so ILLINOIS BIOLOGICAL MONOGRAPHS [140 



in 1889). Minnesota; Winona (ilolzinger in 1888). Nebraska; Exeter (Wibbe in 1889, in 

 ^ part), Lincoln (Hannah in 1916). Kansas; Riley Co. (Norton 358). 



Cuscuta pentagona Engelmann 



C. pentagona Engelmann, i\nier. Journ. Sci. & Arts, 43:340, pi. 6, figs. 22-24, 1842. Choisy 

 in DC, Prodromus, 9:461, 1845. ^ 



C. arvensis Beyrich in Hooker, FI. Bor. Am., 2:77, 1838; as synonym without description. 

 Engelmann in Gray, Manual of Botany, (2 ed.), p. 336, 1856; and in Trans. Acad. Sci. 

 St. Louis, 1:494, 1859. Hillman, Nev. Agr. Exp. Sta. Bull., No. 15, fig. 4, 1892. 

 Matthew, Bull. Torx. Bot. Club, 20, pi. 164, fig. 3, 1893. Piper, Wash. Agr. Exp. 

 Sta. Bull., No. 8, fig. 2, 1893. Britton & Brown, lUustr. Flora, 3:28, fig. 2958, 1898; 

 and 2 ed. 3:49, fig. 3444, 1913. 



hpithymum arvense (Beyrich) Nieuwland & Lunell, Amer. Mid. Nat., 4:511, 1916. 



Stems slender. Flowers 2-3 mm. long, glabrous to papillate or ver- 



rucose, pentamerous, on pedicels as short as or longer than the flowers in 



dense globular clusters; calyx lobes broad, obtuse, sometimes overlapping 



and angled; corolla broad, campanulate, lobes as long as or slightly longer 



than the tube, reflexed or spreading, with the tips acute and inflexed; 



scales longer than the tube, broad, ovate, deeply fringed, particularly the 



upper portion; stamens shorter than the lobes; anthers shorter than the 



filaments, slightly versatile, ovoid, elliptical; styles as long as or slightly 



longer than the globose ovary. Capsule globose, more or less depressed, 



the withered corolla remaining at the base; seeds 1-1.2 mm. long, light 



brown, usually four in a capsule, obovate or oval, compressed; hilum 



short, linear, oblique or transverse. 



Key to the varieties 



Calyx lobes overlapping, forming angles' at the sinuses; flowers relatively small typica. 



CaljTC lobes not at all or but slightly overlapping and not forming angles at the sinuses; 

 flowers usually larger. 



Flowers smooth, not verrucose or pubescent calycina. 



Flowers more or less verrucose or pubescent. 



Flowers more or less verrucose verrucosa. 



Flowers papillose-pubescent pubescens^ 



Cuscuta pentagona typica 



[Figures 32> a-e, 112 and 127] 



C. pentagona microcalyx Engelmann, Amer. Journ. Sci. & Arts, 45:76, 1845. 

 C. arvensis pentagona Engelmann, Trans. Acad. Sci. St. Louis, 1 :494, 1859. 

 ^' C. globtdaris Nuttall in Engelmann, Trans. Acad. Sci. St. Louis, 1:494, 1859; in synon. 



Smallest of the varieties. Calyx lobes smooth, roundish-triangular, 

 overlapping at the sinues forming angles. 



Type locality: Norfolk, Virginia. Range: From Massachusetts to 

 Florida and west to California. 



Specimens examined : United States : Fort Smith to the Rio Grande (Bigelow 1,9). 

 Massachusetts; Winchester (Bartlet 691, 696, Fernald & Weatherby 259, Rich in 1896), 

 Cambridge (Weatherby in 1911). Connecticut; Oxford (Harger in 1891), Simsbury (Bissell 

 in 1904). District of Columbia; Washington (Blanchard in 1890, Hillman in 1904, Hobn in 

 1893), Eckington (Boettcher 122), Takoma Park (Painter 745). New Jersey (Van Sickle in 



