98 



CONVOLVULACEiE. 



Calystegia. 



2. Calystegia spitham^ea, Pursh. Upright Bindweed. 



Erect, oblique or sometimes nearly procumbent, hoary-pubescent ; leaves obovate-oblong, 

 obtuse or acute ; peduncles usually longer than the leaves ; bracts ovate, acute ; calyx two- 

 thirds the length of the bracts , its sepals lanceolate. — Pursh, fl. I. p. 143 ; Hook, exot.fl. 1. 

 t. 97, and fl. Bor.-Am. 2. p. 77. C. tornentosa, Pursh, I. c. Convolvulus spithamaeus, 

 Linn. sp. I. p. 158 ; Ell. sk. I. p. 251 ; Torr. fl. I. p. 225. C. stans, Michx.fl. I. p. 136 ; 

 Bigel. fl. Bost. p. 79. 



Perennial. Stem 8 inches - 2 feet long, sparingly branched, never twining. Leaves 

 varying from acuminate to obtuse. Peduncles one or two from the lower part of the stem, 

 not often shorter than the leaves. Bracts completely covering the calyx. Corolla white, 

 nearly two inches long. Styles sometimes cleft one-third of the way down : stigmas oblong. 



Dry woods and copses ; not common. June. A somewhat variable species, especially as 

 to height ; but there can be little doubt that C. stans of Michaux is one of its forms. 



Suborder CUSCUTINEvE. Link The Dodder Tribe. 



Capsule opening all round, or bursting irregularly. Embryo spirally coiled, 

 around mucilaginous albumen, without cotyledons. — Parasitical twining plants, 

 destitute of verdure, but furnished with little scales instead of leaves, usually 

 of a reddish or orange color. Flowers in small cymules, which are often 

 densely aggregated. All the species first spring from the ground, but soon 

 attach themselves to other plants, from whence they draw their nourishment 

 by means of numerous papillose roots, and thus become truly parasitic. 



3. CUSCUTA. Linn. ; Endl. gen. 3816 ; Choisy in mem. soc. phys. et aVhist. nat. Genev. 

 9. (1841 - 2) ; Englemann in Sill, jour n. 43. (Oct. 1842), p. 335.* DODDER. 



[ Etymology uncertain.] 



Calyx 4 - 5-cleft. Corolla urceolate-campanulate, 4 - 5-cleft. Filaments often with scales 

 at the base. Styles 2, distinct or rarely united : stigmas filiform or (as in all the indigenous 

 North American species) capitate. Capsule imperfectly 2-celled, 4-seeded ; one or more 

 of the seeds often abortive. — Habit that of the suborder. 



* See Dr. Englemann's elaborate and accurate monograph of the North American Cuscutineffi, in the work here quoted. 

 The author had been anticipated in several of his species by Choisy, whose memoir appeared a short time earlier, so that 

 some changes in the nomenclature were required. These were made in Dr. Englemann's additional paper, in Sill, jour, 

 vol 45, July 1843. 



