EUPHORBIACEAE. 225 



8. POINSETTIA Graham. SPURGE. 



Seeds not prominently tubercled ; glands of the involucre 3-4 ; leaf-blades linear 

 or linear-lanceolate. i. P. cuphosperma. 



Seeds prominently tubercled ; gland of the involucre solitary ; leaf-blades ovate 

 to lanceolate (linear-lanceolate only in one variety). 2. P. dentata. 



1. Poinsettia cuphosperma (Boiss.) Small. (Euphorbia cuphosperma Boiss.) 

 In canons and hillsides from S. D. and Wyo. to Tex. and Ariz. ; also Mex. 

 Alt. 5000-7000 ft. Colorado Springs; Manitou; Canon City. 



2. Poinsettia dentata (Michx.) Small. (Euphorbia dentata Michx.) In 

 moist soil from Pa. and S. D. to La., Mex. and Utah. Alt. 4000-6000 ft. 

 Boulder; Fort Collins; New Windsor. A rare variety with nearly linear 

 leaves. Fort Collins. 



Family 79. CALLITRICHACEAE Lindl. WATER STARWORT FAMILY. 

 i. CALLITRICHE L. WATER STARWORT. 



i. Callitriche palustris L. In shallow running water from N. S. and B. C. 

 to Fla. and Calif.; also Europe, Asia and S. Am. Leroux Parks, Delta Co.; 

 Ft. Collins; Boulder. 



Order 3 1 . SAPINDALES. 



Low annual herbs ; stamens twice as many as the sepals and petals. 



80. LlMNANTHACEAE. 



Shrubs or trees ; stamens usually as many as the petals or sepals. 

 Stamens opposite the sepals. 



Plants with resiniferous tissue ; fruit drupaceous ; seeds without aril ; leaves 



in ours compound. 81. SPONDIACEAE. 



Plants without resiniferous tissue ; fruit a loculicidal capsule ; seed with a 



fleshy aril; leaves simple. 82. CELASTRACEAE. 



Stamens alternate with the sepals ; fruit a double samara ; leaves opposite. 



83. ACERACEAE. 



Family 80. LlMNANTHACEAE Lindl. FALSE MERMAID FAMILY. 



i. FLOERKIA Willd. FALSE MERMAID. 



i. Floerkia occidentalis Rydb. In wet soil from Wyo. and Wash, to Colo. 

 and Utah. Steamboat Springs ; Gunnison Co. 



Family 81. SPONDIACEAE Kunth. SUMAC FAMILY. 



Drupe with glabrous outer coat ; stone ribbed ; plants poisonous to touch. 



1. RHUS. 

 Drupe with pubescent outer coat ; stone smooth ; plants not poisonous. 



2. SCHMALTZIA. 



i. RHUS L. POISON OAK, POISON IVY. 



i. Rhus Rydbergii Small. On plains, hills and among bushes from Mont, 

 and B. C. to Nebr. and Colo. Alt. 4000-5000 ft. Ft. Collins; foot-hills near 

 Boulder. 



15 



