Asiat. Res. 11: 350 (1810), nom. cons.; R.M. Sm., Edinb. J. Bot. 47: 1-75 (1990)
Herbs, often large, from well-developed rhizome. Leaves many or rarely few on the shoot. Inflorescence usually terminal on the leafy shoot, lax or congested, sometimes surrounded by sterile bracts, sometimes branched; bracts when present open to the base, cincinni 1-many-flowered; bracteole tubular or open to the base, sometimes completely enclosing a cincinnus, sometimes caducous, or absent; flowers varying from small to large, red, yellowish or white to greenish; calyx tubular, 3-dentate, often split down one side; corolla tube usually equal in length to the calyx; lateral staminodes small or absent; labellum erect or concave, sometimes spreading or pendulous, varying in shape, variously lobed or entire; filament absent or present, sometimes appendaged, anther crest present or absent; ovary 3-locular, rarely 1-locular. Fruit indehiscent, globose or ellipsoid; seeds arillate. 2n = 36, 48, 50. (From Kubitzki, et al., p. 489)
Found throughout tropical Asia to New Guinea, Australia, the Solomon Islands, New Hebrides, New Caledonia, Fiji and Samoa.
Phylogeny and Classification:
Recent analysis shows Alpinia to be a paraphyletic group consisting of possibly 6 different genera.
Comprises more than 200 species.
Ecology and Pollination Biology:
Qing-Jun Li et. al. (Nature 2001) described a mechanism found in gingers (Alpinia) called 'flexistyly' that promotes outcrossing and thus genetic diversity. The flower is capable of moving its pollen receiving style out of the way while its anthers release pollen. The cataflexistyled flowers, once fully open, have the stigma above the open anthers from which pollen is released thus preventing self-pollination. By midday the stigma starts to move downward. The anaflexistyled flowers open with the stigma curved downwards away from the closed anthers. By midday the stigma elongates and moves upwards. This mechanism promotes outcrossing and decreased inbreeding. Two phenotypes were found--cataflexistyled and anaflexistyled. View cataflexistyly. View anaflexistyly.
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