Vincetoxicum
(from vincere, to conquer, and toxicum, poison; in allusion to supposed antidotal powers). ORD. Asclepiadeae. A genus comprising about seventy species of stove, greenhouse, or hardy, erect or twining, perennial herbs or sub-shrubs, inhabiting temperate and warm regions, but rarer in the tropics. Flowers usually greenish-yellow or purplish, sometimes nearly black, in variable cymes; calyx five-parted; corolla somewhat rotate-campanulate, deeply five-eleft; corona affixed to the staminal tube, sub-entire, toothed, shortly five to ten-lobed or nearly five-parted. Leaves opposite or rarely quaternately whorled or alternate. The better-known species are here described. All (except V. pilosum) are hardy perennials. They were formerly classified under Cynanchum (which see for culture).
V. acutum (acute). fl. white; petals oblong, obtuse. July. l. oblong, ovate-cordate, acute. South Europe, 1596. Twiner.
V. fuscatum (brown-flowered). fl. yellow; corolla bearded; umbels simple. July. l. ovate. Stems twining at top. h. 2ft. to 3ft. South-east Europe, 1817. SYN. Cynanchum minus.
V. japonicum (Japanese). fl. whitish, on slender pedicels; corolla segments glabrous; cymes shorter than the leaves, loose-flowered. Summer. l. rounded, shortly acuminate or retuse, very shortly mucronate, paler beneath, the veins softly puberulous and somewhat velvety. Japan. Plant somewhat twining above. (L. & P. F. G. iii., p. 150.) V. medium (intermediate). fl. white; corolla beardless; pedicels hardly longer than the peduncle; umbels often divided. May. l. broadly ovate, obtuse, or ovate-lanceolate, acute. Stems twining at tops. h. 2ft. to 3ft. Eastern Europe, &c.
V. nigrum (black). fl. brown; corolla bearded; pedicels hardly longer than the peduncles; umbels simple. July. l. ovate-lanceolate, acuminate, finely ciliated on the edges, narrower than those of the next species. Stems twining at top. h. 2ft. to 3ft. South Europe, 1596. SYN. Cynanchum nigrum (B. M. 2390).
V. officinale (officinal). Tame Poison. fl. white; corolla beardless; pedicels three times longer than the peduncle; umbels simple. May. l. ovate, acuminate, finely ciliated on the edges when young. Stems erect, furnished with a downy line on each side. h. 1ft. to 3ft. Europe, 1596. SYN. Cynanchum Vincetoxicum. V. pilosum (pilose). fl. white, on short, erect pedicels; peduncles nearly equalling the leaves, many-flowered. July. l. ovate, rounded and mucronulate at apex, rounded or sub-cordate at base. Cape of Good Hope, 1726. Greenhouse, twining sub-shrub. SYN. Cynanchum pilosum (B. R. 111). V. purpurascens (purplish). fl. dull purple, on slender pedicels; cymes long-stalked, many-flowered, proceeding from the axils of the upper leaves. l. narrow-oblong, mucronate, becoming smaller near the ends of the shoots where the flowers appear. Stems and all the green parts slightly downy; when in flower, becoming weaker, with a tendency to twine. Japan, 1850. Half-hardy or hardy perennial.