Calyx 5- (or 3–4-) lobed. Corolla wheel-shaped, 5-lobed. Stamens 5, separate; the membranaceous hairy filaments shorter than the anthers. Stigmas 3. Capsule prismatic or elongated-oblong, 3-celled, opening by 3 small lateral valves.—Low annuals, with axillary blue or purplish flowers, in American species dimorphous, the earlier being cleistogamous. (Name from Speculum Veneris, the early name of the common European species.)
1. S. perfoliàta, A. DC. Somewhat hairy (3–20´ high); leaves roundish or ovate, clasping by the heart-shaped base, toothed; flowers sessile, solitary or 2–3 together in the axils, only the upper or later ones having a conspicuous and expanding corolla; capsule oblong, short, straight, opening rather below the middle; seeds lenticular.—Sterile open ground; common. May–Aug.
2. S. leptocárpa, Gray. Minutely hirsute or nearly glabrous (6–12´ high); leaves lanceolate, with flowers closely sessile in their axils; calyx-lobes of lower flowers 3; capsule nearly cylindrical (6–9´´ long, 1´´ thick), inclined to curve, opening by one or two uplifted valves near the summit; seeds oblong.—W. Mo. and Ark. to Col. and W. Tex. Expanded corolla 6–9´´ wide.
2. CAMPÁNULA, Tourn. Bellflower.
Calyx 5-cleft. Corolla generally bell-shaped, 5-lobed. Stamens 5, separate; the filaments broad and membranaceous at the base. Stigmas and cells of the capsule 3 in our species, the short pod opening on the sides by as many valves or holes.—Herbs, with terminal or axillary flowers; in summer. (A diminutive of the Italian campana, a bell, from the shape of the corolla.)
[*] Style straight; openings of capsule below the middle.
[+] Coarse pubescent many-flowered European species, sparingly naturalized; perennial.
C. rapunculoìdes, L. Smoothish, slender, erect; stem-leaves ovate-lanceolate, pointed, the lower long-petioled and heart-shaped; flowers nodding, single in the axil of bracts, forming racemes; corolla oblong, 1´ long.—Roadsides and fields, Canada and N. Eng. to Penn.
C. glomeràta, L. (Clustered B.) Somewhat hairy, stout and erect, 1° high; stem-leaves oblong or lanceolate, cordate-clasping; flowers sessile, clustered in the upper axils, forming a leafy head; corolla open-bell-shaped, 1´ long.—Roadsides, E. Mass.
[+][+] Slender perennials, mostly glabrous; flowers one or few, on slender peduncles.