ASCLEPIADACE^. (MILKWEED FAMILY.) 351 



Synopsis. 



Tmbi I. ASCIiHFIADBA!. Filaments monadelphouB. PoUen-mMBes 10, waxy, 

 fixed to the stigma by pairs, pendulous and Tertical. 



1. ASCLBPIAS. Oalyx and corolla reflexed, deeply 5-parted. Crown of 5 hooded fleshy bod- 



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



2. ACERATES. Calyx and corolla reflezed or merely spreading. Crown a£ in No, 1, but 



without a horn inside. 

 8. EN3LEN1A. Calyx and corolla erect. Crown of 5 membranaceous bodies, flat, terminated 

 by a 2-cleft tail or awn. 



Tkibe II. C>ONOIjOBE:.n:. Filaments monadelphous. Pollen-masses 10, affixed tA the 

 stigma in pairs, horizontal. 

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



TioBE III. FE:RIPIiOCE:.31. Filaments distinct or nearly so. Folleu-maaBes granu- 

 lar, separately applied to the stigma. 



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



1> ASCIiEFIAS, L, Milkweed. Silkwbed. 



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

 5-pavted; the divisions valvate in the bud, reflexed, deciduous. Cnvm of 5 

 hooded bodies (nectaries, L.') 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 {gynostegium) 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 pro- 

 longation of their summits from 5 cloven glands that gi'ow 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 fleshy 

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

 or lanceolate. Seeds anatropous, flat, margined, downwardly imbricated all 

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

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

 foliaceous cotyledons in thin albumen. — Perennial upright herbs, with thick and 

 deep roots : peduncles terminal or mostly lateral and between the petioles, bear- 

 ing simple many-flowered nmbels. Leaves usually transversely veiny. (The 

 Greek name of uSSscidapius, to whom the genus is dedicated.) 

 # Pods clothed with soft spinous projections. 



1. A. CoiTBUti, 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 but distinct petiole, minutely velvety- 

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

 ovate (greenish-purple), about one foui'th 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 daic-Uke horn ; pods ovate, covered with weak spines and woolly. (A. Sy- 

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

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



