APOCYNACEAE 



Sepals subulate, long-attenuate, 24 mm. long; pod more or less torulose or con- 

 stricted around the seeds. 



Leaves ovate or those of the branches lanceolate. 2. A. brevifolia. 



Leaves narrowly lanceolate, those of the branches linear. 3. A. Eastwoodiana. 

 Plant densely villous. 4. A. tomentosa. 



1. A. latifolia M. E. Jones. Perennial, with a woody base; stems several, 

 2-5 dm. high, glabrous; leaves ovate to lanceolate, acute or acuminate, 3-5 cm. 

 long, sessile; corolla lead-purple, about 15 mm. long; lobes oblong, two-thirds 

 as long as the tube; follicles about 4 cm. long, 3^4 mm. thick, not torulose. A. 

 texana Rydb. (Fl. Colo.). Clayey or alkaline soil: w Colo. Utah Ariz. Son. 



2. A. brevifolia A. Gray. Perennial, often with a woody base; stem gla- 

 brous, 3-5 dm. high; leaves thick; corolla about 1.5 cm. long, constricted at the 

 mouth, and bearded within the throat; lobes ovate or oblong, half as long as the 

 tube; follicles 5-7 cm. long, thickish. Arid regions: Utah Ariz. Calif. Son. 

 My-Je. 



3. A. Eastwoodiana Rydb. Perennial, with a short woody base; stem 3-5 

 dm. high; leaves 3-5 cm. long; corolla 16-20 mm. long; tube narrowly trumpet- 

 shaped; lobes nearly 4 mm. long; follicles 5-8 cm. long, about 8 mm. thick, often 

 breaking off between the seeds. In canons of desert regions : Utah Ariz. Son. 

 Je-Jl. 



4. A. tomentosa Torr. Perennial, with a woody base; stems 2-4 dm. 

 high, villous; leaves cinereous-villous, lanceolate to linear, sessile, 3-5 cm. long; 

 calyx-lobes subulate, about 3 mm. long; corolla about 15 mm. long, contracted 

 at the throat, which is bearded within; lobes oblong, half as long as the tube; 

 follicles 7-8 cm. long, not torulose. Sandy plains: Tex. s Utah Ariz. L. Son. 



2. APOCYNUM (Tourn.) L. DOGBANE, INDIAN HEMP. 



Perennial herbs with branched stems. Leaves opposite, entire. Flowers 

 in corymbose cymes. Sepals 5. Corolla campanulate; tube with five small 

 appendages, alternating with the stamens; lobes 5. Stamens adnate to the base 

 of the corolla-tube; anthers sagittate, at least coherent to the stigma. Follicles 

 2, slender. Seeds numerous, tipped with a long coma. 



Corolla fully twice as long as the calyx; its lobes spreading in anthesis. 

 Leaves more or less pubescent beneath. 



Sepals broadly lanceolate; corolla open campanulate; leaves thick, dark green, 



decidedly pubescent beneath. - 



Leaves oval, acute at both ends; plant usually tall. 1. A. androsemaefolium. 

 Leaves more or less ovate, rounded, truncate, or cordate at the base'; plant low, 



diffuse. 

 Leaves rounded, rarely truncate at the base; stem and branches glabrous. 



2. A. scopulorum. 

 Leaves subcordate or at least truncate at the base; stem and branches 



mostly pubescent. 3. A. pumilum. 



Sepals narrowly lanceolate; corolla narrower, almost cylindro-campanulate; leaves 

 pale green, pubescent merely on the petioles and the veins beneath, the lower 

 truncate, the upper acute at the base. 4. A. lividum. 



Leaves perfectly glabrous. 



Leaf-blades lanceolate or rarely ovate, pale; corolla almost white, narrowly cam- 

 panulate. 5. A. convallarium. 

 Leaves broadly or rounded ovate, thicker and dark green; corolla rose-colored, 



open campanulate. 



Sepals acute; corolla 5-6 mm. long. 6. A. ambigens. 



Sepals acuminate; corolla 7-9 mm. long. 7. A. macranthum. 



Corolla less than twice as long as the calyx; its lobes erect or nearly so. 



Leaves acute at the base, petioled. 8. A. cannabinum. 



Leaves, at least those of the main stem, truncate or subcordate at the base and sub- 

 sessile. 9. A. sibiricum. 



1. A. androsaemifolium L. Stem erect, 3-15 dm. high, glabrous; leaf- 

 blades 4-10 cm. long, pale beneath; calyx-lobes ovate, acuminate, scarcely 1 

 mm. long; corolla pink; tube 4-5 mm. long; lobes ovate, obtuse. Thickets and 

 fields: Anticosti Ga. Ariz. Ida. B.C. Plain Mont. Je-Jl. 



2. A. scopulorum Greene. Stem 3-6 dm. high, glabrous; leaf -blades ovate, 

 rounded or truncate at the base, 3-6 cm. long, thick, dark green above, pale 

 beneath; calyx-lobes lanceolate, acute or somewhat acuminate, 1.5-2 mm. long; 



