700 MISC. PUBLICATION 42 3, IT. S. DEPT. OF AGRICULTURE 



7. Scales prominent, commonly exserted; corolla lobes triangular to 



sublanceolate, acute, reflexed with inflexed tips; capsules mostly 



depressed-globose, 2- to 4-seeded 2. C. campestris. 



6. Corolla lobes ovate or suborbicular, obtuse (8). 



8. Flowers about 2 mm. long, subsessile, in few-flowered glomerules; 



margins of the perianth lobes denticulate; calyx lobes orbicular, 

 broadly overlapping; capsules conic, mostly 1-seeded. 



7. C. DENTICULATA. 



8. Flowers mostly much larger, pedicellate, in many-flowered, cymose 

 clusters; calyx lobes ovate, obtuse; capsules globose-ovoid, 



mostly 3- or 4-seeded 8. C. gronovii. 



1. Capsules circumscissile, i. e., easily separating near the base in a more or less 



regular line of cleavage (9) . 



9. Styles subulate, commonly much thicker at base; calyx lobes commonly 



more or less carinate (10). 



10. Flowers mostly 3 to 5 mm. long; styles pronouncedly subulate, becoming 



subconic in fruit 9. C. mitraeformis. 



10. Flowers mostly about 3 mm. long; styles subulate but not becoming conic 



in fruit; perianth lobes more or less irregularly denticulate, thickened 



medianally to form a carina 10. C. erosa. 



9. Styles more slender, mostly about equally thick throughout but some- 

 times slightly thicker near the base (11). 



11. Scales dentate only toward the apex (12). 



12. Flowers whitish when dry, more or less granulate- or scabrous-papillate; 

 calyx lobes broad, ovate-deltoid, short-acute; scales bridged below 

 the middle 12. C. odontolepis. 



12. Flowers reddish when dry, smooth; calyx lobes triangular, acute, com- 



monly somewhat thickened in the center to form a low carina; 



scales bridged near the middle 13. C. dentatasquamata. 



11. Scales fimbriate (13). 



13. Calyx one-half to three-fourths as long as the cylindric corolla tube, 



the lobes triangular to sublanceolate, acute, often carinate; scales 

 reaching to about the middle of the corolla tube. 



15. C. TTTBERCULATA. 



13. Calyx equaling or surpassing the campanulate corolla tube; scales 

 reaching the filaments; capsules mostly quickly and definitely 

 circumscissile (14). 

 14. Lobes of the calyx triangular-ovate, obtuse, commonly carinate; 



pedicels short or almost none 11. C. applanata. 



14. Lobes of the calyx triangular-ovate-lanceolate, acute to acuminate; 

 pedicels definite, often as long as or longer than the flowers, these 

 in loose umbellate cymes 14. C. tjmbellata. 



1. Cuscuta cephalanthi Engelm., Amer. Jour. Sci. 43: 336. 1842. 

 Apparently rare in Arizona, where collected in the southern part of 



the State by Wright without indication of definite locality, probably 

 in Cochise County. Massachusetts to Oregon and south to Mexico, 

 infrequent westward. 



Host genera numerous, including Salix, Spiraea, Vicia, Draco- 

 cephalum, Teucrium, Cephalanthus, Solidago, Aster, Sonchus. This 

 species is often confused with C. gronovii, to which it bears some 

 resemblance. It is distinguished by the mostly 3- or 4-parted flowers 

 and the persistence of the corolla at the top of the Gapsule instead of 

 about it or at base, as with C. gronovii. The capsule is subglobose 

 rather than conic as in that species. 



2. Cuscuta campestris Yuncker, Torrey Bot. Club Mem. 18: 138. 



1932. 



Cuscuta pentagona var. calycina Engelm., Amer. Jour. Sci. 45: 



76. 1845. 

 Cuscuta arvensis var. calycina Engelm., Acad. Sci. St. Louis 

 Trans. 1: 495, 1859, 



