ROBINSON & GREENMAN: CONTRIB. GRAY HERBARIUM. 99 
scabrous : leaves alternate or scattered (the middle ones occasion- 
ally verticillate), 6 to 13 em. long, 1.2 to 3.4 cm. broad, promi- 
nently 3-nerved : heads on long stout ascending alternate peduncles, 
subglobose, 2 to 2.5 cm. in diameter.— Biol. Cent.-Amer. Bot., 
, 163. G. rudis, Gray, Proc.. Amer. acad., 22, 424. G. rudis, 
var, minor, Rob. and Greenm., ibid, 29, 387 (small form). — The 
type (in herb. Kew), collected in Mexico, without locality, by Park- 
inson, has brownish-purple flowers. This form is represented also 
by Palmer’s no. 531 from the Rio Blanco, Jalisco, Pringle’s no. 
4584 from rocky hills near Tequila (small form), and Rose’s no. 
3031, coll. between Bolafios and Guadalajara, and no. 3700 coll. 
at Bolaiios. This typical form is connected by variegated transi- 
tions with a forma flaviflora in which both disk- and ray-flowers 
are golden yellow. The latter form is represented by Pringle’s 
no, 2460, from hillsides near Guadalajara, Palmer’s no. 533 from 
the Rio Blanco, and Rose’s no, 2827, coll. between Colotlan and 
Bolaiios, Jalisco. No morphological differences between the indi- 
viduals with brown-purple flowers and those with yellow flowers 
have been detected. 
** * * * Heads large (1.6 to 1.8 cm. broad excl. of rays), terminal, solitary ; 
involucral bracts narrow, lance-linear, attenuate: rays long: leaves lance- 
27. G. serrata. Perennial: stems several, 5 dm. high, un- 
branched, striate, terete, puberulent, leafy, 1 (-2)- headed: leaves 
lance-oblong, opposite or alternate, attenuate, conspicuously ser- 
rate, shortly petiolate, scabrous-puberulent above, scarcely paler, 
pubescent, and reticulate veiny beneath, 6 to 12 cm. long, 1 to 2 
em. broad: involucral bracts herbaceous, lance-linear, attenuate, 
appressed-canescent-pubescent especially on the mid-nerve, 1 to 1.2 
cm. long: rays deep yellow, oblong, 1.5 to 2.5 em. long, 5 to 8 
mm. broad: disk-corollas yellow, essentially glabrous, 6 mm. long: 
immature achenes 4 mm. long, glabrous, destitute of pappus. -- 
Collected in 8S. W. Chihuahua on Mt. Mohinora, 1 September, 1898, 
W. Nelson, no. 4891. Types in herb. U.S. nat. museum and 
herb. Gray. 
* * * * * * Heads of medium size, most of them sessile or shortly singer 
in few many-headed leafy corymbs: involucral bracts ovate, obtuse, 
spicuously squarrose : leaves ovate, sessile. 
28. G. squarrosa, Benth. and Hook.f. Erect perennial herb, 
oe 
simple below, comers and copiously pubescent: leaves serrate 
