ROBINSON. — SYNOPSIS OP THE GENUS MELAMPODIUM. 459 



M. cinereum, DC. However, it differs conspicuously in its more entire 

 erect or ascending thickish leaves, its much larger heads (nearly or quite 

 twice as broad) and its long thickish, firm, persistent, and veiny rays. 

 It is a much commoner and more widely distributed plant than M. cine- 

 reum, and may be conveniently regarded as a specific type. 



* * Lower surface of the leaves silky-villous, the pubescence more or less floccu- 



lent and tending to be deciduous. 



-t- Ligules shorter than or about equalling the fructiferous bracts : heads sessile 



or short-peduncled. 



9. M. SERiCEDM, Lag. Hoods tipped by a slender recurved append- 

 age.—" Elench. Hort. Madr. 1805," Gen. et Spec. Nov. 32 (1816) ; DC. 

 Prodr. v. 518; not HBK. — Mexico, Mendez ; Oaxaca, Pringle, no. 

 6728; Durango, Rose, no. 3476; Jalisco, Rose, nos. 2819, 3561; Espe- 

 ranza, Duges. 



Var. exappendiculatum. Hood destitute of a mucro or appendage, 

 sometimes itself obsolete. — In mountains near Morales, San Luis Potosi, 

 Schaffner, no. 271 in part; base of Iron Mountain, Durango, Dr. E. 

 Palmer, no. 926 (coll. of 1896) ; Guanajuato, Prof. A. Duges, Pringle, 

 no. 5309 ; Federal District, Pringle, no. 7978 (form approaching 31. 

 hispidum, HBK). 



■*- -I- Ligules conspicuous, usually much exceeding the fructiferous bracts : pedun- 

 cles long and slender. 



*+ Leaves (at least in part) pinnatifid ; segments rather broad. 



10. M. AMERiCANUM, L. Spec. ii. 921 (1753); Rel. Houst. 9, t. 21 ; 

 DC. Prodr. V. 518. — Vera Cruz, Mexico, Houston. "With this clearly 

 figured plant from Vera Cruz I have been unable to match any speci- 

 mens from Southeastern Mexico. However, the following specimens 

 from the western coast probably belong here : Manzanillo, Xantiis, and 

 Colima, Palmer, no. 136 (coll. of 1897), and no. 1172 (coll. of 1891). 



** ** Leaves, at least in part, deeply cleft, segments narrow, linear. 



= Outer bracts of the involucre pointless, surrounded by a thin yellow somewhat 



hyaline border. 



11. M. LlNEARiLOBUM, DC. Prodr. V. 518 (1836). M. sericeum, 

 Benth. in Oerst. Vidensk. Meddel. 1852, p. 86, not Lag. — A well-marked 

 species represented by the following specimens : Oaxaca, Nelson, nos. 2809, 

 2339 (pathological) ; Chiapas, Nelson, no. 2949 ; Guerrero, hills near 

 Iguala, Pringle, no. 9162 ; Nicaragua, Oersted; Sinaloa, Rose, no. 3183. 



= = Outer bracts of the involucre not membraneous-margined or colored, 

 herbaceous to the acuminate apex. 



12. M. longipes. M. sericeum, var. longipes, Gray, Proc. Am. Acad, 

 xxii. 423 (1887). — Erect, 4 to 5 dm. high, widely branched: upper and 



