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.
very unequal, lanceolate, sharply carinate, each terminating in a bristle as long as itself.
Paleve somewhat coriaceous, linear-lanceolate, almost terete, long as the upper glume; the
inferior acute, rough on the keel; superior pubescent on the back, with two approximate nerves,
which are produced into teeth at the summit. Stamens 3; anthers linear. Styles long; stigmas plumose on the inside. Caryopsis linear-fusiform.
MONROA. Nov. Gen.
Spacula 2-6-flor; flores sessiles distichi hermaphroditi v. terminali tabescente. Glumr 2,
suboppositee mucronatee, flores multobreviores. Paleee 2 herbaecoe rigidre, inferior apice
mucronata vel brevissime aristata, ecarinata, Equilatera, lateribus in spicule superiores versus
basim baribatis, in spicula infima plerumpue glabris. Caryopsis glaberrima, palea superiori
obtecta. Gramen annuum, repens, ramosissimum, ramis fasciculatis. Spica capitulformi
seepius foliorum terminalium subspatheeformibus suffulte. Spicule 3, 2-6-flor.
MONROA SQUARROSA. Crypsis squarrosa, Nutt. Gen. 1, p. 49. Hills and ravines, Anton Chico,
New Mexico; September. "On the arid plains of the Upper Missouri, near the Grand
Detour, it covers, almost exclusively, thousands of acres."-Nutt. This grass is very distinct
from Crypsis, and belongs, as we think, to the tribe H6rdeacee. In the notice of Dr. James'
plants, collected in Long's 1st expedition, (Ann. Lyc. Nat. Hist. N. York, 2, p. 254,) it was
intimated that it was probably a distinct genus. The culm is prostrate, much branched from
the base; the branches 3-8 inches long. Leaves 1-2 inches long, flat, 1-2 lines'wide, somewhat
pungent, scabrous on the margin; those near the summit of the fasciculate branches with broad
sheaths, embracing the small sessile heads, which thus appear involucrate. Spikelets
mostly 3, closely approximated, usually 3-4-flowered. Glumes sometimes almost unilateral,
linear-lanceolate, carinate. Paled 2-3 times longer than the glumes, lanceolate, acute; the
lower one often bifid or 2-toothed at the summit, with a cusp or very short rigid bristle between
the teeth 3-nerved; the lateral nerves nearly marginal. In the uppermost spikelet, and often
in the middle one, these nerves are bearded with long white hairs towards the base; but the
flowers of the lowest spikelet are usually quite naked. Superior palea bicarinate, rather obtuse.
Stamens 3; anthers linear. Styles long and slender; stigmas plumose. Achenium compressed,
very smooth and even, usually covered with the introflexed margin of the superior palea. We
dedicate this singular genus to Major Monro, of the East India Conmpany's service, who has made
the grasses an especial study.
TRITiCUM (AGROPYRUM) REPENS, Linn. Prairies, on the Canadian River; August. An awnless glabrous form, with narrow and somewhat involute leaves.
SETARIA GLAUCA, Beauv.; Kunth, Entum. p. 149. Banks of Little River, Indian Territory;
August.
SETARIA vIRIDIS, Beauv.; Kunth, 1. c. p. 151. Laguna Colorado, New Mexico; August.
PANICUM CRUS-GALLI, Linn. Oplismenus Crus-Galli, Kunth, 1. c. 1, p. 143 With the last;
also on the banks of the Pecos, New Mexico. All the specimens from the latter locality
belong to the awnless variety.
PANIcUM VIRGATUM, Linn.; Kunth 1. c. p. 100; Torr. Fl. N. Y. 2, p. 425. With the last.
PANICUM SANGUINALE, Linn.; Torr. 1. c. p. 423. Alluvial banks of the Canadian, and near
Galisteo, New Mexico; August-October.
PANICUM LATIFOLIUM, Linn.; Torr. 1. c. p. 425. With the last.
PANICUM OBTUSUM, H. B. K.? Torr. in Marcy's Rep. p. 299. Plains, Laguna Colorado, New
Mexico; September.
CENCRRUS TRIBULOIDES, Linn.; Torr.'F. New York, 2, p. 931. On the Canadian River, and
near Galisteo, New Mexico; October.
TRIPSACUM DACTYLOIDES, Linn.; AJIchx. Fl. 1, p. 60. Pecan creek, -Indian Territory. T.
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