CUSCUTACEAE. 273 



4. Cuscuta curta Engelm. (C. Gronovii curta Engelm.) On coarse herbs 

 in sandy soil in Utah and Colo. — Alt. about 7000 ft. — Dome Rock in Platte 

 Canon. 



5. Cuscuta indecora Choisy. On herbs, mostly composites and leguminous 

 plants, commonest on Ambrosia artemisiaefoUa and Glycyrrhiza lepiota; 

 from Ills, and Neb. to Fla. and Calif. — Alt. 4000-5000 ft. — Ft. Collins. 



6. Cuscuta megalocarpa Rydb. On willows ; in Colo, and Wyo. — Alt. 

 about 7000 ft. — Cucharas Creek near La Veta. 



7. Cuscuta cuspidata Engelm. On Ambrosia, Iva and some leguminous 

 plants from Mo. and Neb. to Tex. and Colo. — Alt. 4000-5000 ft. — Ft. Collins. 



Family 112. CONVOLVULACEAE Vent. Morning-glory Family. 



Styles distinct, each 2-cleft. i. Evolvulus. 

 Styles united up to the stigmas. 



Stigmas ovoid or subglobose. 2. Ipomoea. 



Stigmas filiform to oblong-cylindric. 3. Convolvulus. 



I. EVOLVULUS L. 



I. Evolvulus Nuttallianus R. & S. (£. argenteus Pursh; not R. Br.; E. 

 pilosus Nutt. ; not Lam.) In sandy soils and on sterile plains from S. D. and 

 Colo, to Tex. and Ariz. ; also Mex. — Alt. 4000-6000 ft. — Canon City ; along 

 Platte River, Denver; Fossil Creek, Larimer Co.; Trinidad; Ft. Collins; near 

 Boulder; Ouray; Dixon Canon. 



2. IPOMOEA L. Morning-glory. 



T. Ipomoea leptophylla Torn On plains and hillsides from S. D. and 

 Wyo. to Tex. and N. M. — Alt. 4000-5000 ft. — Denver ; Rocky Ford ; bank of 

 Arkansas River. 



3. CONVOLVULUS L. Wild Morning-glory, Bindweed. 



Bracts small, remote from the calyx. 



Plant not canescent ; leaf-blades hastate, but otherwise entire. 



Whole plant glabrous or nearly so. i. C. arvensis. 



Stem and lower surface of the leaves with scattered long hairs. 



2. C. amhigens. 

 Plant more or less canescent ; leaves usually lobed or dissected. 



Main divisions of the leaf-blades ovate or oblong, obtuse, lobed. 



3. C. hermaiinioides. 

 Main divisions of the leaf-blades linear, entire ; the basal lobes usually cleft 



deeply. 4. C. incanus. 



Bracts large, close under the calyx and enclosing it. 



Leaf-blades hastate ; the basal lobes often sinuate-dentate, acute ; stem and 



leaves glabrous or slightly hairy. 5. C. americanus. 



Leaf-blades more sagittate ; basal lobes rounded, entire ; stem and leaves 

 densely pubescent. 6. C. interior. 



1. Convolvulus arvensis L. Naturalized from Europe, growing in fields 

 and waste places from N. S. and Mont, to N. J. and Colo. — Durango. 



2. Convolvulus ambigens House. In loose or sandy soil from Colo, to N. M. 

 and Calif. — Alt. 5000-6000 ft. — Plains near Boulder; Ft. Collins. 



18 



