4. Iris germanica L. (German iris, blue flag)

Pl. 91 d; Map 345

Rhizomes lacking conspicuously thickened areas, often somewhat flattened. Aerial stems 40–100 cm long, longer than the leaves, erect. Leaves basal and reduced on the aerial stems, 30–70 cm long, 25–45 mm wide, erect to stiffly ascending. Clusters of flowers mostly terminal on the main stem and erect branches, each with 3–5 flowers, the spathelike bracts unequal, 3–6 cm long, herbaceous and green, often with broad, white to light brown or purplish-tinged, papery margins. Sepals 8–12 cm long, arching downward, broadly obovate, with a conspicuous beard of long, coarse hairs extending in a line from the narrow base onto the lower half of the broader, apical portion, usually violet-blue (see discussion below), variously marked with a darker area and a white, yellow, or brown beard and veins. Petals subequal to the sepals or slightly shorter, erect with incurved tips, violet-blue, usually somewhat lighter than the sepals. Capsules (rarely produced) 4–7 cm long, oblong-elliptic in outline, 3-angled, with a single rib at each angle. 2n=36, 44, 48. April–June.

Introduced, escaped from cultivation at scattered sites (of uncertain origin, but probably native to southern Europe, now cultivated nearly worldwide, and naturalized sporadically in the U.S.). Roadsides, railroads, and old homesites.

Iris germanica is the most widely cultivated species in the genus, and numerous horticultural variants are known, any of which might escape in Missouri. These include plants of various heights and various flower colors, ranging from the more commonly seen violet-blue to light purple, reddish purple, white, or yellow, all with various color markings, particularly along the beard.