ASCLEPIADACE.E. (mILKWKKD FAMILY.) 339 



commonly valvate corolla, and in the singular connection of the anthers with 

 the stigma, the cohesion of the pollen into wax-like or (jrannlar masses (pol- 

 linia), etc., as explained under the typical genus Aselepias. 



T'ek/ploca Grjkca, L., a woody climbinp; plant of the Old World, in orua- 

 niental cultivation, and in one or two ])lacos inclined to he spontaneous, repre- 

 sents a trihe with <rrannl(xse pollen loosely ap;gregated in two masses in each 

 anther-cell. It has a hrowuish rotate corolla, very hairy within, and with 5 

 awjied scales in the throat. 



Tribe I. CINANCHEiE. Anthers tippci! with an inflexed or sometimes erect scarious 

 iiicnibrane, tlie fclls lower thai) the top of ilie stigma ; [)olliiiia suspended. 

 * Stems erect or merely decunibint. 

 1 Asclepiodora. Corolla rotate, merely spreading. Crown of 5 hooded fleshy bodies, 

 with a salient crest in each. Leaves alternate. 



2. Aselepias. Corolla reflexed, deeply 5-parted. Crown as in n. 1, but with an incurved 



horn rising from the cavity of each hood. Leaves usually o))posite. 



3. Acerates. Corolla reflexed or merely sjireading. Crown as in n. 1, but with neither 



crest nor horn inside. Leaves mainly alternate. 



# * Stems twining. Leaves mostly opposite. 



4. ICnslenia. Corolla erect. Crown of 5 membranaceous flat bodies, terminated by a 2- 



deft tail or awn. 



5. Vincetoxicuni. Corolla rotate, spreading. Crown a fleshy 5-10-Iobed ring or disk. 

 Tribe II. GONOLOBEiE. Anthere with short if any scarious tip, borne on the mar- 



<tin of or dose under the disk of the stigma ; pollinia horizontal. 



6. Gonolobiis. Corolli rotate. Crown a wavy-lobed fleshy ring. Stems twining. 



1. ASCLEPIODORA, Gray. 



Nearly as in Aselepias, but the corolladobes ascending or spreading, and 

 the hoods destitute of a horn, widely spreading and somewhat incurved, slijv 

 ])er-shaped and laterally compressed, the cavity divided at the ajiex by a crest- 

 like partition. — Umbels .solitary and terminal or corymbed, loosely-flowered. 

 Follicles oblong or ovate, often somewhat muricate with .soft spinous projec- 

 tions. ('A(TKAr;7rjo's and hwpov or Swpeci, the gift ofyKscnUtpius.) 



1 A. viridis, Gray. Almost glabrous; stems short (1° high); leaves 

 alternate, short-petioled, ovate-oblong to lanceolate, 1-2' wide; umbels .sev- 

 eral in a cluster, short-pe<luncled ; flowers large (T in diameter), green, with 

 a ]»urplish crown. (Acerates paniculata, Z)eco/sHf.) — Prairies, 111. to Tex. 

 and 8. Car. June. 



2. A SOLE PI AS, L. Milkwekd. Silkweed. 



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

 5-parted , the divisions valvate in the bud, reflexed, deciduous. Croim of .') 

 hooded bodies seated on the tube of stamens, each containing an incurved horn. 

 Stamens .5, inserted on the ba.se 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-ma.ss ; the two contiguous pollen-masses of adjacent 

 anthers, forming pairs which hang by a slender prolongation of their sum- 

 mits from 5 cloven glands that grow on the angles of the stigma (extricated 

 from the cells by insects, and directing copious i>olleu-tubcs into the point 



