PLANTS: Perennial herbs with milky juice. STEMS: several, erect or ascending from a woody rootstock. LEAVES: alternate, hairy or glabrous, ovate to linear, gradually to abruptly narrowing apically. INFLORESCENCE: a terminal, compound cyme. FLOWERS: calyx green, the lobes equal, accuminate; corolla white, blue, or pinkish, salverform, the lobes spreading to reflexed; stamens included in the corolla tube, the anthers not connivent; ovules numerous. FRUIT: terete or constricted between the seeds. SEEDS: several, naked, corky, cylindrical or elliptic. NOTES: 14 spp. in U.S. and n Mex.; 1 sp. in Japan. (for Dr. C. Amson). McLaughlin, S. P. 1982. Ann. Missouri Bot. Gard. 69:336-350. REFERENCES: McLaughlin, Steven, P. 1994. Apocynaceae. J. Ariz. - Nev. Acad. Sci. Volume 27, 164-168.
Cal deeply 5-parted; cor salverform, villous in the throat, its lobes lanceolate; anthers separate; ovaries 2, without nectaries; ovules many; follicles elongate, linear, cylindric or somewhat moniliform; seeds naked; erect perennial herbs with alternate or irregularly scattered lvs and terminal cymes of small but handsome blue fls. 25, N. Amer. and Japan.
Gleason, Henry A. & Cronquist, Arthur J. 1991. Manual of vascular plants of northeastern United States and adjacent Canada. lxxv + 910 pp.