1. Cleistes bifaria (Fernald) Catling & Gregg, Lindleyana. 7: 65. 1992.
Smaller spreading pogonia
Cleistes divaricata (Linnaeus) Ames var. bifaria Fernald, Rhodora 48: 186, plate 1048. 1946
Plants (12–)15–46(–64) cm (in flower). Leaves: blades on flowering stems, (2.5–)45–145 × (4–)6–25 mm. Flowers: sepals 24–55 × (2–)3–5 mm; petals 21–36 × 6–10(–12) mm; lip 21–33(–38) × 13–16 mm, central keel relatively thick, 2.4–2.6 mm wide, very slightly grooved, groove 0.3 mm deep and verrucose or braided with 5–7 discontinuous ridges; column 13–19 mm. Capsules (9–)27–41(–81) × (3.2–)4–8(–8.5) mm. 2n = 18.
Flowering Apr--May (coastal plain) --Jul (mountains). Savannas, meadows, openings in oak or pine woodlands, mountain habitat often xeric, in acidic soil; 0--1000 m; Ala., Fla., Ga., Ky., La., Miss., N.C., S.C., Tenn., Va., W.Va.
A station in Barbour County, West Virginia, is 240 km north of other stations and may be a result of introduction (K. B. Gregg 1989).
Cleistes bifaria has been treated as a variety of the following species; it is readily separated by its relatively short column, which is correlated with the relatively small size of other floral parts, and differences in lip keel. It is, to a large extent, isolated from the following taxon by geographic distribution and flowering time where their distributions overlap (P. M. Catling and K. B. Gregg 1992).
Gregg, K. B. 1989. Reproductive biology of the orchid Cleistes divaricata (L.) Ames var. bifaria Fernald growing in a West Virginia meadow. Castanea 54: 57–78.