238 ASCLEPIADACE^E. (MILKWEED FAMILY.) 



and even lanceolate, from skort-petioled to sessile, with a rounded or obscurely cor- 

 date base: cymes erect, densely flowered: corolla greenish-white or slightly 

 flesh-color, smaller than in the former, with almost erect lobes and tube not 

 longer than the lanceolate cabjx-lobes. Same range as last. Exceedingly 

 variable. 



ORDER 49. ASCLEPIADACE^E. (MILKWEED FAMILY.) 



Plants with milky juice, and opposite or whorled (rarely scattered) 

 entire leaves ; general structure of flowers and fruit as in Apocynacece ; 

 but differing in the connection of the anthers with the stigma, the co- 

 hesion of the pollen into wax-like or granular masses, etc. A corona 

 (crown) , of 5 parts or lobes, between the corolla and filaments, is adnate 

 either to the one or the other. The tube of monadelphons filaments 

 is called the column. Ours all belong to the Cynanchece, which have 

 anthers tipped with an inflexed or sometimes erect scarious membrane ; 

 the polliniferous cells lower than the top of the stigma j and the pol- 

 linia suspended, attached in pairs (one of each adjacent cell of different 

 anthers) to the corpuscle or gland. 



* Hoods (the cucullate or hollowed nectariferous appendages of the crown) cristate- or 

 corniculate-appendaged within. 



1. Asclepiodora. Corolla rotate-spreading in anthesis. Hoods basilar, inserted over 



the whole very short column, spreading and arcuate-assurgent, little surpassing the 

 anthers, slipper-shaped and the rounded apex fornicate, hollow and with a thickish 

 fleshy back, traversed by a salient crest which near the apex divides the cavity. 

 Anther-wings narrowed at base, angulate above the middle if at all. Leaves com- 

 monly alternate. 



2. Asclepias. Corolla almost always reflexed in anthesis. Hoods involute or compli- 



cate, not fornicate, bearing a horn or crest-like process from the back or toward the 

 base within, either sessile next the corolla or elevated on a column which is shorter 

 than the anthers. Anther-wings widening down to the base, usually triangular, the 

 salient base being truncate or semi-hastate, or broadly rounded. Leaves opposite or 

 varying to alternate or verticillate. 



* * Hoods wholly destitute of crest or appendage within. 



3. Acerates. Hoods involute-concave or somewhat pitcher-shaped. Anther-wings 



widened or angulate if at all near or above the middle, thence narrowed to the base. 

 Otherwise as Asclepias. Leaves alternate or scattered. 



1. ASCLEPIODOEA, Gray. 



Low and stout perennial herbs, often decumbent : flowers large : corolla 

 lobes ovate, greenish : follicles usually bearing some scattered soft-spinulose 

 projections, on recurved or sigmoid pedicels. Distinguished from Asclepias 

 by the hood bearing a crest instead of a horn. Proc. Am. Acad. xii. 66. 



1. A. decumbens, Gray. Scabrous-puberulent : leaves from lanceolate 

 to linear, tapering to the apex : umbel solitary : corolla depressed-globular in 

 bud, hardly twice the length of the yellowish or dark-purplish hoods, which 

 overtop the somewhat depressed anther-column : anther-wings salient, espe- 



