ROBINSON. — SYNOPSIS OF THE GENUS MELAMPODIUM. 457 



3. M. longicornu, Gray, Mem. Am. Acad. v. 321 (PI. Thurb.), 

 1854, where by misprint longicorne. — S. Arizona, near Ft. Huaclmca, 

 Lemmon, no. 2777 ; Sonora, Santa Cruz, Thurber, no. 937 (type) ; Chi- 

 huahua, near the city, Pringle, no. 10 ; San Luis Potosi, Parry & Palmer, 

 no. 443J. 



■*-*■ ++ Ligules longer, exceeding the involucral bracts, conspicuous : peduncles 



mostly long. 



= Soft-stemmed, strictly herbaceous and annual. 



a. Pubescence sliort, scanty : leaves oblong to linear, entire : appendage of the 



hood long: involucre gamophyllous about to the middle. 



4. M. appendiculatum. Slender, erect, sparingly pubescent an- 

 nual, 3 to 4 or more dm. high, branched almost from the base : leaves 

 thin, oblong to linear, attenuate at the apex, scarcely narrowed to the 

 sessile subauriculate base : obsoletely serrate to quite entire, the larger 

 ones (near the middle of the stem) 5 cm. long, 1 cm. broad : pedun- 

 cles 2 to 7 cm. long, erect, slender : involucre saucer-shaped or shal- 

 lowly cup-shaped, gamophyllous, the limb shallowly 5-lobed; the lobes 

 rounded or barely and very obtusely pointed, their margins scarious : 

 pubescence of the peduncles and involucres short and sparing : rays 

 8 to 10, oblong, yellow, 6 mm. in length, 2-3-toothed at the apex ; fruit 

 tuberculate, the conspicuous appendage a linear coiled awn from an 

 ovate-lanceolate somewhat 2-toothed base : pales scarious. — South- 

 western Chihuahua, Dr. Edward Palmer, no. 245 (collection of 1885). 

 Type in herb. Gray. This species has the outer involucre of M. 

 cupulatum, Gray, and the fruit of M. longicornu, Gray, yet it is 

 clearty distinct from both, differing from the former not only in its long 

 peduncles and 'well-developed ligules, but in stature and in the size of the 

 leaves, and from the latter in the presence of a hood and appendage 

 (both totally lacking in M. cupulatum) and in the subauriculate base of 

 the leaves. 



Var. leiocarpum. Similar in all points but the fruit smooth, striate, 

 glandular-punctate, not at all tuberculate. — Collected by Dr. Edward 

 Palmer at Alamos, 16-30 September, 1890, no. 726. Type in herb. 

 Gray. 



Var. sonorense. Involucre deeper, subcampanulate : fruit slightly 

 roughened : otherwise like the type. — Collected by C. V. Ilarttnan at 

 Cochuto, Sonora, 2 October, 1890, no. 71. Type in herb. Gray. 



b. Pubescence short and stiff: leaves lanceolate, undulate: fruit hooded, but 



the appendage shorter or sometimes obsolete. 



5. M. arenicola. Decumbent or suberect, branching from near the 

 base; stems dark purple, covered with stiff white somewhat refluxed 



