12. Cuscuta denticulata Engelm. 



Flowers about 2 mm. long, subsessile, in shortened more or less bracteate 

 inflorescences of few flowers; bracts often 1 to 3, ovate-lanceolate, acute; calyx 

 deeply divided; calyx lobes orbicular, obtuse to rx)unded at apex, denticulate, 

 overlapping to enclose the corolla tube; corolla campanulate, becoming urceolate 

 in fruit; corolla lobes ovate to oval, somewhat overlapping, spreading, about 

 equaling the tube; scales denticulate, about reaching the anthers, oblong-ovate, 

 bridged at about the middle or below; anthers oval, shorter than the corolla lobes, 

 about equal to the filaments; styles shorter than the small conic ovary; stigmas 

 small; globose; capsule conic, bearing the withered corolla about the top, mostly 

 1 -seeded. 



Ariz. (Mohave and Yuma cos.); s. Ut. to Calif, and w. Ariz. Parasitic on 

 Tamarix, Nicotiana and Hymenoclea. 



13. Cuscuta Gronovii R. & S. var. Gronovii. Fig. 641. 



Flowers mostly 2-3 mm. long from base to corolla sinuses, rarely smaller or 

 larger, commonly with few to many pellucid glandlike cells, with pedicels varying 

 in length but mostly shorter than the flowers, rarely longer, in loose or dense 

 paniculately cymose clusters, occasionally endogenously formed; calyx lobes 

 commonly reaching to about the middle of the corolla tube, mostly oval-ovate, 

 sometimes suborbicular or oblong, obtuse, overlapping at base, margins more 

 or less uneven; corolla lobes shorter than the tube, mostly oval-ovate, obtuse, 

 spreading; scales shorter than the corolla tube or reaching the filaments, oblong, 

 deeply fringed about the upper part, more shallowly so toward the base and on 

 the bridge; styles stoutish and sometimes somewhat subulate, mostly shorter than 

 or about equal to the ovary, occasionally longer; capsule mostly globose-conic to 

 obpyriform, surrounded by the withered corolla. 



The most common species of Cuscuta found throughout the cen. and n.e. states 

 and the W.I., w. to the Rocky Mts. (Coconino Co., Ariz.), commonly in low wet 

 areas where it grows on a great variety of hosts including species of Boehmeria, 

 Helianthus, Myrica, Solidago, Salix, Hypericum, Mimuhis and Lycopus; occasion- 

 ally reported as damaging ornamentals or other nonweedy hosts. 



Var. latiflora Engelm. The flowers are commonly smaller than in var. Gronovii, 

 the calyx lobes are more oblong-oval and less overlapping at the base and reach 

 the corolla sinuses, the corolla tube is broadly campanulate with the throat wider 

 than the tube which tapers toward the base and ordinarily is borne at the base 

 of the maturing and thus protruding naked capsule. 



Var. calyptrata Engelm. In this variety the corolla tube is commonly somewhat 

 longer than in var. Gronovii and with the lobes less than half as long as the tube, 

 when mature the capsule carries the withered corolla about the top; otherwise 

 similar to the var. Gronovii. 



14. Cuscuta cuspidata Engelm. Fig. 641. 



Flowers membranous in texture, about 3 mm. long from base to corolla sinuses, 

 subsessile or commonly pedicellate in loose paniculate clusters, the whole inflores- 

 cence more or less bracteate; calyx shorter than the corolla tube, of distinct or 

 very slightly united segments, subtended by one or more ovate-orbicular obtuse to 

 acutish sometimes cuspidate bracts, or these rarely lacking; calyx segments ovate- 

 orbicular, obtuse to acutish and cuspidate, the margins commonly thin and serru- 

 late, sometimes globular-thickened along the median line, broadly overlapping; 

 corolla lobes oval-oblong to subovate, shorter than the funnelform tube, commonly 

 more or less acute and somewhat cuspidate, occasional lobes serrate near apex, 

 sometimes obtuse, commonly with a line of pellucid glandlike cells along the 

 middle, spreading; scales shorter than the corolla tube, oblong, fringed with 



1368 



