137] NORTH AMERICAN AND WEST INDIAN CUSCUTA—YUNCKER 47 



Section clistogrammica Engelmann 



Cuscuta section Clistogrammica Engelmann, Trans. Acad. Sci. St. Louis, 1:491, 1859. 



Capsule not circumscissile. Flowers with or without numerous suli- 

 tending bracts. The species belonging to this section are those most 

 commonly found in the United States, A small number of them are found 

 in Canada, Mexico and the West Indies. 



Key to the subsections 

 Flowers not subtended by bracts (sometimes present at the base of the flower cluster in 



C. denticulata); calyx segments more or less united platycarpae (p. 47). 



Flowers subtended by numerous bracts; calyx segments mostly free. . .lepidanche (p. 72). 



Subsection platycarpae Engelmann 

 Cuscuta § Platycarpae Engelmann, Trans. Acad. Sci. St. Louis, 1 :491, 1859. 

 Cuscuta § Oxycarpae Engelmann, Trans. Acad. Sci. St. Louis, 1:499, 1859. 



Flowers membranous or fleshy, mostly pedicellate, not subtended by 

 numerous bracts (in C. denticulata one or two bracts may be present at 

 base T)f the flower cluster). 



Key to the species 

 Capsule globose, more or less depressed (pointed in C. decipiens and C. indecora) ; flowers mem- 

 branous or fleshy; scales present. 



Flowers mostly smooth, not particularly fleshy or papillate except in one variety. 

 Corolla remaining at the base of the mature capsule. 



Corolla lobes obtuse; scales reaching the filaments; pentamerous 



C glandulosa (p. 48) . 



Corolla lobes triangular, acute; scales reduced to a few processes about the apex; 



mostly tetramerous C. polygonorum (p. 49). 



Corolla lobes acute, with inflexed tips; scales prominent; pentamerous. 



Flowers about 2-3 mm. long, scales rather deeply fringed, exceeding the 



length of the tube C. pentagona (p. 50). 



Flowers 2.5-5 mm. long, scales rather shallowly fringed, not reaching the 



filaments C. plaUensis (p. 53). 



Corolla carried at the apex of the capsule like a hood; mostly tetramerous 



C. cephalanthi (p. 53) 



Corolla surrounding the capsule; calyx lobes not overlapping; pentamerous. 



Calyx lobes not reaching the middle of the corolla, deltoid 



C racemosa chiliana (p. 54). 



Calyx lobes usually exceeding the middle of the corolla, ovate 



C. decipiens (p. 55). 



Flowers fleshy, cells more or less lens shaped giving the flowers a slightly papillate 

 appearance, tips of corolla lobes inflexed. 



Flowers mostly tetramerous; scales rudimentary, represented by toothed wings 



C coryli (p. 55). 



Flowers mostly pentamerous; scales prominent C. indecora (p. 57). 



Capsule globose or conic; scales represented by very short bridges and the slight beginning of 

 a wing along the stamen attachent in some specimens. 



Flowers fleshy, papillate; corolla lobes less than half as long as the corolla tube 



C. jepsonii (p. 59). 



Flowers not fleshy; corolla lobes greater than half as long as the corolla tube 



C californica (p. 60). 



