458 PROCEEDINGS OF THE AMERICAN ACADEMY. 



hairs : leaves lanceolate from a narrowed auriculate base, undulate to 

 sparingly and irregularly scabrous-pubescent upon both surfaces, 3 to 

 5 cm. long, 8 to 1 1 mm. broad: peduncles slender, pubescent, 3 to 7 cm. 

 long; heads often nodding, 1.2 cm. in diameter (including narrow yellow 

 entire or bidentate ligules); involucre shallow, saucer-shaped, the 5 divi- 

 sions united nearly to the middle, broad, scarious and ciliate at the 

 margin : fruit finely striate, punctate and slightly tuberculate, bearing 

 a well-developed hood surmounted by a slender recurved hispidulous 

 appendage not flanked by lateral teeth at the base. — Collected by F. II. 

 Lamb in sandy soil on Isla Piedra, Mazatlan, Sinaloa, 31 December, 

 1 89 I. do. 861a. Mr. Lamb's no. 380 also from Mazatlau differs in hav- 

 ing no tubercles upon the fruit and in the obsolescent appendage, yet it 

 is probably of the same species. Type in herb. Gray. 



Pubescence copious, soft, long, villous: leaves ovate-lanceolate to ovate: ap- 

 pendage of the hood short : involucre gamophyllous only near the hase. 



6. M. LONGIPILUM, Robinson. Involucre externally villous, its 

 divisions acutish. — Proc. Am. Acad, xxvii. 173 (1892). — San Luis 



~i. Pringle, nos. 3G39, 4537. 



= = Stems tending toward lignescence : roots at least in part perennial : species 

 of northern Mexico and southern United States. 



Heads rather small, (including the rays) about 1 to 1.2 cm. in diameter: 

 leaves conspicuously sinuate or pinnatifid: rays thin, short. 



7. M. cinkki im, DC. 1. c. (1836). Hood muticous. — Laredo, Texas, 

 Berhtndicr, who appears to have confused this with the variety ramosissi- 

 ntinu. so that his numbers cannot be depended upon. 



Yar. BAMOSISSJMTJM, Gray. Hood mucronate. — Syn. Fl. i. pt. 2, 

 239 (1884), in part. M. ramosissimum, DC. Prodr. v. 518 (1836).— 

 Near Laredo, Berlandier, S. W. Texas and adjacent Coahuila, Palmer, 

 no.. 556, 557, 558 (coll. of 1880). 



Var. ARGorriYLLUM, Gray. Hood muticous: leaves small, tomentose 

 upon both Mirfaces, canescent above, snowy white beneath. — Gray in 

 Wats. Proc. Am. Acad, xviii. 104 (1883 without description). — 

 Coahuila and Nuevo Leon, Palmer, no. 2068 (coll. of 1880). 



>. M. in. wnir.M, Torr. & Gray, Fl. ii. 271 (1842). — The com- 

 mon, 'st form of our southwestern States. Kansas, Hamilton County, 

 Hitchcock, no. 250; W. Texas, Lindheimer, no. 636, Reverchtm, no. 

 1880*, Thurher, no. 128, Heller, no. 1632, Pope, Bigelow, Wislizentu ; 

 New Mexico, Thurber, no. 1105, Wooton, no. 117; Arizona, Rothrock, 

 do. 827, Palmer, no. 608, Pringhy coll. of 1884; Chihuahua. Pringle. 

 This plant has of late been generally regarded as a mere form of 



