ACERACEAE. 227 



1. Acer glabrum Torn 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 

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

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

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

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

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

 mountains between Sunshine and Ward ; Eldora to Baltimore. 



2. Acer grandidentatum Nutt. In wooded valleys and canons from Mont. 

 to Tex. and Ariz. — Pike's Peak. 



2. RULAC Adans. Box-elder, Ash-le.wed Maple. 



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



I. R. Negundo. 

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



1. Rulac Negundo (L.) Hitchc. (Acer Negundo L. ; Negundo aceroides 

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

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



2. Rulac 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. Fr.\.\gulace.'\e. 



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



85. VlT.\CEAE. 



Family 84. FRANGULACEAE DC. Buckthorn Family. 



Fruit pulpy ; petals small, clawless or wanting ; stigmas usually 2. 



I. Rhamnus. 

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



I. RHAMNUS L. Blxkthorx. 



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. i. C. vehttinns. 



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



