CUSCUTACEAE (DODDER FAMILY) 391 



5. Cuscuta arvensis Beyrich, Hook. Fl. Bor. Am. 2: 77. 1834. Stems 

 pale and slender, low; flowers sessile or nearly so, small, about 2 mm. long: 

 calyx-lobes obtuse, broad: corolla-lobes acuminate, longer than the tube, 

 the tips inflexed ; scales large, deeply fringed all around with irregular fila- 

 ments: ovary and capsule depressed-globose, its base encircled by the wither- 

 ing corolla : styles not longer than the capsule. Not frequent ; various low plants 

 as hosts; from our range to the Atlantic States. 



6. Cuscuta Polygonorum Engelm. Am. Journ. Sci. 43: 342. 1842. Stems 

 coarse, orange-yellow: flowers crowded, sessile: calyx 4-5-lobed; its lobes 

 ovate-acute: corolla-lobes triangular-ovate, as long or longer than the tube; 

 scales reduced, 2-cleft, or often nearly wanting: capsule depressed-globose, 

 the withering corolla persistent at its base. On Polygonum and other 

 herbs. 



7. Cuscuta plattensis A. Nels. Bull. Torr. Bot. Club 26: 131. 1899. Stems 

 yellowish-green, moderately slender: flowers in either loose or dense panicu- 

 late cymes, short-pediceled : calyx-lobes obtuse, suborbicular, somewhat ex- 

 ceeding 1 mm. in length, the tube very short: corolla marcescent at the base 

 of the capsule; the lobes short-ovate, obtuse, about half the length of the 

 broadly campanulate tube; tube about 2 mm. long; scales shorter than the 

 tube, broadest at the truncate fringed summit: styles distinct, but slightly 

 unequal, scarcely more than 1 mm. in length and not more than one fourth 

 the length of the mature capsule: capsule subglobose, 5 mm. in diameter. 

 On Grindelia, Solidago, and Helianthus; Wyoming. 



8. Cuscuta Cephalanthi Engelm. Am. Journ. Sci. 43: 336. 1842. Stems 

 coarse and yellow, mostly high-climbing: flowers in paniculate, often com- 

 pound cymes, very small, about 1.5 mm. long, on short thick pedicels, often 

 4-merous : calyx-lobes obtuse : corolla cylindric-campanulate ; the lobes obtuse, 

 half as long as the tube ; scales shorter than the tube, irregularly fringed around 

 the summit: capsule depressed-globose; styles slender, as long as the ovary, 

 the marcescent corolla capping the large capsule. On tall herbs and shrubs. 



9. Cuscuta indecora Choisy, Mem. Soc. Gen. 9: 278. 1842. Stems coarse: 

 flowers 3 mm. long, cymose, rather long-pediceled : calyx-lobes 5, ovate- 

 lanceolate, acute: corolla campanulate; the lobes subcrenate, triangular, as 

 long as the tube, spreading but with inflexed tips; scales ovate, irregularly 

 fringed all around: capsule oblong, acute. On low herbs and shrubs; fre- 

 quent on alfalfa. 



10. Cuscuta Coryli Engelm. Am. Journ. Sci. 43: 337. 1842. Stems coarse: 

 flowers about 2 mm. long, in cymes, on pedicels of variable length: calyx 

 4-5-lobed; the lobes triangular-acute, as long as the corolla-tube: corolla 

 campanulate; the lobes crenulate, acute, about as long as the tube, the tips 

 inflexed; scales small, oval, fringed on the sides sparingly or not at all: cap- 

 sule pointed, longer than the styles, covered or capped by the withered corolla. 

 On hazels and other shrubs. 



11. Cuscuta megalocarpa Rydb. Bull. Torr. Bot. Club 28: 501. 1901. 

 Stem stout, usually over 1 mm. in diameter: flowers in dense globular 

 clusters; pedicels very short, at most 2 mm. long: calyx gamosepalous, lobes 

 rounded, scarcely 1 mm. long: corolla about 3 mm. high and broad; lobes 

 broadly triangular, acutish, about 1 mm. long, with incurved tip; fringed 

 scales attached near the bottom, 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 rounded anthers: style distinct, short; stigmas 

 capitate: capsule 5-6 mm. in diameter, acute- globose, about 4-seeded. On 

 willows and other shrubs; Colorado and Wyoming. 



12. Cuscuta umbellata H.B.K. Nov. Gen. & Sp. 3: 121. 1815. Stems low 

 and capillary: flowers 3-4 mm. long, few together in umbel-like clusters, 

 usually shorter than their pedicels: acute calyx-lobes and lanceolate-subulate 

 lobes of the corolla longer than its shallow tube: scales deeply fringed and 

 exceeding the tube: capsule more or less regularly circumscissile, usually 

 capped by the remains of the corolla. Dry places, on low herbs (Portulaca, 

 etc.) ; Colorado and southward. 



