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.