184 New Species of Mexican Plants. [ZOE 
pubescent on both surfaces, the lowermost narrowed into a sub- 
petiolate base, the upper sessile: infloresence terminal, cymose, 
few-flowered; pedicels 4 mm. or less in length: flowers medium- 
sized for the genus, about 1 cm. in diameter: sepals oblong, ob- 
tuse, 5 mm. long, 2 to 2.5 mm. broad, villous-pubescent: petals 
oblong-cuneate, exceeding the calyx, 6 to 7 mm. long, notched 
at the apex: ovary glabrous; styles 5: capsule at maturity slightly 
exceeding the calyx, about 6 mm. long: seeds subrotund, about 
I mm. in diameter, reddish, minutely tuberculate.—MEXxIco. 
State of Mexico: Mt. Ixtaccihuatl, 1903, C. A. Purpus, No. 472 
(hb. Gr., hb. Brandg.). 
Arenaria oresbia. An herbaceous perennial: stems prostrate 
or ascending, bifarious-pubescent; internodes 1 to 30 mm. in 
length: leaves opposite, close and more or less imbricated, or re- 
mote and much exceeded by the internodes, lanceolate to ovate- 
lanceolate, 4 to 10 mm. long, t to 4mm. broad, acute, entire, more 
or less ciliate, subconnate at the base, thickish, glabrous on both 
surfaces, often pubescent on the prominent or somewhat keeled 
midrib beneath: flowers terminal or lateral, few: pedicels mostly 
short (less than 5 mm. long), occasionally 2 cm. in length, pubes- 
cent: calyx slightly urceolate; sepals lance-ovate and acute to 
lance-oblong and rather abruptly narrowed at the mucronate- 
acute apex, 4 to 6 mm. long, rather conspicuously keeled, scarious- 
margined, glabrous: petals exceeding the calyx, oblong-spatulate 
to slightly obovoid, 5 to 8 mm. long, sometimes slightly undulate- 
margined, white: stamens 10: ovary glabrous; styles 3: capsule 
4 to 5 mm. long, separating from the top at maturity into 6 valves, 
—MExIco. State of Mexico: meadows on Mt. Ixtaccihuatl, alti- 
tude 3350 to 3655 m., March to July, 1903, C. A. Purpus, No. 288 
(hb. Gr., hb, Brandg.). State of Jalisco: Nevado de Colima, 
altitude 3655 m., 16 May, 1903, C. G. Pringle, No, 5514 (hb. Gr.). 
The leaves in Mr. Pringle’s specimens are less ciliate than those 
collected by Mr. Purpus, but in other regards the correspondence 
is so close that the writer has no doubt the 
sentatives of one and the same species. 4. oresbia suggests in 
some ways the 4. scopulorum, HBK., but the leaves of the 
former are of distinctly different outline, the calyx-lobes are 
two plants are repre- 
