Lespedeza hirta (L.) Hornem.
Hairy Bush Clover
Family - Fabaceae/Faboideae
Habit - Perennial forb.
Stem - Ascending to erect, sometimes arched, to 1.5 m long, 1.5-5.0 mm in diameter near the base, generally unbranched below the midpoint, densely pubescent with mostly spreading hairs, often with a silvery or tawny appearance, the hairs not in bands, sometimes becoming sparsely pubescent toward the base.
Leaves - Alternate, petiolate, trifoliate, stipulate. Primary median leaves with the petiole mostly relatively long and slender, 5-20 mm long, 0.2-0.5 mm wide, densely spreading-hairy. Stipules 3-8 mm long, narrowly triangular toward the stem base, grading to hairlike toward the tip. Leaflets 15-40 mm long, 10-30 mm wide, 1.3-1.8 times as long as wide, elliptic to broadly oblong or oval, those of the uppermost leaves sometimes nearly circular, rounded at the base, rounded or sometimes minutely notched at the tip, sometimes appearing grayish-tinged, but lacking a silvery or tawny sheen, the upper surface sparsely to moderately pubescent with mostly appressed hairs, the undersurface moderately to densely pubescent with appressed and usually also more or less spreading hairs. Axillary leaves usually absent.
Inflorescences - Axillary or appearing terminal, clusters or racemes, relatively dense and ascending, longer than the subtending leaves. Flowers mostly 10-20 per cluster, the axis usually visible for most of the length, often hidden by the flowers near the tip.
Flowers - Calyces 5-lobed, the tube 1.0-1.5 mm long, the lobes 4-9 mm long, minutely hairy. Corollas papilionaceous, 6-8 mm long, cream-colored or pale yellow with purple markings on the banner, the keel shorter than the wings, glabrous. Stamens 10, 9 of the filaments fused and 1 free nearly to the base, the anthers small, attached near the midpoint, all similar in size. Ovary ellipsoid to ovoid, sessile or short-stalked, the style slender, usually glabrous, straight in chasmogamous flowers and recurved in cleistogamous flowers, persistent at fruiting, the stigma small and terminal.
Fruits - Fruits from open flowers 5-8 mm long, the calyx about as long as or slightly longer than the fruit; fruits from cleistogamous flowers 4-7 mm long, the calyx about as long as or slightly longer than the fruit. Seeds 2.5-3.0 mm long, brown or purplish black.
Flowering - July - October.
Habitat - Prairies, glades, forest openings, savannas, bluffs, old fields.
Origin - Native to the U.S.
Lookalikes - Broadly, L. capitata.
Other info. - This species is common in the southern half of Missouri, but known so far from only one county north of the Missouri River. Its North American distribution falls within the eastern half of the continental U.S., and also includes parts of Canada.
The plant is reasonably easy to identify due to its tall stature, hirsute stems, and rounded leaves. It is a common bush clover species of the dry, cherty slopes of the Ozarks, and a host species to numerous butterflies.
Photographs taken at Holly Ridge Conservation Area, Stoddard County, MO, 9-12-2010, and near Royal Gorge, Iron County, MO, 8-26-2016 (SRTurner).