ACERACEAE. 227 



I. Acer glabnim Torr. In canons, on hillsides and along streams, from 

 W. Neb. and Wyo. to N. M. and Utah. — Alt. 4000-9000 ft. — Headwaters of 

 Clear Creek; Hinsdale Co.; Pike's Peak; near Pagosa Peak; near La Plata 

 Post Office ; Idaho Springs ; foot-hills west of Ft. Collins ; South Cheyenne 

 Cation; Colorado Springs; Wahatoya Canon; Ute Pass; southeast of Ouray; 

 along Uncompahgre River near Ouray; Rist Cafion; Dillon Canon; gulch 

 west of Pennock's ; hills northwest of Soldier Caiion ; Howe's Gulch ; Baxter's 

 ranch ; Big Narrows on Poudre ; Ft. Collins ; Dolores ; North iPoudre River ; 

 Campton's ranch; Horsetooth Gulch; gulch west of Dixon Canon; Redstone; 

 mountains between Sunshine and Ward ; Eldora to Baltimore. 



M,. Acer grandidentatum Nutt. In wooded valleys and canons from Mont, 

 to Tex. and Ariz. — Pike's Peak. 



2. RULAC Adans. Box-elder, Ash-leaved Maple. 



Twigs and petioles essentially glabrous ; leaflets thin, coarsely toothed. 



1. R. Negundo, 

 Twigs and petioles copiously pubescent ; leaflets thick, lobed. 2. R. texana. 



1. Rulac Negundo (L.) Hitchc. {Acer Negundo L. ; Negundo acer aides 

 Moench.) In low ground and along streams from Vt. and Ida. to Fla. and 

 Tex. — Alt. 4000-7000 ft. — South Cheyenne Caiion; Colorado Springs. 



2. Eulac texanum (Pax.) Small. {Acer texanum Pax.) Along rivers from 

 Sask. and Mont, to Mo. and Ariz. — Alt. 5000-8500 ft. — Southeast of Ouray; 

 Cucharas Valley, near La Veta ; Ft. Collins ; Walsenburg ; Cache la Poudre ; 

 foot-hills near Boulder. 



Order 32. RHAMNALES. 



Sepals manifest ; petals involute ; fruit capsular or drupaceous ; ours shrubs or 



trees. 84. Frangulaceae. 



Sepals minute or obsolete ; petals valvate ; fruit a berry ; ours vines with tendrils. 



85. VlTACEAE. 



Family 84. FRANGULACEAE DC. Buckthorn Family. 



Fruit pulpy ; petals small, clawless or wanting ; stigmas usually i. 



1. Rhamnus. 

 Fruit dry; petals hooded and long-clawed; stigmas 3. 2. Ceanothus. 



I. RHAMNUS L. Buckthorn. 



Leaves broadly elliptic or ovate ; flowers solitary in the axils ; carpels 3 or 4. 



I. R. cathartica. 

 Leaves lanceolate ; flowers 2 or 3 in each axil ; carpels 2. 2. R. Smithii. 



1. Rhamnus cathartica L. Cultivated for hedges and escaped; native of 

 Europe. — Ft. Collins. 



2. Rhamnus Smithii Greene. Along streams in Colo, and N. Mex. — Alt. 

 about 7000 ft. — Pagosa Springs. 



2. CEANOTHUS L. New Jersey Tea. • 



Leaf-blades rounded-oval, often cordate at the base, very shining above ; closely 



glandular-dentate. 1. C. velutinus. 



Leaf-blades oblong to elliptic or ovate, glandular-serrate or sub-entire. 



