Bot. Gaz.57: 123, plates 7–11. 1914
Phenology: Flowering summer–early fall.
Elevation: 200 m
Of conservation concern.
Thismia americana was observed and collected between 1912–1916 from a single site, in a prairie near Chicago, Illinois. It is now possibly extinct. Numerous attempts to relocate the species have been unsuccessful (L. A. Masters 1995); because only a small part of the minute plant is above the level of soil and moss, it could be easily overlooked. This species is believed to be most closely related to T. rodwayi F. von Müller of Australia and New Zealand, presenting a puzzling pattern of distribution (P. J. M. Maas et al. 1986).
Some authors (e.g., R. M. T. Dahlgren et al. 1985; Angiosperm Phylogeny Group 1998) have proposed Thismiaceae to include Thismia and allied African and South American genera.