Flora of North America species comparison

prostrate or erect, glabrous or slightly hairy.

prostrate, 15–30 cm, hairy.

cauline, opposite [whorled];

petiole obscure or absent;

blade fleshy (B. monnieri) or not, not leathery, margins entire, crenate, or serrate.

glabrous;

blade base narrowly cuneate, margins crenate, apex rounded with a narrow petiole-like base.

axillary, flowers solitary or in pairs;

bracts absent.

present or absent;

bracteoles present [absent].

10–12 mm.

bisexual;

sepals 4 or 5, distinct, outer wider than inner, ovate, lanceolate, or oblong, calyx radially or bilaterally symmetric, campanulate;

corolla white (sometimes with yellow throat), pink, or violet-blue, radially or bilaterally (B. repens) symmetric, regular or weakly bilabiate, rotate or campanulate, rarely tubular, tube base not spurred or gibbous, throat not densely pilose internally, lobes 4 or 5, abaxial 2 or 3, adaxial 2;

stamens 2–4, adnate to corolla, didynamous or equal, filaments glabrous;

staminode 0;

ovary 2-locular, placentation axile;

stigmas peltately flattened and semicapitate.

sepals 4(or 5), ovate to oblong, calyx radially symmetric;

corolla white with yellow throat, 3–5 mm;

stamens 3 or 4, didynamous.

capsules, dehiscence septicidal-loculicidal or loculicidal.

80–120, brownish black, ellipsoid to cylindric, reticulate, wings absent.