Reports of explorations and surveys, to ascertain the most practicable and economical route for a railroad from the Mississippi River to the Pacific Ocean: Vol. 5, Pt. 2

ARTICLE VII.
DESCRIPTIONS OF PLANTS COLLECTED ALONG TiHE ROUTE, BY W. P. BLAKE,
AND AT THE MOUTH OF THE GILA.
BY JOHN TORREY.
Mr. Blake, the geologist of the Expedition commanded by Captain Williamson, having
requested me to examine and report on the plants that he found in his explorations, as well as
those collected near Fort Yuma, by Major Thomas and Lieutenant Du Barry, of the United
States army, I have prepared the following list. The drawings for the illustrations were made
by Mr. E. Dwight Church, a young artist of this city, and the engraving was executed by Mr.
Prestele.
JOHN TORREY.
NEW YORK, May 1, 1857.
ARGEMONE MEXICANA, Linn. On the Colorado, and in other parts of California. An extremely
hispid white flowered variety, which seems to be the same as A. munita, Durand & Hug. Pt.
Herm.
NASTURTIUM OBTUSUM, Nittt. in Torr. & Gray, Fl. 1, p. 74. With the last, in wet places.
Flowers through the summer.
SISYMBRIUM DEFLEXUM, Harv.; Torr. in Bot. Whipp. Rep. Sandy places in the Colorado.
Varies greatly in size.
DITHYREA CALIFORNICA, Harv. in Hook. Lond. four. Bot. 4, p. 77. t. 5; Torr. in Bot. Wid).
Rep. California desert; March.
OLIGOMERIS GLAUCESCENS, Camb.; Gray, PI. Wright{, 2, p. 16. Dry places between the
Colorado and the sea coast; April, Julie.
SESUVIUM PORTULACASTRUM, Linn.; DC. Prodr. 3, p. 453; Var floribus subsessilibus, Gray, PI.
Wright, 1, p. 13. Flowers on short pedicels. Stamens about 50. Sandy banks of the Colorado.
FAGONIA CALIFORNICA, Benth. Bot. Sulph. p. 10. Near Fort Yuma. This species is, as
Bentham remarks, closely related to F. Chilensis and F. Cretica; but we think it more closely
approaches the former than the latter. (Tab. I.)
LARREA MEXICANA, Moricand; Torr. in Emory's Report, p. 137, t. 0. This is the well known
Creasote-plant or Creasote bush. It grows from four to six feet high. It is very common in the
desert west of the Colorado, and in barren spots on the mountains near that river.
SPHERALCEA INCANA, Torr. in Gray, PI. Fendcl. p. 23; Gray, PI. Wright, p. 21. River aliti