6. Gonolobus. Corolla rotate. Crown a wavy-lobed fleshy ring. Stems twining.
1. ASCLEPIODÒRA, Gray.
Nearly as in Asclepias, but the corolla-lobes ascending or spreading, and the hoods destitute of a horn, widely spreading and somewhat incurved, slipper-shaped and laterally compressed, the cavity divided at the apex by a crest-like partition.—Umbels solitary and terminal or corymbed, loosely-flowered. Follicles oblong or ovate, often somewhat muricate with soft spinous projections. (Ἀσκληπιός and δῶρον or δωρεά, the gift of Æsculapius.)
1. A. víridis, Gray. Almost glabrous; stems short (1° high); leaves alternate, short-petioled, ovate-oblong to lanceolate, 1–2´ wide; umbels several in a cluster, short-peduncled; flowers large (1´ in diameter), green, with a purplish crown. (Acerates paniculata, Decaisne.)—Prairies, Ill. to Tex. and S. Car. June.
2. ASCLÈPIAS, L. Milkweed. Silkweed.
Calyx 5-parted, persistent; the divisions small, reflexed. Corolla deeply 5-parted, the divisions valvate in the bud, reflexed, deciduous. Crown of 5 hooded bodies seated on the tube of stamens, each containing an incurved horn. Stamens 5, inserted on the base of the corolla; filaments united in a tube which encloses the pistil, anthers adherent to the stigma, each with 2 vertical cells, tipped with a membranaceous appendage, each cell containing a flattened pear-shaped and waxy pollen-mass; the two contiguous pollen-masses of adjacent anthers, forming pairs which hang by a slender prolongation of their summits from 5 cloven glands that grow on the angles of the stigma (extricated from the cells by insects, and directing copious pollen-tubes into the point where the stigma joins the apex of the style). Ovaries 2, tapering into very short styles; the large depressed 5-angled fleshy stigmatic disk common to the two. Follicles 2, one of them often abortive, soft, ovate or lanceolate. Seeds anatropous, flat, margined, bearing a tuft of long silky hairs (coma) at the hilum, downwardly imbricated all over the large placenta, which separates from the suture at maturity. Embryo large, with broad foliaceous cotyledons in thin albumen.—Perennial upright herbs, with thick and deep roots; peduncles terminal or lateral and between the usually opposite petioles, bearing simple many-flowered umbels, in summer. (The Greek name of Æsculapius, to whom the genus is dedicated.)
§ 1. Corneous anther-wings broadest and usually angulate-truncate and salient at base; horn conspicuous.
[*] Flowers orange-color; leaves mostly scattered; juice not milky.
1. A. tuberòsa, L. (Butterfly-weed. Pleurisy-root.) Roughish-hairy (1–2° high); stems erect or ascending, very leafy, branching at the summit, and bearing usually numerous umbels in a terminal corymb; leaves from linear to oblong-lanceolate, sessile or slightly petioled; divisions of the corolla oblong (greenish-orange); hoods narrowly oblong, bright orange, scarcely longer than the nearly erect and slender awl-shaped horns; pods hoary, erect on deflexed pedicels.—Dry fields, common, especially southward.—Var. decúmbens, Pursh. Stems reclining; leaves broader and more commonly opposite, and umbels from most of the upper axils.—Ohio to Ga., etc.
[*][*] Corolla bright red or purple; follicles naked, fusiform, erect on the deflexed pedicels (except in n. 5); leaves opposite, mostly broad.