[92] In these villages, where the grass is fed close, and where much fresh earth is brought up and exposed to the air, is the peculiar habitat of a species of Solanum approaching the _S. triflorum_ of Nuttall, which, he says, occurs as a weed "about the gardens of the Mandans and Minatarees of the Missouri, and in no other situations." It appears to differ from the S. triflorum in being a little hirsute, with flat, runcinate, pinnatifid leaves, and the peduncles alternating with the leaves. The Solanum _heterandrum_ of Pursh, now referred to the new genus Androcera of Nuttall, is also very common, but is not confined, like the plant just mentioned, to the marmot villages. We collected also the Psoralea _cuspidata_, Ph. P. _esculenta_, N. P. _incana_, N. also a species of Hieracium—H. _runcinatum_. Plant hirsute, leaves all radical, elliptic-oblong, runcinate; scape few-flowered, somewhat compressed, and angular; glands on the hairs of the calix, very small and diaphanous; about one foot high; flower small. Hab. in depressed, grassy situations along the Platte. On arriving near the Platte we observed a species of prickly pear (_Cactus ferox. N._) to become very numerous. It resembles the common prickly pear of New Jersey, (_C. opuntia._) but is larger, and protected by a more formidable armature of thorns. Our Indian horses were so well acquainted with this plant, and its properties, that they used the utmost care to avoid stepping near it. The flowers are of a sulphur yellow, and when fully expanded are nearly as large as those of the garden pæony, and crowded together upon the summits of the terminal articulations of which the plant consists. These articulations, (or segments contained between the joints,) are oblong and flattened, being longer and thicker than a man's hand. A second species, the _C. mamillaris, N._ occurs on the dry sandy ridges between the Pawnee villages and the Platte. The beautiful cristaria _coccinea. Ph._ (malva _coccinea. N._) is very frequent in the low plains along the Platte. Its flowers {141} have nearly the aspect of those of the common wild rose, except that they are more deeply coloured. We arrived at the Platte, a little before sun-set, the distance from the Pawnees being, according to our computation, twenty-five miles. After entering the valley of the river, we travelled several miles across an unvaried plain, and at length passing down by a gradual descent of a few feet, we came upon a second level tract, extending to the river. The soil of the first of these portions is a bed of sand, intermixed with small water-worn pebbles and gravel; that of the latter is more fertile, and produces a luxuriant vegetation. Our guide informed us that the Platte, opposite the point where we entered its valley, contains an island which is more than one day's journey across, and about thirty miles in length.[93]