NEW SPECIES OF MEXICAN PLANTS. 
BY J. M. GREENMAN. 
Cerastium lithophilum. A low herbaceous perennial: stems 
branched, the slender branches often becoming somewhat mat- 
ted: ultimate branches ascending, 0.5 to 1.5 dm. high, gland- 
ular-pubescent, mostly leafy: leaves crowded at the base of 
the ascending branches, more remote and about equalling the in- 
ternodes above, often appressed to the stem, linear-lanceolate, 10 
to 22 mm. long, 2 to 3 mm. broad, acute, entire, sessile and sub- 
connate at the base, glandular-pubescent on both surfaces: inflor- 
escence a terminal few-flowered cyme: flowers medium-sized for 
the genus: pedicels 4 mm. or less in length, and as well as the 
calyx densely glandular-pubescent: sepals oblong-lanceolate, 4.5 
to 5 mm. long, 1.5 to 2 mm. broad, obtusish, glandular-pubescent 
on the outer surface: petals white, oblanceolate-cuneate, 6 to 7 
mm. long, 2 mm. broad,deeply notched: stamens 10: ovary glab- 
rous; styles 5: capsule at maturity barely exceeding the calyx, 
1o-toothed at the apex.—MeExico. State of Mexico: in rocky 
soil, Mt. Ixtaccihuatl, March to July, 1903, C. 4. Purpus, No. 
231 (hb. Gr., hb. Brandg.). : 
Cerastium micropetalum. A low depressed annual (?), lan- 
ate-villous throughout: stems prostrate or ascending, 0.5 to 1 dm. 
in length, leafy: leaves opposite, sessile, linear-lanceolate, 8 to 1 5 
mm. long, 2 to°3 mm. broad, acute, entire, subconnate at the base, 
lanate-villous on both surfaces: inflorescence terminating the as- 
cending branches in few-flowered leafy cymes: flowers small: 
pedicels 5 mm. or less long, and as well as the stems above stipi- 
tate-glandular: sepals lance-oblong, about 3.5mm. long, 1.5 mm. 
broad, acutish, glandular-pubescent: petals oblong-cuneate, 2 to 
2.5 mm. long, notched for about one-third their length: stamens 
10: ovary glabrous; styles 5.—MrExico. Stateof Mexico: Mt. 
Ixtaccihuatl, 1903, C. A. Purpus, No. 473 (hb. Gr., hb. Brandg,). 
Cerastium Purpusi. A low depressed herbaceous perennial (?), 
forming rather dense tufts, 0.5 to 1.2 dm. in diameter: stems 
leafy, villous-pubescent: leaves spatulate to oblong, 8 to 20 mm. 
long, 3 to 8mm. broad, obtuse, entire, more or less white-villous- 
