394 ASCLEPIADACE^. (jIILKWEED FAMILY.) 



ajmes loose, spreading, mostly longer than the leaves ; corolla (pale rose-color, 

 4" broad) open-hell-shaped, with reuolute lobes, the tube much longer than the ocate 

 pointed divisions of the calyx. — Varies, with the leaves downy underneath. — 

 Borders of thickets : common northward. June, July. — Pods 3' - 4' long, 

 pendent. 



2. A. cann^binum, L. (Indian Hemp.) Stem and branches upright 

 or ascending, terminated by erect and close many-flowered cymes, which are usually 

 shorter than the leaves ; corolla (greenish-white) with nearly erect lobes, the tube 

 not longer than the lanceolate divisions of the calyx. — Var. glabekeimum, DC. 

 Entirely smooth ; leaves oblong or oblong-lanceolate, on short but manifest 

 petioles, obtuse or rounded, or the uppermost mostly acute at both ends. — 

 Var. PUBESCENS, DC. Leaves oblong, oval, or ovate, soft-downy underneath 

 or sometimes on both sides, as well as the cymes. (A. pubescens, R. Br.) — 

 Var. HTPERicir6LiuM. Leaves more or less heart-shaped at the base and on 

 very short petioles, commonly smooth throughout. (A. hypericifoliuni, Ait.) 

 — River-banks, &c. : common. July, Aug. — Plant 2° - 3° high, much more 

 upright than the last ; the flowers scarcely half the size. 



Okder 80. ASCliEPIADACBiE. (Milkweed Family.) 



Plants with milky juice, and opposite or tohorled (rarely scattered') entire 

 leaves ; t the follicular pods, seeds, anthers (connected with the stigma), sensible 

 properties, Sfc.,just as in the last family ; from which they differ in the com- 

 monly valvale corolla, and in the singular connection of the anthers with the 

 stigma, the cohesion of the pollen into wax-like or granular masses, &c., as 

 explained under the first and tj'pical genus. 



Tribe I. ASCLEPIADK.^. PilameDts monadelphoua. Pollen-masses 10, waxy, 

 fixed to the stigma in pairs by a gland, hanging vertically. 



1. A§clepia8. Calyx and corolla reflexed, deeply 5-parted. Crown of 5 hooded fleshy bod- 



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



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



without a horn inside. 

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

 by a 2-cleft tail or awn. 



4. Vincetoxicum. Calyx and wheel-shaped corolla spreading. Crown a fleshy 6-10- 



lobed ring or disk. 



Tribe II. GONOLOBB.^. Filaments monadelphoua. Pollen-masses 10, affixed to the 

 stigma in pairs, horizontal. 



5. Gonolobus. Corolla wheel-shaped. Crown a wavy-lobed fleshy ring. 



Tribe III. PERIPIjOCE.*!. Filaments distinct or nearly so. Pollen-masses granu- 

 lar, separately applied to the stigma. 



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



1. ASCL^FIAS, L. Milkweed. Silkweed. 



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

 5-parted ; the divisions valvate in the bud, reflexed, deciduous. Crown of 5 

 hooded bodies (nectaries, L.) seated on the tube of stamens, each containing 



