation, details of both are quite different in the two.

Chemistry, Morphology, etc. For flowers, see Kirchoff (1983: table of equivalencies of different parts of flowers of Cannaceae and Marantaceae) and Kunze (1984), for ovules, etc., see Johri et al. (1992), for the micropylar collar, see Boesewinkel and Bouman (1984).

CANNACEAE Jussieu, nom. cons.   Back to Zingiberales

Chelidonic acid, aromatic resin +; 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; G muricate, style flattened, pollen deposited on abaxial surface, stigma on one edge; outer integument ca 10 cells across; capsule glandular-muricate; seed pachychalazal, funicle hairy, imbibition lid on raphe, micropylar collar/operculum 0, exotesta and epidermis of chalaza form a malpighian layer, mesotesta sclereidal, endotesta 0; embryo long; n = 9, chromosomes 2.1-3.4 µm long; primary root well developed, collar roots +.

1[list]/10. New World (sub)tropics (map: Maas-van de Kamer & Maas 2008). [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 inferior ovary and fruit.

Evolution. Floral Biology & Seed Dispersal. Pollen is deposited on the abaxial surface of the flattened style whence it is picked up by the pollinator. The seeds may retain their ability to germinate for some 600 years (references in Grootjen & Bouman 1988).

Chemistry, Morphology, etc. Floral diagrams in Eichler (1875) suggest that the prophyll is lateral and the plane of symmetry of the flower inverted. The micropyle becomes zig-zag after fertilization of the flower. Grootjen and Bouman (1988) described a pachychalaza in Cannaceae, with mitosis occurring during ovule development in the chalaza and basal part of the nucellus. This is unlike the other zingiberalean families. The aril is often described as being absent (e.g. Grootjen & Bouman 1981), and the funicular aril mentioned above is unlike that of other Zingiberales.

Phylogeny. For phylogenetic relationships in the genus, see Prince (2010); the North American Canna flaccida is sister to the rest of the clade, whose origin is perhaps to be sought in South America.

Information is taken from Tomlinson (1961b: anatomy), Kubitzki (1998d: general), Tanaka (2001: revision), Maas-van de Kamer and Maas (2008: monograph), and Tanaka et al. (2009: cytology).

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

Aerial stem +/0, rhizome fibrous or woody; (mucilage canals - Thalia); SiO₂ bodies also hat-like; (stomata anomocytic); leaf sheath closed; petiole distinct, often long, pulvinate at the apex [oblique cells]; (inflorescence branched; bracts deciduous); flowers of moderate size, in mirror image pairs [2-flowered cymules], odd K adaxial; C and inner whorl A develop before K and outer whorl A; C, A and style all basally fused, (outer staminodes 0), one inner staminode hooded, another ± fleshy and with callosities, fertile half stamen often with a petaloid lateral appendage; only 1 G fertile, style under tension, becoming curved, pollen deposited on adaxial surface [on "stamp", with secretory area]; ovule 1/carpel, basal, becoming amphitropous, (micropyle bistomal - Phrynium), outer integument 6-8(-12) cells across; (nucellar cap ca 2 cells across), lateral epidermal cells dividing periclinally; (fruit indehiscent); mesotesta tanniniferous, operculum endotestal, (tegmen with thin elongated sclereids); embryo curved, long; n = (-13), chromosomes "very small"; (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.

Evolution. Divergence & Distribution. 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 considerably more speciose than Cannaceae, perhaps because of their distinctive explosive pollen transfer mechanism (Ley & Claßen-Bockhoff 2009).

Marantaceae may have originated in Africa, with subsequent dispersal to South East Asia and the New World (Ley & Claßen-Bockhoff 2011b). Ley and Claßen-Bockhoff (2011b) suggest that the distinctive pollination mechanism of Marantaceae cannot be considered a key innovation, rather, a variety of factors have shaped diversification. Note that there is considerable asymmetry of clade size within the family; the oligospecific Thalia and Haumania may both be sister to far more speciose clades.

Divergence & Distribution. Marantaceae are noted for their complex, enantiostylous, asymmetrical flowers that have an explosive pollination device. The style is held under tension by a hooded inner staminode (the staminodium cucullatum) that has various lobes and appendages (Pischtschan et al. 2010), 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 tripped by the pollinator when it comes into contact with an appendage on the hooded 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 (Ley & Claßen-Bockhoff 2011b).

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. Interestingly, there are no intrinsic barriers to selfing (see Claßen-Bockhoff 1991b for floral morphology and function and Kennedy 2000 for general information, also Andersson 1998; Classen-Bockhoff & Heller 2008 for a developmental study on the diversity of form of some New World Marantaceae). In Africa Marantaceae may be pollinated by large and small bees and sunbirds, and there has been parallel evolution of the various morphologies involved when compared with New World taxa (Ley & Claßen-Bockhoff 2010, 2011a, esp. 2009 for details); the main floral types have evolved in the context of adaptation to different pollinators, but variation in tube length may allow effective pollinations by very different kinds of pollinator within the one floral type (Ley & Claßen-Bockhoff 2010, 2011b). It may be noted that hooded staminodes with a rather simplified morphology may be derived (Pischtschan et al. 2010; Ley & Claßen-Bockhoff 2011b).

During pollination, the sensitive style may move across the flower in 0.33 seconds, most of the movement occurring within about 0.0033 seconds (Claßen-Bockhoff 1991b). The anatomy of the style is distinctive, with a combination of collenchymatous cells, large intercellular spaces, extensive elliptical openings on the walls, and separation of the cells by breakdown of the primary wall starting before the flower opens. As the style moves, there is extensive redistribution of water between the cells (Pischtschan & Claßen-Bockhoff 2010).

Chemistry, Morphology, etc. The plant body is made up of repeating units consisting of a prophyll, a reduced leaf (both with short internodes), and then expanded leaves. These latter vary 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. The inflorescence is almost mind-bogglingly complex (Tomlinson 1961a; Kunze 1985).

The basic orientation of the flower is inverted, the adaxial sepal being median (Pischtschan & Claßen-Bockhoff 2008; Ley & Claßen-Bockhoff 2011b).

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), and for seed morphology, see Grootjen (1983).

Phylogeny. The current classification hardly reflects what is known about phylogeny, 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 themselves other than the Stachyphrynium and Maranta groups (also well supported as sister taxa) is little better (Prince & Kress 2006b: eight genes, all three compartments!). Studies on Asian members of the family, members of the Stachyphryniumand Donax clades, has led to generic realignments there - Phrynium was paraphyletic (Suksathan et al. 2009).

Classification. Andersson and Chase (2001) provide a phylogenetic classification of the family.

Costaceae + Zingiberaceae: leaf ligulate; bracetole lateral; K connate; A 1, staminodes forming labellum, with narrow tube and distinct open limb; exine + [so pollen resistant to acetolysis]; nectary at base of tube, vascularized; style slender, hollow, running between two half anthers, stigma cup- or funnel-shaped; ovule with hypostase; endotesta well developed; chalazal mass in seed ± developed, endosperm helobial, persistent, not that copious; seedling with well developed hypocotyl.

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

Chemistry, Morphology, etc. For possible additional floral synapomorphies, see Specht et al. (2001), for floral development, see Kirchoff (1988a). The massive stamens of Costus, at least, have several vascular bundles in the region of the anthers. Note that van Heel (1988) described the gynoecium of Costus as having septal nectaries, those of Zingiberaceae as lacking them.

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 ³1 layered; (hairs multicellular); leaves spiromonostichous, sheath closed; inflorescence spicate-capitate, unbranched, (flowers/inflorescence axillary); bracts often with abaxial nectaries; abaxial member of outer A whorl staminodial, staminodes 5, connate, forming labellum; pollen aperturate; (G [2]), stigma also bilamellate, fimbriate; outer integument 5-6 cells across; endosperm without starch; n = 9 (14); cotyledon blade-like, photosynthetic, with apical backwardly-directed process; n = 9, chromosomes 2.3-3.7 µm long.

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.

Evolution. Divergence & Distribution. 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.

Floral Biology & Seed Dispersal. Specht (2005) focused on floral evolution and pollination in Costaceae (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 that are visited by ants.

Species with seeds that are dispersed by ants are common in the clade (Lengyel et al. 2010).

Chemistry, Morphology, etc. The bracteole is describes as being lateraland consistently anodic by Kirchoff (1988b) and is drawn in an adaxial-oblique position by Ronse de Craene (2010). 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 Panchaksharappa (1963: embryology), Larsen (1998: general), Grootjen and Bouman (1981: ovule and seed development) and Kirchoff (1988b: floral morphology).

Phylogeny. Specht (2006) provides a detailed phylogeny of the family (see also Specht et al. 2001).

Classification. A generic revision (Specht & Kress 2006) is based on an earlier phylogeny of the family (Specht 2006); a number of morphological features can be used to characterize the genera that they recognize.

ZINGIBERACEAE Martinov, 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); labellum from two lateral staminodes of inner whorl, 2 staminodes of inner whorl petaloid, ?free from labellum, median A of outer whorl 0; nectaries 2, on top of ovary; ovules (1-)many/carpel, outer integument (5-)7-13 cells across; (nucellar cap +), lateral epidermal cells dividing periclinally, epistase +; (embryo sac with postament); capsule fleshy; exotesta of fibriform cells; chalazosperm 0; n = 8-14+; seedling 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.

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); n = (11) 12, chromosomes 0.7-4.5 µm long.

21/ Alpinia (200), Amomum (150), Renealmia (75), Etlingera (70), Riedelia (60), Aframomum (50), Hornstedia (50). Indo-Malesia, tropical Australia; Renealmia, American and African tropics.

Synonymy: Alpiniaceae Link, 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, free filament bow-string like [Globbeae]), (tapetum amoeboid; pollen sulcate - Zingiber); (placentation basal; parietal - Globbeae), style with 2 vascular bundles; (seed carunculate - Globba, Zingiber); (multilayered exotestal epidermis - Globbeae), endotesta parenchymatous; starch grains of perisperm compound (simple - Globbeae), embryo long [Hedychium]; n = (8-)10-12(-14), etc., chromosomes 2.1-5.8 µm long.

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

Synonymy: Curcumaceae Dumortier

• Zingiberaceae are usually large and often aromatic rhizomatous herbs with two-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.

Evolution. Divergence & Distribution. 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).

Renealmia is the only genus of Zingiberaceae in South America, and there seems to have been migration from Africa to America within the last 16 million years (Särkinen et al. 2007). Aframomum is its sister taxon, and there diversification may have begun ca 34.3-25.2 million years ago, although some other estimates are much younger (Auvray et al. 2010).

Floral Biology. Flexistyly (the style changing its orientation during anthesis) is scattered through Alpinioideae (Kress et al. 2005, and references).

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

Chemistry, Morphology, etc. Although Larsen et al. (1998) suggest that Hedychieae lack an operculum in the seed, Grootjen and Bouman (1981) report one from Hedychium itself. Globba and Hedychium and relatives (Zingiberoideae) lack U-shaped cells in the endotesta. Ellettaria has an embryo almost as long as the seed.

Some information is taken from Harling (1949: embryology), Tomlinson (1956: anatomy), Beltran and Kiew (1984: cytology), Larsen et al. (1998: general), and Wood et al. (2000: Hedychium and relatives). For floral development, see Kirchoff (1997: Hedychium, i.a. distinctive floral orientation) and Box and Rudall (2006), and for additional information about Tamija, see Sakai and Nagamasu (2000).

Phylogeny. Relationships in the family are [Siphonochiloideae [Tamijioideae [Alpinioideae + Zingiberoideae]]] - all clades with strong support (Kress et al. 2002: two genes). For a phylogeny of part of Alpinioideae, see Pedersen (2004) and especially Kress et al. (2005); Alpinia is strongly para/polyphyletic, Amomum in polyphyletic. Särkinen et al. (2007) provide a phylogeny of the African-American Renealmia. Pommereschea has a parenchymatous endotesta (Liao & Wu 2000) and also a long style - it is somewhat odd in Alpinieae. Ngamriabsakul et al. (2004) discuss relationships within Zingiberoideae-Zingibereae, and for a phylogeny of Globbeae, see Williams (2003).

Classification. Generic limits in Alpinioideae need attention (e.g. Xia et al. 2004; Kress et al. 2007).