1. Nemastylis geminiflora Nutt. (prairie iris)
Pl.
92 c, d; Map 352
Nemastylis acuta (Barton) Herb.
Leaves of the aerial stems 1–3, the broadest leaf blades 5–11 mm wide.
Spathelike bracts enclosing 1–2 flowers. Sepals 25–30 mm long. Stamens with the
filaments free or fused only at the base, the anthers 0.6–1.2 cm long, becoming
tightly spirally twisted after shedding the pollen. Capsules 10–20 mm long,
obovoid, tapering at the base, abruptly and broadly rounded at the tip or
appearing as though cut straight across. Seeds 2.0–2.5 mm long, broadly
obovoid-angular, tapering to a short, beaklike tip at 1 end, dark brown. 2n=56.
April–May.
Scattered in the Unglaciated Plains Division and in the eastern portion of the
Ozarks and Ozark Border Divisions (Kansas to Texas west to Missouri and
Alabama). Glades and prairies on calcareous substrates.
This attractive species has flowers with a sky blue perianth and open in the
morning and wither by mid- to late afternoon. The flowers frequently are paired
in the spathes.