133] NORTH AMERICAN AND WEST INDIAN CUSCUTA—YUNCKER 43 



Cuscuta umhellata dubia n. var. 

 [Figure 9 f-g] 



Stems very slender. Flowers about 2 mm. long; calyx lobes triangular, 

 acute, forming angles at the sinuses; corolla lobes about equal to the tube, 

 spreading, triangular-oblong, acute. 



This specimen, which is fragmentary, appears to be distinct. The 

 stems are the most slender seen in any of the species. 



Type locality: Guaymas, Sonora, Mexico. 



Specimens examined: Mexico: Sonora; Guaymas, on the sea beach (Palmer 1209, the 

 type, in the U. S. Nat. Herb, as sheet 474,815). •• 



Cuscuta gracillima Engelmann 

 C. gracillima Engelmann, Trans. Acad. Sci. St. Louis, 1 :488, 1859. 



Stems very slender, disappearing early from between the flower clusters. 

 Flowers smooth or papillate, about 2 mm. long, on pedicels sometimes 

 shorter but mostly longer than the flowers, in dense clusters; calyx tur- 

 binate; lobes triangular, lanceolate, acute to acuminate, longer than the 

 tube of the corolla; corolla campanulate; lobes about as long as or slighty 

 longer than the tube, triangular to lanceolate, acute; scales ovate, fringed, 

 longer than the tube, or much reduced, bridged at about or below the 

 middle; stamens longer or shorter than the lobes; filaments slender; anthers 

 oblong, oval, somewhat versatile; ovary small, globose; styles capillary, 

 many times the length of the ovary. Capsule tardily and irregularly 

 circumscissile, depressed-globose, thin; seeds about 1 mm. long, one to four 

 in a capsule, ovate, somewhat oblique; hilum oblong, oblique. 

 Cuscuta gracillima subtilis (Chaubard) n. comb. 

 [Figures 1 7 a-e and 82] 

 C.foetida Hooker & Arnott, Bot. Beechy Voy., p. 304, 1838; not HBK, 1818. 

 C. subtilis Chaubard in Engelmann, Trans. Acad. Sci. St. Louis, 1:489, 1859; in synon. 



Flowers glabrous, pentamerous; scales well developed; stamens longer 

 than the corolla lobes ; the typical variety of the species. 



Type locality: Mexico. Range: Central Mexico. 



Specimens examined: Mexico: A fragment of the tj'pe in the Engelmann Herb. 

 Jalisco; Manzanillo (Palmer 949). Sinaloa; Mazatlan (Wright 1264, Rose, Standley & 

 Russell 13727a, 13804). Morelos; Cuernavaca (Pringle 6189), valley near Yautepic (Pringle 

 8716). 



Cuscuta gracillima esquamata n. var. 



Flowers frequently tetramerous; scales lacking or reduced to but a 

 few short processes; corolla somewhat glandular. 



Type locality: El Taste, Lower California, Mexico. 



Specimens examined: Mexico: Lower California; El Taste (Brandegee in 1893, the 

 type, in the Univ. California Herb.) 



Cuscuta gracillima saccharata Engelmann 

 [Figures 17 f-g and 81] 

 C. gracillima saccharata Engelmann, Trans. Acad. Sci. St. Louis, 1 :489, 1859. 

 C. sidarum Liebmann in Engelmann, Trans. Acad. Sci. St. Louis, 1:489, 1859; in synon. 



