1 66 UNIVERSITY OF MISSOURI STUDIES [314 



Plains about Boulder, especially on the banks of irrigation 

 ditches, 5100-6000 ft. (Daniels, 391). 



MISSOURI to SOUTH DAKOTA and COLORADO; ALABAMA to 

 ARIZONA. 



271. POINSETTIA Graham. 



674. P. cuphosperma (Engelm.) Small [Euphorbia cuphos- 

 perma . Boiss.]. WARTY SPURGE. 



Plains east of Boulder and along railroads, 5100-6000 ft. 

 (Daniels, 692). Tenth Street, Boulder (Cockerell). 



SOUTH DAKOTA to WYOMING ; TEXAS to ARIZONA and MEX- 

 ICO. 



675. P. dentata (Michx.) Small [Euphorbia dentata Michx.]. 

 TOOTHED SPURGE. 



On the plains and mesas, frequent, 5100-6000 ft. (Daniels, 



430- 



PENNSYLVANIA to SOUTH DAKOTA ; LOUISIANA to UTAH and 

 MEXICO. 



Family 66. CALLITRICHACEAE Lindl. Water starwort 



family. 



272. CALLITKICHE L. WATER STARWORT. 



676. C. palustris L. MARSH WATER STARWORT. 



Aspen bog, Glacier Lake; also in streams and ponds about 

 Boulder, 5100-9000 ft. (Daniels, 248). Eldora lake (W. W. 

 Robbins). 



NOVA SCOTIA to BRITISH COLUMBIA; FLORIDA to CALIFOR- 

 NIA: EUROPE: ASIA: SOUTH AMERICA. 



677. C. bifida (L.) Morong [C. autumnalis L.]. AUTUMNAL 



WATER STARWORT. 



South Boulder creek, Arapahoe Road, common; in com- 

 pany with the preceding species, but more abuncant, 5200-5400 

 ft. (Daniels, 738). Not in Rydberg's Flora. 



QUEBEC to MANITOBA and OREGON ; MICHIGAN to COLORADO. 



