ASCLEPIADACEiE. (MILKWEED FAMILY.) 351 



Synopsis. 



Tribe I. ASCLEPIADE^E. Filaments monadelphous. Pollen-masses 10, waxy, 

 fixed to the stigma by pair.-', pendulous and vertical. 



1. ASCLEPIAS. Calyx and corolla renewed, deeply 5-parted. Ci own of 5 hooded Eeshy bod- 



ies (nectaries, L ), with an incurved horn rising from the cavity of each. 



2. ACERATES. Calyx and corolla reflexed or merely spreading Crown as in No. 1, but 



without a horn inside. 

 8 ENSLEXIA. Calyx and corolla erect. Crown of 5 membranaceous bodies, flat, terminated 

 by a 2-cleft tail or awn. 



Tribe II GONOLOBEiE. Filaments monadelphous. Pollen-masses 10, affixed to the 

 stigma in pairs, horizontal. 



4. GONOLOBUS. Corolla wheel-shaped Crown a wavy-lobed fleshy ring. 



Tribe III. PERIPLOCEjE. Filaments distinct or nearly so. Pollen-masses granu- 

 lar, separately applied to the stigma. 



5. PERIPLOCA Corolla wheel-shaped, with 5 awned scales in the throat. 



1. ASCLEPIAS, L. Milkweed. Silkweed. 



Calyx 5-paned, persistent ; the divisions small, spreading. Corolla deeply 

 5-parted; tin- divisions valvate in the hud, reflexed, deciduous. Oroum of 5 

 hooded hodies (nectaries, L.) seated on the tube f stamens, em-h containin 

 incurved horn. Stamens 5, inserted on the base of the corolla: filaments united 

 in a tube {gynostegium) which encloses the pistil : anthers adherent to the stigma, 

 each with 2 vertical cells, tipped with a membranaceous appi , 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 pro- 

 longation of their summits from 5 cloven glands that gnw on the angles of the 

 stigma (usually extricated from the cells by the agency of insects, and directing 

 copious pollen-tubes into the point where the stigma joins the apex of the styles). 

 Ovaries 2, tapering into very short styles: the large depressed 5-angled ii 

 stigma common to the two. Follicles 2, one of them often abortive, soft, ovate 

 or lanceolate. Seed-; anatropous, flat, margined, downwardly imbricated all 

 over the large placenta which separates from the suture sit maturity, furnished 

 with a long tuft of silky hairs (coma) at the hilum. Embryo large, with broad 

 foliaceous cotyledons in thin albumen. —Perennial u;., with thick and 



deep roots: peduncles terminal or mostly lateral and between the petiol 

 rag simple many-flowered umbels. Leaves usually transversely veiny. (The 

 Greek name of sEsculajuus, to whom the genus is dedicated.) See Add 

 * Pods clothed with soft spinous projections. 

 1. A. Consists, Decaisne. (Common Milkweed or Silkweed.) 

 Stem large and stout, somewhat branched; leaves ovate-elliptical, with a slight 

 point, spreading, contracted at the base into a short hut distinct petiole, minutt ly velvety- 

 downy underneath as well as the peduncles and branches; divisions of the corolla 

 ovate (greenish-purple), about one fourth the length of the very numerous pedi- 

 cels ; hoods of the crown ovate, obtuse, with a lobe or tooth on each side of the short 

 and stout claic-like horn; pods ovate, covered with weak spines and won!///. (A. Sy- 

 riaca, L., but the plant belongs to this country only.)— Eich soil, fields, &c; 

 common. July. — Plant 3° - 4° high ; leaves 4' - 8' long, pale. 



