386 ASCLEPIADACEAE (MILKWEED FAMILY) 



corolla greenish-white, 3-3.5 mm: long; lobes erect or nearly so: follicles 

 12-15 cm. long. — Throughout the United States. 



2a. Apocyntim cannabinumlividum (Greene) A. Nels. Habit; size; and 

 leaf characters the same, glabrous:, ealyx-lobes only half as long as the nar- 

 rowly campanulate corolla, i {A. lividym Greene, PI. B9,ker. 16. ,1901.)— 

 Wyoming and Colorado. 



3. Apocynum hypericifoliimi Ait. Hort. KeW 1 : 304. 1789. Not strongly 

 differentiated from A. cannabinum: leaves usually broader, with rounded or 

 subcordate base, subsessile, often abruptly apiculate. — New Mexico, to Mon- 

 tana and the Great Lakes. 



95. ASCLEPIADACEAE Lindl. Milkweed Family 



Mostly herbs with milky juice, usually opposite leaves without stipules, 

 and regular perfect flowers in terminal or pseudo-axillary or sometimes axil- 

 lary cymes (often imibelliform): Calyx free from the ovary or nearly so, im- 

 bricated in the bud. Corolla 6-merous, convolute, or often nearly valyate 

 in the bud. ' Stamens 5, borne on the tube of the corolla and alternate with 

 its 1 lobes; anthers surrounding the stigina; pollen in 1 or 2 waxy masses, in 

 ours all the pollen in each cell in one mass and attached to th,e stigmatic 

 disk by the glands that alternate with the anthers. A crown of 5 parts or 

 lobes usually present .between the corolla and the mostly monadelphqus 

 stamens, and adhate either rto the one or the other. Ovary, of 2 cells that 

 become severs,! to many-seeded foUibles. Seeds almost always' bearing la 

 long and soft coma. , , "'' 



Lobes of the' corolla reflexed kt aii^hesis. '■,.. 



Leaves alternate or opposite: Hoods of the crpwn crestless > .. ,r ^^ 1. Aceratea.,i?, ^v 



Leaves mostly opposite; hoods of the crown each with an incurved hdrzi 2. Asclepiaa. ' ' 

 Lobes of the corolla erect at anthesis; leaves alternate; hoods of the 



crown prominently crested 3. Asclepiodoia, 



• t'-,i'.', yOO'u, 



1. ACERATES E\l, Green Milkweed 



Perennial herbs, with thick leaves and green or purplish' flowers in short- 

 peduncled or sessile umbels. Calyx 5-partea or 5-dividea, the Segments acute, 

 glandular within. Corolla deeply 5-cleft, the segments valvate, reflexed in 

 anthesis. Crown-colurrin very* short; crown of 5 involute-concave or some- 

 what pitcher-shaped hoods, neither horned nor crested Within, or in one species 

 having a small interior crest arid usually a few small processes at the base of 

 the, anther-wings, forming an obscure inner crown. Stignia 5-lohed, 



Leaves numerous, alternate-scattered; auricles of tKe hoods conspicuous 1. A. auriculata. 

 Leaves in part opposite; auricleS:Of-the hoods concealed.or.wantmg. , ,.,.,, 



Hoods entire 2. A. viridiflora. 



Hoods trilobed . . . . . . . . . 3. A. angustifolia. 



1. AceratesauriculataEngehh.Bot.Mex. Bound. 160. I859v' Glabrous up 

 to the inflorescence; steni 5-8 dm. high, slender: leaves linear-filiform, with 

 scabrous margins: umbels several, lateral: "column below the hoods very 

 short; hoods oval or quadrate, emarginately or sometimes 3-crehately trun- 

 cate, the involute margins at base appendaged with a pair of remarkably large 

 and- broad auricles: anther-wings narrow, and of equal, breadth from top, tp 

 bottom. — Colorado and Kansas to Texas and New Mexico, ' ' 



2. Acerates viridiflora (Raf.) Eaton,. Man. Ed. 5. 90. 1829. Tbmentose- 

 puberulent; stem 2-5 dm. high: leaves oval or oblong an J obtuse or refuse, 

 or sometimes narrower and acute: umjjels 2-5 or somejitnes solitary, dense, 

 mostly lateral and subsessile; pedicels little over twice the length of the re- 

 flexed narrow 1:' cl/.onc lobes of the greenish corolla; hoods somewhat fleshy. 



