Family Dioscoreaceae
Synonyms: Stenomeridaceae APNI*
Description: Herbs or rarely shrubs, mostly with stems arising from an underground tuber.
Leaves alternate [or opposite], usually simple [or rarely palmately compound]; lamina with 3–7 longitudinal veins and reticulate secondary venation; stipules absent.
Inflorescence of axillary spikes or racemes, sometimes forming terminal panicles. Flowers actinomorphic, 3-merous, [bisexual] or more often unisexual and then plants dioecious. Tepals 6, in 2 whorls. Stamens usually 6; filaments free; anthers 2-locular, introrse or extrorse, dehiscing by longitudinal slits. Ovary inferior, 3-locular; ovules usually 2 per loculus; stigmas 3.
Fruit usually a 3-lobed capsule [rarely a berry or samara]; seeds 1 or 2 per loculus, usually winged.
Distribution and occurrence: World: 6 gen., 750 spp., trop. to warm-temp. regions. Aust.: 1 gen., 5 spp., Qld, N.S.W., N.T., W.A.
External links:
Angiosperm Phylogeny Website (Family: Dioscoreaceae, Order: Dioscoreales)
Wikipedia Circumscription of families in Dioscorales has been challenging. Broader family circumscriptions were adopted in APG II (2003), based on molecular phylogenetic evidence, with Taccaceae and Trichopodaceae (not in N.S.W.) included in Dioscoreaceae and Thismiaceae included in Burmanniaceae. More recent molecular phylogenetic evidence is conflicting, and we here recognise a narrower concept of Dioscoreaceae, and Thismiaceae and Burmanniaceae as distinct families, in contrast with APG II–APGIV. K.L.Gibbons, 30 June 2023.
Text by G. J. Harden
Taxon concept: National Herbarium of N.S.W., in contrast to APG IV.
| One genus in NSW: Dioscorea |
|
