Rydberg : Studies ox the Rocky Mountain Flora 501 



navian P. farinosa in the longer bracts, in the longer calyx and 

 in the short corolla lobes. The specimens of northeastern America 

 seem to be like the European plant. In the latter the bracts arc 

 only 4—6 mm. long, acuminate, the calyx less than three fourths 

 the length of the tube of the corolla and the lobes of the latter 

 4—5 mm. long. P. Americana grows in swamps and wet meadows 

 of the Rocky Mountain region at an altitude of 1200-2500 m. 



Montana: Deer Lodge, 1895, P. A. Rydberg, 2-/^6 (type). 



Wyoming: Little Laramie River, \'i<^6, Avcn Nelson, ig6i ; 

 Hams Fork and La Barge, 1900, C. C. Ciirtis. 



Alberta: Devil's Head Lake, Banff, 1899, W. C. McCalia, 



2J.22. 



Colorado: North Park, 1896, Geo. E. Osterhotit. 



Cuscuta gracilis sp. nov. 



Stem filiform, about .25 mm. in diameter. Flowers in dense 

 globular clusters : calyx gamosepalous but cleft to near the 

 base, lobes ovate : corolla urceolate, less than 2 mm. high, lobes 

 ovate, widely spreading, acute, delicate, about i mm. long ; scales 

 ovate, crenate, not divided, almost half as long as the corolla-tube: 

 filaments subulate, about twice as long as the anthers : styles dis- 

 tinct, equal, about as long as and somewhat thicker than the red 

 filiform curved stigmas : capsule about 2 mm. high, acute-globose, 

 circumscissile near the base : seeds about i mm. long. 



This species is nearest related to C. epilinuni, which, however, 

 has shorter and broader corolla-lobes, shorter filaments, scarcely 

 longer than the anthers and short emarginate and crenate scales. 

 C. gracilis grows parasitic on species of Erigeron, Chrysothannins 

 and Solanuvi. 



Wyoming : Rolling plains between Sheridan and Buffalo, 1900, 

 F. Tweedy, 32^2 (type) ; Laramie, 1894, Aveji Nelson, iijg. 



Cuscuta megalocarpa sp. nov. 



Stem stout, usually over i mm. in diameter. Flowers in dense 

 globular clusters : pedicels very short, at most 2 mm. long : 

 calyx gamosepalous, lobes rounded, scarcely i mm. long : corolla 

 about 3 mm. high and broad, lobes broadly triangular, acutish, 

 about I mm. long, with incurved tip ; fringed scales attached near 

 the bottom, equalling about half the corolla-tube, deeply 2-lobed, 

 and fringed only in the open sinuses : stamens about as long as the 

 lobes of the corolla, filaments subulate, about twice as long as the 



