Including Amom(ac)eae A. Rich.
Excluding Costaceae
Habit and leaf form. Herbs; bearing essential oils. Perennial; with neither basal nor terminal aggregations of leaves; rhizomatous. Self supporting, or epiphytic. Mesophytic. Leaves evergreen; alternate; distichous; `herbaceous', or leathery; petiolate, or subsessile, or sessile; sheathing (the sheaths often constituting pseudostems, cf. Musa). Leaf sheaths tubular, or not tubular; with free margins. Leaves usually without marked odour (often by contrast with aromatic roots and/or fruits); simple. Lamina entire; linear, or lanceolate, or oblanceolate, or oblong, or ovate; pinnately veined; cross-venulate (?).
General anatomy. Plants with silica bodies. Accumulated starch other than exclusively `pteridophyte type'.
Leaf anatomy. Epidermis containing silica bodies (spherical).
The mesophyll with spherical etherial oil cells; containing calcium oxalate crystals. The mesophyll crystals druses, or solitary-prismatic (no raphides). Minor leaf veins without phloem transfer cells (Zingiber). Vessels absent.
Stem anatomy. Secondary thickening absent. Xylem with vessels (2 Renealmia species only), or without vessels (mostly). Vessel end-walls scalariform. Sieve-tube plastids P-type; type II.
Root anatomy. Root xylem with vessels. Vessel end-walls scalariform (nearly always), or scalariform and simple (occasionally).
Reproductive type, pollination. Hermaphrodite. Floral nectaries present. Nectar secretion from the gynoecium (via one or three glands, variously shaped, at the style base), or from the gynoecium and from the androecium (sometimes also from the staminodes). Entomophilous, or ornithophilous (the family exhibiting a variety of epigynous and staminodial nectariferous glands).
Inflorescence, floral, fruit and seed morphology. Flowers aggregated in `inflorescences'; in cymes, or in spikes. The terminal inflorescence unit cymose, or racemose. Inflorescences terminal; spikes or thyrses. Flowers bracteate; bracteolate, or ebracteolate; medium-sized; very irregular; zygomorphic. The floral asymmetry involving the perianth and involving the androecium. Flowers 3 merous; cyclic; obscurely pentacyclic. Perigone tube absent. Hypogynous disk absent.
Perianth with distinct calyx and corolla; 6; joined; 2 whorled; isomerous; different in the two whorls. Calyx 3; 1 whorled; gamosepalous; entire, or lobulate, or lobed; unequal but not bilabiate, or regular; valvate (or splitting on one side). Corolla 3; 1 whorled; gamopetalous; unequal but not bilabiate (the median petal usually bigger).
Androecium 5. Androecial members free of the perianth; coherent (the lateral members of the inner whorl fused to form a petaloid labellum, the laterals of the outer whorl when present sometimes appearing as lobes on the functional stamen); 2 - whorled. Androecium including staminodes. Staminodes 4, or 2 (the lateral pair of the outer whorl present or absent, the outer median being missing, the fused laterals of the inner whorl forming the conspicuous labellum); petaloid (the members of the outer whorl usually much smaller). Stamens 1 (the median member or the inner whorl); reduced in number relative to the adjacent perianth; op\po\siti\peri\anthial. Anthers dehiscing via longitudinal slits; introrse; tetrasporangiate; appendaged, or unappendaged. Endothecium developing fibrous thickenings. The thickenings spiral. Anther epidermis persistent. Microsporogenesis successive. The initial microspore tetrads isobilateral (usually), or tetrahedral, or T-shaped, or linear. Anther wall initially with more than one middle layer (4 to 6). Tapetum amoeboid, or glandular. Pollen grains aperturate, or nonaperturate (usually); when aperturate, 1 - aperturate; sulcate; 2-celled.
Gynoecium 3. Carpels isomerous with the perianth. Gynoecium syncarpous; eu-syncarpous; superior. Ovary 1 locular, or 3 locular. The `odd' carpel anterior. Gynoecium stylate. Styles 1; apical; much longer than the mature ovary (slender, passing between the thecae of the anther). Stigmas 1; wet type; papillate; Group III type. Placentation when unilocular parietal to basal, or free central (rarely); when trilocular, axile. Ovules in the single cavity when unilocular, 4-100; 4-50 per locule; arillate; anatropous, or orthotropous; bitegmic; crassinucellate. Outer integument not contributing to the micropyle. Embryo-sac development Polygonum-type. Polar nuclei fusing prior to fertilization. Antipodal cells not formed (the nuclei ephemeral). Synergids pear-shaped, or hooked. Hypostase present. Endosperm formation helobial. Embryogeny asterad.
Fruit fleshy, or non-fleshy; dehiscent, or indehiscent; a capsule, or capsular-indehiscent, or a berry. Seeds thinly endospermic. Perisperm present. Seeds with starch. Cotyledons 1. Embryo achlorophyllous (Zingiber sp.); straight.
Physiology, biochemistry. Cyanogenic (?Hedychium), or not cyanogenic. Proanthocyanidins present (usually), or absent (Globba); delphinidin (Brachychilum), or cyanidin and delphinidin. Flavonols present (Globba, Brachychilum), or absent (4 genera); kaempferol (in Globba), or myricetin (sic - in Brachychilum). Ellagic acid absent. Saponins/sapogenins present (Alpinia), or absent. C3. C3 recorded in Curcuma, Elettaria, Zingiber. Anatomy non-C4 type (Curcuma, Elettaria, Zingiber).
Geography, cytology. Tropical. Pantropical, but chiefly Indomalayan. X = (9-)12(-26).
Taxonomy. Subclass Monocotyledonae. Superorder Zingiberiflorae; Zingiberales (cf. Costaceae). Species 700. Genera about 45; Afromum, Amomum, Curcuma, Hedychium, Kaempferia, Zingiber, Globba, etc.
Economic uses, etc. The sources of ginger root, numerous fragrant oils for perfumery, cardamom seed, and horticultural ornamentals.
Illustrations. zingi147.gif zingi761.gif zingi165.gif
