470 PROCEEDINGS OF THE AMERICAN ACADEMY. 
420, 1111, Pinos Altos Mts., Greene, no. 145; Arizona, ravines about 
Camp Grant, 23 April, 1867, Palmer, no. 106, banks south of Camp 
Apache, Rothrock, no. 271, Santa Catalina Mts., and at Ft. Bowie, 
Lemmon, uo. 127, also on Santa Catalina Mts., altitude 770 to 925 m., 
17 April, 1881, Pringle, Lemmon, no. 527; Texas, El Paso, Thurber, 
nos. 179, 1118, at Belknap, Sutton Hayes, no. 327 ; N. W. Mexico, 
Seemann (without number); Sonora, about Hermosillo, Crawford, 1888 ; 
S. W. Chihuahua, August to November, 1885, Palmer, no. 413; Coa- 
huila, Mts., 14.5 km. east of Saltillo, July, 1880, Palmer (without num- 
ber); region of San Luis Potosi, Schaffner, no. 842 a, and at Soledad, 40 
km. southwest of Monclova, September, 1880, Palmer, no. 4195 Morelos, 
at Tres Marias near Cuernavaca, altitude 2920 m., Pringle, no. 7233, 
A species on the one hand, through var. setulosum, approaching the 
South American R. ciliatum, Hemsl., and on the other, through the var. 
hispidulum, the Mexican R. polyplocum, Hemsl. 
Var. setulosum. Leaves setulose-ciliate: fruit granulose-hispid, 
otherwise like the species. — R. microphyllum, Hemsl. Biol. Cent.-Am. 
Bot. ii. 63, in part. — Zimapan, 7h. Coulter, no. 186; region of Sao 
Luis Potosi, Parry & Palmer, nos. 309, 310. 
Var. hispidulum. Habit of the species proper: stem and leaves 
covered with a scattered short hispidulous pubescence: fruit essentially 
glabrous, or somewhat granulose. — R. polyplocum, Hemsl. Biol. Cent- 
Am. Bot. ii. 63, in part. —Valley of San Luis Potosi, Schaffner, ® 
842; region of San Luis Potosi, altitude 1850 to 2460 m., Parry & 
Palmer, no. 308. Approaching the following species in the character 
the pubescence, but having a distinctly different habit. 
7. BR. polyplocum, Hemst. Herbaceous, closely hispidulous- 
pilose throughout : stems much branched forming dense mats 5 branches 
very slender, obtusely tetragonal as in the preceding species = leaves 
acute or obtusish, not distinctly cuspidate-tipped : flowers solitary, sessile 
in the small involucral bracts: fruit sessile or nearly so, small, white- 
granulose or glabrous. — Biol. Cent.-Am. Bot. ii. 63.— Southern Mexic?: 
Mirador, Liebmann, no. 244, and (according to Hemsley) no. 243 ; also 
Linden, no. 516. : 
R. Ascunxsonwit, Hemel.’ Biol. Cont-Am. Bot. ii.. 62, is Gon 
Aschenbornii, Schauer, treated above. 
of 
