APOCYNACEAE (DOGBANE FAMILY) i8i 



APOCYNACEAE (Dogbane Family) 



Herbs, perennial; juice milky. Leaves simple, entire, opposite; 

 stipules none. Flowers perfect, regular, the parts in 5's. Calyx 

 persistent. Corolla gamopetalous, lobed. Stamens on the corolla, 

 as many as its lobes, alternate with them. Carpels 2, distinct, 

 superior, adherent to the calyx at base; ovules many. Fruit of 

 2 foUicles. Seed bearded. — Only the following genus. 



APOCYNUM (Dogbane) 



Anthers united around the stigma. — (Gk. apo = from, kyon = a dog ; 

 some species are said to be poisonous to dogs.) 



A. Leaves oval to orbicular; corolla lobes spreading or recurved. 



B. Leaves glabrous. W. E. A. androsaemifoUum (spreading dogbane) 

 BB. Leaves puberulent. E. A. detonsum 



AA. Leaves oval to lanceolate; corolla lobes erect. 



C. Calyx and bracts ciliolate. E. A. ciliolatum 

 CC. Calyx and bracts entire, not ciliolate. 



D. Cymes large, many-flowered. E. A. cannabinum (Indian hemp) 



DD. Cymes small, few-flowered. E. A. suksdorfil 



ASCLEPIADACEAE (Milkweed Family) 



Herbs, perennial; juice milky. Leaves opposite or whorled; 

 stipules none. Flowers regular, perfect, in umbels. Calyx seg- 

 ments 5. CoroUa rotate to funnelform, 5-lobed or -cleft. Crown 

 between stamens and corolla 5-lobed or -parted. Stamens 5, on 

 toroUa near base; filaments monadelphous; ahthers united around 

 the stigma. Carpels 2, superior, their ovaries and styles distinct, 

 their stigmas united into a head. Fruit of 2-follicles. Seeds many, 

 flatfish, long-bearded. 



A. Leaves cordate-clasping at base; hoods of the crown between stamens and 

 corolla without horns inside. U. — (Gk. u, = without, kerates = horns; they 

 lack the stamen horns of Asdepias.) Acerates cordifolia (green milkweed) 



AA. Leaves not clasping; hoods of the crown between stamens and corolla each 

 with a horn inside. ASCLEPIAS (p. 181) 



ASCLEPIAS (Milkweed) 



Leaves entire. — (The Greek name of the god of healing; some of the 

 plants are medicinal.) 



A, Leaves white-tomentose; stem 6-18 dm. high; leaves oval to oblong. E. 



A, speciosa (woolly milkweed) 

 AA. Leaves glabrous; either the stem only 1.5-3 dm. high or else the leaves linear to 

 lanceolate. 



