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.
fertile aments only were collected by Dr. Bigelow, while Mr. Bentham describes only the male
flowers. There can be little doubt that our plant is the same as his. The fertile aments appear
after the leaves are nearly unfolded, and are produced at the extremity of short lateral branches.
They are cylindrical, and about two inches long. The capsules are smooth and distinctly pedicellate. Style short, but evident. Stigmas 2-lobed. Leaves 21 inches long and 6-8 lines wide,
distinctly serrulate. There' are in Dr. Bigelow's collection more advanced specimens of what
appears to be only S. lasiandra.. The leaves are fertile, aments are larger, but in other respects
there is little difference.
SALIX BIGELOVII (sp. nov.): foliis obovatis vel cuneato-oblongis obtusissimis integerrimis
subtus griseo-pubescentibus su'pra glabratis nitidulis; amentis (foemineis) brevi peduuculatis
cylindricis elongatis crassis, basi bracteosis; ovariis pedicellatis acutiusculis glabris; stylo
elongato; stigmatibus brevibus bilobis; squamis persistentibus villosis. Near San Francisco;
April 8, (with immature fruit.) Twigs rather stout, slightly pubescent, dark-brown, and
dull. Leaves 1-2 inches long, and to 4 of an inch broad, on short petioles of a firm but nt
coriaceouts texture. Female catkins nearly two inches long, and more than one-third of an inch
in diameter; the peaduncle 3-4 lines long; the small leafy bracts at base deciduous. Ovary
ovate, supported on a distinct pedicel. Scale about one-fourth the length of the ovary, darkbrown, but the color is concealed by the strong villous pubescence. We know not what else to
do with this well characterized willow but to describe it as a new species. It does not appear to
have been noticed by any writer on the plants of California and Oregon. The species to which
it seems nearest allied is S. planifolia of Hooker. The male flowers were not found. In the
collection of Dr. Bigelow was a Salix with female catkins only, which is perhaps the same
species as the one just described, but in a younger state. The leaves are silky-pubescent under
neath, and slightly pointed.
Two or three other Salices were collected in California, but we are unwilling to decide on
them without a more extensive study of all the allied species than we can give them at present.
URTICACEE.
URTICA URENS, Linn. So. 2. p. 284; Torr. Fl. N. York. 2.2 p. 222. Plains near San Gabriel;
March 23. Probably introduced from Europe.
HESPEROCNIDE, Nov. Gen.
FLORES MON01oICI. Masc. Calyx 4-partitum; foliolis equalibus concavis patentibus. Stamina
4. Ovaril rudimentum. Fern. Perigonium oblongo-ovatum, ventricosum; ore minuto bidentato
Ovarium liberum, ovatum, sessile; stigma sessile, pencillatum. Achenium lato, ovatum lenticulari-compressum, calyce membrauaceo immutato tectum. Herba annua Californica; pils urentibus; foliis oppositis ovatis petiolatis dentatis; florihus laxe glomeratis axillaribus, masculi et
fceminei in iisdem glomerulis.
HESPEROCNIDE TENELLA.-Shady rocks, Napa Valley, California; April 25. Stem slender, 38
inches high, simple, armed with scattered conspicuous stinging hairs. Leaves broadly ovate,
5-8 lines in diameter; obtuse, serrate-dentate, beset with a few stinging hairs on both sides,
and finely ciliate on the margin; petiole about one-third the length of the lamina. Axillary
glomerules 15-20-flowered, on short pedicels, mostly female, there being usually only one or
two males in a cluster. -Male. Calyx deeply 4-parted; the segments concave and somewhat
saccate at the summit. Stamens nearly twice as long as the calyx. In the centre of the flower
is the rudiment of an ovary. Female flowers articulated to a short stalk. Calyx clothed with
short uncinate hairs, acute, the orifice minute, bidentate. Ovary loosely but completely enclosed
in the calyx. Stigma terminal, nearly sessile, consisting of a tuft of short-jointed hairs.
Achenium enclosed in the thin membranaceous calyx, orbicular-ovate, acute, somewhat coriaceous, brownish. Embryo in thin albumen; cotyledons transversely reniform-orbicular; radicle
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