ASCLEPIADACE.E. (MILKWEED FAMILY.) 331) 



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

 the stigma, the cohesion of the pollen into icax-like or granular masses (pol- 

 linia), etc., as explained tinder the typical genus Asclepias. 



GR/ECA, L., a woody climbing plant of the Old World, in orna- 

 mental cultivation, and in one or two places inclined to be spontaneous, repre- 

 sents a tribe with grauulose pollen loosely aggregated in two masses in each 

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

 awued scales in the throat. 



Tribe I. CTNANCHE^E. Anthers tipped with an indexed or sometimes erect scarious 

 membrane, the cells lower than the top of the stigma ; jjollinia suspended. 



* Steins erect or merely decumbent. 



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



with a salient crest in each. Leaves alternate. 

 '2. Asclepias. Corolla reflexed, deeply 5-partecl. Crown as in n. 1, but with an incurved 



horn rising from the cavity of each hood. Leaves usually opposite. 



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



crest nor horn inside. Leaves mainly alternate. 



* * Stems twining. Leaves mostly opposite. 



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



cleft tail or awn. 



5. Viiicetoxicmn. Corolla rotate, spreading. Crown a fleshy 5- 10-lobed ring or disk. 



Tribe II. GONOLOBE/E. An there with short if any scarious tip, borne on the mar- 

 gin of or close under the disk of the stigma ; pollinia horizontal. 



6. Gonolobus. Corolli rotate. Crown a wavy-lobed fleshy liug. Stems twining. 



1. ASCLEPIODORA, Gray. 



Nearly as in Asclepias , but the corolla-lobes ascending or spreading, and 

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

 per-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 murk-ate with soft spinous projec- 

 tions. ('AffKAyirtos and Siapov or Swped, the gift of jEsculapius.) 



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-pednncled ; flowers large (!' in diameter), green, with 

 a purplish crown. (Acerates paniculata, Decaisne.) Prairies, 111. to Tex. 

 and S. Car. June. 



2. ASCLEPIAS, 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 sum- 

 mits 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 



