74 Contributions from the Gray Herbarium 
(B. M., G., K., Mo., U.S.) & 300 (B. M., G., K., Mo., U.S.); San 
Luis Potosi: 1878, Parry & Palmer 452 (B. M., G., K., U. 8.); 
sandy places near San Luis Potosi, Sept. 1876, Schaffner 260 (G.), 
261 in part (G.); shady swampy places, 1880, Schaffner 386 (G., 
K.); without definite locality, 1891, L. F. Ward (U. 8.). —T. 2. 
Fia. 6 
The following are more or less intermediate between var. genuina 
and var. latisguama. Coanutua: Sierra de la Paila, Oct. 1910, 
Purpus 4693 (B. M., Mo.); Sierra de Parras, July 1910, Purpus 
4566 (B. M., G., Mo., U.S.); 1. ¢., Oct. 1910, Purpus 4641 (B. M., 
G., Mo., U. S.); San Luis Porost: sandy places near San Luis 
Potosi, Sept. 1876, Schaffner 261 in part (G.). 
Var. LaTIsquaMa Greenm. Phayllaries oblong, strongly grad- 
uated, mucronate at the obtuse apex, with more or less strongly 
indurated base and much shorter subherbaceous tip. — Greenm.! 
Proc. Am. Acad. xxxix. 103 (1903). — MEXICO: Durango: 
near City of Durango, Sept. 1896, Palmer 667 (COTYPE COLL.: B. 
M., G., K., Mo., U. S.), 747 (corypr couu.: B. M., G., K., Mo., 
U. S.); Zacarecas: near Concepcion del Oro, 22 Nov. 1902, 
Palmer 379 (G., Mo., U.8.). — In involucral characters this variety 
makes a strong approach to the series Maculatae. — T. 2. Fra. 7. 
2 - RHOMBIFOLIA (Rob. & Greenm.) Blake. Herbaceous 
perennial, several-stemmed from a thick woody root, decumbent, 
1-1.3 m. long; stems hispid and granulose, rather few-leaved, 
paniculately branched above, the internodes very long. Leaves 
opposite except in inflorescence, rhombic-ovate, acute, rather 
abruptly narrowed below the middle to a broadly margined sub- 
amplexicaul base (broadly margined petiole) 1-1.4 cm. wide, the 
lower shortly naked-petioled, very scabrous above, rough with a 
tuberculate hispidity beneath, serrate above the middle or the 
uppermost entire, 3-nerved, 5.5-9 cm. long, 1.8-4.2 em. wide; 
those of inflorescence lance-oblong, acute, entire, 1.8-3.5 cm. long. 
Heads numerous in a long loose paniculate inflorescence, about 
2.3 em. wide; ultimate pedicels 2-12 em. long; disk 11 mm. high, 
911 mm. thick. Involucre 3-seriate, 10.5-12.5 mm. high, the 
canescently hispid-pilose and granular, subherbaceous, appressed. 
Rays 8, 9mm. long, 3mm. wide; disk-corollas yellow, purpurascent 
