9. Iris verna L. (dwarf iris)

Map 350

Rhizomes often with irregularly thickened areas well separated by more slender portions, less commonly compact. Aerial stems nearly absent, 1–4 cm long, much shorter than the leaves, erect to ascending. Leaves more or less basal, 3–15 cm long, 3–12 mm wide, continuing to elongate after flowering, mostly erect. Clusters of flowers 1 per aerial stem, terminal, with 1–2 flowers, the spathelike bracts unequal, 2–4 cm long, more or less membranous, light green to nearly white, sometimes tinged with pink. Sepals 4–8 cm long (including the fused portion), widely spreading or arching downward, narrowly obovate, with an inconspicuous, longitudinal band of minute, papillose hairs, brownish green in the fused portion, the remainder purple to purplish blue with a yellow longitudinal stripe usually outlined with a narrow, irregular, white band. Petals slightly shorter and narrower than the sepals, erect with the tips arching inward, blue to light purple. Capsules 1.5–2.5 cm long, ovoid, 3-angled, with a single rib at each angle. 2n=42. April–May.

Introduced, escaped from cultivation in Crawford County (native to the southeastern U.S. locally north to Pennsylvania and west to Arkansas, widely cultivated elsewhere). Disturbed grassy areas.

The single locality in Missouri known to date is at the Reis Biological Station of St. Louis University, where plants have spread from an earlier planting.