Thismia Griff.
Fls us. solitary, terminal on short lateral branch, large for size of plant. Per.-tube campanulate to urceolate, circumscissile just above ovary; lobes 6, the inner 3 us. larger and sts connivent or ± connate at their tips to form an erect mitre with 3 openings or fenestrae. Stamens 6; filaments short, attached to annulus at mouth of per.-tube and deflexed inwards; anthers free or connate into a tube, dehiscing by longitudinal slits. Ovary 1-locular, with 3 placentae us. suspended by slender stalks between roof and floor of the cavity; style short and thick; stigmas 3, simple or bilobed. Fr. turbinate, us. fleshy, crowned by thick ring of per.-tube base and by persistent style and stigmas. Saprophytic fleshy herbs perennating by tuberous, coralloid or vermiform subterranean parts. Stems us. short and unbranched. Lvs small, scalelike, those immediately below fl. often forming an involucre. Some 2 dozen spp. of Australia, Indomalaysia, India and America.
The extraordinary placentation seen in this and in related genera is figured by Hutchinson (Fam. Flow. Plants 2, 1959, 688, fig. 412), by Jonker (loc. cit. 258, fig. 20) and by Larsen (Dansk bot. Ark. 23, 1965, 172). Cheeseman's figure Ill. N.Z. Fl. 2, Pl. 191, fig. 12) shows parietal placentae which, according to Campbell (T.R.S.N.Z. Bot. 3, 1968, 211), later become free from the lateral walls.
