Cuscuta. 



CONVOLVULACE^. 219 



E. Di'scoLOR, Bentli. (E. holosericeus, var. obtusatus, Choisy, 1. c), of Mexico, with shorter and 

 procumbent or prostrate stems, ovate or oblong obtuse leaves, more villous pubescence and 

 larger corolla, seems to be a good species, as Meissner also supposes ; but is not found on our 

 immediate borders. Dr. Torrey's plant so referred is mainly E. Arizonicus. 



^^ H_- Both sides of the leaves, steins, and calyx densely silky-villous. 

 E. argenteus, Pursh. Stems numerous from a lignescent base, rather stout and rigid, 

 erect or ascending, a span or so high, very leafy : dense pubescence sometimes silvery- 

 canescent, usually fulvous or ferruginous : leaves from spatulate and obtuse to linear- 

 lanceolate and acute (a quarter to half inch long) : pedicels very short : sepals lanceolate- 

 subulate : corolla purple or blue (not " yellow " as says Pursh), 3 to 6 lines in diameter. — 

 Fl. i. 187, not R. Br. ; Clioisy, 1. c. ; Torr. 1. c. E. pilosus, Nutt. Gen. i. 174 (as additional 

 name), & in Trans. Am. Phil. Soc. ser. 2, v. 195, not Lam. E. Nuttallianus, Rcera. & Sch. 

 Syst. vi. 198. — Sterile plains and prairies, Nebraska to Texas and west to Arizona. Pine 

 Key, Florida, Blochjett, in small and insufficient specimens. (Adjacent Mex.) 



7. CRESSA, L. (Greek name for a female Cretan.) — Genus apparently 

 of a single but very variable and widely diffused species- 



C. Cretica, L. Low canescent perennial, much branched from a lignescent base, erect or 

 diffuse, a span or two high, very leafy : leaves entire, from oblong-ovate to lanceolate, 

 sessile, 2 to 4 lines long : flowers subsessile or short-pedicelled in the upper axils, or the 

 upper crowded as if in a leafy-bracteate spike : corolla white, 2 or 3 lines long, sericeous- 

 pubescent outside. — Lam. 111. t. 183; Sibth. Fl. Graca, t. 256. (S. Eu., Air., S. Asia, 

 Australia, &c.) 



Var. Truxillensis, Choisy. A more silky-villous and stouter form, mostly larger- 

 leaved : capsule larger, 2 or 3 lines long. —Choisy in DC. 1. c. 440; Torr. 1. c. C. Truxil- 

 lensis, HBK. isTov. Gen. & Spec. iii. 119. — On or near the sea-shore or in saline soil, Cali- 

 fornia, and from Arizona to S. Texas. (Hawaian Islands, S. Amer., &c.) 



8. CtJSCUTA, Tourn.* Dodder. (Name said to be of Arabic derivation.) 

 — Flowers 5-merous, rarely 4-merous, white or whitish, small, in loose or dense 

 cymose clusters, usually produced late in the season. Calyx cleft or parted. 

 Corolla from campanulate or somewhat urceolate to short-tubular, with the 

 mostly spreading lobes between convolute and imbricated in the bud, not 

 plicate, marcescent-persistent either at base or summit of the capsule. Sta- 

 mens inserted ' in the throat of the corolla above as many scale-like lacerate 

 appendages (scales) ; these rarely absent. Ovary globular, 2-celled, 4-ovuled. 

 Styles distinct, or rarely united, persistent : stigmas globose, or in Old-World 

 species filiform. Capsule I-4-seeded, circumscissile or transversely bursting, 

 or indehiscent. Seeds large, globular, or angular by mutual pressure. Embryo 

 filiform, spirally coiled in the firm-fleshy albumen, wholly destitute of cotyledons, 

 but the apex, or plumule, often bearing a few alternate scales, germinating in the 

 soil, but not rooting in it, developing into filiform and branching annual stems 

 of a yellowish or reddish hue, which twine dextrorsely upon herbs or shrubs, 

 and become parasitic by rtleans of suckers which penetrate the bark in contact, 

 the base soon dying away. Small .scales of the same color as the stem take 

 the place of leaves and bracts. — Choisy in Mem. Genev. 1841 (cited " Cusc") & 

 DC. Prodr. ix. 452 (1845) ; Engelm. in Am. Jour. Sci. xliii. (1842), 333, Gray, 

 Man., & Trans. St. Louis Acad. i. 453 (1859), here cited as " Cusc." 



§ 1. GrXmmica, Engelm. I.e. Styles (more or less unequal) terminated by 

 peltate-capitate stigmas. — Grommica, Loureiro. (Comprises the greater part 

 of the species of this large genus, almost all of them American and Polynesian.) 



* Contributed by Dr. George Engelmann. 



