Aquatic and Wetland Vascular Plants of the Northern Great Plains
36. Apocynaceae, the Dogbane Family
1. Apocynum L. -- Dogbane1. Apocynum cannabinum L. -- Prairie dogbane, Indian hemp
Erect, milky-juiced herb 3-10 dm tall, perennial from spreading rhizomes, weedy and often forming large patches, glabrous or nearly so; stem simple below, dichotomously branched mainly in the upper half. Leaves simple, opposite, sessile and clasping the stem to short-petiolate and not clasping, the lower leaves tending more to be sessile or shorter-petioled than the upper ones; blades ovate to oblong or lanceolate, 3-14 cm long, 0.7-4.5(7) cm wide, acute to rounded and apiculate at the tip, acute to rounded or cordate at the base. Inflorescence of 1 or more dense, terminal cymes; bracts linear to lanceolate, mostly inconspicuous, the lower ones sometimes rather leaflike and conspicuous. Flowers small, white or greenish-white, erect to drooping, perfect, regular; calyx 5-parted to near the base, the lobes linear to lanceolate, 1.2-3(3.5) mm long; corolla 5-lobed, narrowly campanulate to urceolate or short-cylindric, 2.6-4.7 mm long, the lobes triangular, 1/2 or less the length of the corolla tube; stamens 5, inserted near the base of the corolla tube, anthers triangular, slightly adherent to the stigma and converging to form a cone above it; carpels 2, separate below, each with its own ovary, united above and sharing a sessile stigma, ovaries superior, subtended by 5 nectaries that alternate with the stamens. Fruit of 2 or (by abortion) 1, many-seeded follicles, these divergent to pendulous, linear-cylindric, 7-20 cm long; seeds narrowly fusiform, 3-6 mm long, with a coma of white to tawny, silky hairs at the tip. Flowering Jun--Aug, fruiting Aug--Oct. Borders of marshes, lakes and streams and other wet to moist places, often where disturbed; common; (N.S. and N.B. to B.C., s to FL, TX, CA and into n Mex.). A. sibiricum Jacq.
Apocynum cannabinum with enlarged flower and fruit. |
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Return to Family -- Apocynaceae - The Dogbane Family
