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. 4, Pt. 3

BOTANY.
half long, ovate-elliptical, minutely pubescent on both sides, Pedluncles 4-6 inches long, (exclusive of the 10-14-flowered raceme.) Upper teeth of the calyx very short, and broadly triangular, with a minute point; all the teeth shorter than the tube. The stipules are larger than
in the eastern plant, but much smaller than the leaves. We have not seen the pods.
LATHYRUS VENOSUS, var. GRANDIFLORUS: caule nudo; foliolis (subdecum) minoribus supra
glabris; pedunculis folio subduplo longioribus; floribus maximis, dentibus calycis tubo subcequalibus. Cocomungo, March 17. The flowers are twice as large as in the ordinary form of
this species.
LATHYRUS VENOSUS, var. a. Torr. & Gray, 1. c. L. pubescens, Nutt. Mss. Hill-sides,
Benicia; April 24. This agrees with our Oregon specimens from Nuttall. It is between L.
venosus and vestitus, and seems almost to unite the two species.
LATHYRUS VENOSUS: var. OBOVATUS: caule nudo; foliolis sub-4-jugis plerumque obovatis obtusis
puberulis; racemo 3-4-floro; calcycis dentibus subequalibus. Near the Mammoth Grove and
at Duffield's Ranch, Sierra Nevada, May 15. A mountain form, with larger flowers than usual.
LATHYRUS OCHROLEUCUS, Hook. Fl. Bor.-.Am. 1, p. 159? Var. pedunculis 12-20-floris, folio
subequantibus. Hill-sides, Murphy's, May 12. Leaflets of a firm texture, and more approximated than in the eastern plant.
We are by no means satisfied with the results of our examination of the Lathyri in Dr.
Bigelow's collection. The species of this genus are extremely variable, especially those of
Oregon and California. It is possible that the true L. venosus does not grow on the northwest
coast; but we have not been able to discover characters sufficient for distinguishing from that
species any of the varieties enumerated above.
LATHYRUS POLYMORPHUS, Nutt. Gen. 2, p. 97; Gray, P1. Fendl., p. 30. Laguna Colorado, New
Mexico, September; and Santa Domingo, October; in low and wet places.
OROBUS LITTORALIS, Gray, in Stevens' Rep. ned. Astrophia littoralis, Nutt. in Torr. & Gray,
Fl. 1, p. 278. Specimens of this plant were given to Dr. Bigelow by Dr. Andrews. They
were probably collected on the coast, near San Francisco.
PHASEOLUS DIVERSIFOLIUS, Pers.; Torr. & Gray, Fl. 1, p. 279. Sand banks of the Canadian
River, near the Shawnee villages, etc. August.
PHASEOLUS PAUCIFLORUS, Benth.; Gray, Pl. Wright. 1, p. 44. With the preceding.
AMPHIcARPrA MONOICA, Torr. & Gray, Fl. l, p. 292. Ravines of Pecan creek; August.
PSORALEA PHYSODES, Dougl. in Hook. Fl. Bor.-Amer. 1, p. 304; Torr. & Gray, Fl. 1.. 304
and 689. Near Mark West's Creek, California. April 30. The stem is wholly free from glands.
PSORALEA CUSPIDATA, Pursh, F1. 2, p. 741. Rocky hills of the upper Canadian; September.
In fruit.
PSORALEA DIGITATA, Nutt. in Torr. & Gray, Fl. 1. p. 301. Sand-banks of the Canadian,
near the Shawnee villages; August. In fruit.
PSORALEA LINEARIFOLMA, Torr. & Gray, 1. c. Gypsum hills, Comanche plains; September.
PSORALEA MICRANTHA (sp. nov.): cinereo-puberula, minute glanduloso-punctata; caulibus e radice
seu rhizomate longissimo repente assurgentibus paniculato-ramosissimis; stipulis subulatis
minimis; foliis palmatim trifoliolatis; foliolis lineari-filiformibus incisve anguste linearibus
mucronato-acutis; pedunculis folio paullo brevioribus; spica brevi densifiora; bracteis minimis
caducis; calycis dentibus brevibus obtusissimis; fructu glabro.-Sand hills, near the last camp
on the upper Canadian; September. Plant a foot high, from a horizontal root or slender root stock of several feet in length. Branches slender, leafy. Leaflets an inch or less in length,
canaliculate and nearly filiform, or the lowest filat and about a line wide, punctate with fine
brown dots. Peduncles half an inch long, about the length of the subtending petioles, bearing
a short and oval or oblong spike of 10-20 small flowers, which are usually closely approximate
or crowded. Calyx short, scarcely a line long, rather longer than the pedicel, campanulate,
dotted with coarse brown glands; the short teeth broad and very obtuse, equal. Corolla barely
a line and a half long beyond the calyx, narrow, white, except the tip of the keel, which is blue.
77