APOCYNACEAE. 
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Order 43. ASCLEPIADALES. 
Styles united; stamens distinct or gynandrous; pollen loosely granular. 
109. Apocynaceae. 
Styles distinct; stamens monadelphous; pollen united into waxy masses or the 
grains in groups of 4. no. Asclepiadaceae. 
Family 109. APOCYNACEAE Lindl. Dogbane Family. 
Anthers unappendaged at the base, not connected with the stigma; flowers without 
a disk; leaves alternate. 1. Amsonia. 
Anthers appendaged at the base, converging around the stigma and slightly 
adhering to it; calyx-tube partly attached to the gynoecium by the thick disk ; 
leaves opposite. 2. Apocynum. 
1. AMSONIA Walt. 
1. Amsonia texana (A. Gray) Heller. (A. angustifolia texana A. Gray) 
In rocky places from Texas to Colo.—Grand Junction. 
2. APOCYNUM L. Dogbone, Indian Hemp. 
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. 2. A. scopulorum. 
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. 3. A. lividum. 
Leaves perfectly glabrous. 4. A. ambigens. 
Corolla less than twice as long as the calyx; its lobes erect or nearly so. 
Leaves acute at the base, petioled. 5. A. cannabinum. 
Leaves, at least those of the main stem, truncate or subcordate at the base and 
subsessile. 6. A. hypericifolium. 
1. Apocynum androsemaefolium L. In copses and borders of woods from 
Anticosti and Ida. to Ga. and Ariz.—Alt. 7000-9500 ft.—Artist’s Glen; Engel- 
mann Canon; Wahatoya Creek; mountains, Larimer Co.; Stove Prairie 
Hill; Horsetooth. 
2. Apocynum scopulorum Greene. In the mountains from Sask. and Yukon 
to Colo.—Alt. 5)000-9000 ft.—Pagosa Springs; Mancos; Roger’s, Gunnison 
watershed. 
3. Apocynum lividum Greene. In the mountains of Colo.—Alt. 5000-8000 
ft.—Black Canon; mouth of Cheyenne Canon; Mancos ; Piedra ; Palisade; 
Clear Creek Canon; Ft. Collins. 
4. Apocynum ambigens Greene. In the mountains from Mont, and Wash, 
to Colo, and Calif.—Alt. 6000-9000 ft.—West of Ouray; Black Canon; 
Boulder Canon; Rist Canon; Horsetooth Mountain; Montrose; Steamboat 
Springs. 
5. Apocynum cannabinum L. On banks of streams from Anticosti and 
Wash, to Fla. and L. Calif.—Alt. 4000-5000 ft.—Deer River; New Windsor, 
Weld Co.; Boulder; along the Poudre; Ft. Collins. 
6. Apocynum hypericifolium Ait. In sandy soil from Ont. and B. C. 
to Ohio and N. M.—Alt. 5000-6000 ft.—Plains and foot-hills near Boulder. 
