[156] Humboldt's Personal Narrative, vol. i. p. 362. Philadelphia Edit.—JAMES. Another highly interesting plant, which occurs in the most barren and desolate parts of the plain, is a cucurbitaceous vine resembling some of our common squashes, bearing a small pepo, which is round and smooth, and as large as an orange. It is perennial, having a somewhat lignous root four or five inches in diameter, and descending often more than four feet into the earth. We were so fortunate as to meet with it in flower, and also with ripened fruit. It has the acutely margined seed of the genus cucumis, but in other respects is closely allied to cucurbita.[157] In addition to these, we collected the zigadenus elegans, Ph., asclepias tuberosa, and some others. [157] _Cucumis perennis_, S.—Calyx, seated upon the germ, rugose, coloured campanulate, exterior divisions subulate. Masc. Three filaments, short, closely covering the central disc. Fœm. Style short, stigmas three bipartite. Fruit. Pome large, orbicular, smooth, about four celled seeds, ovate, gibbous, margin acute; dissepiments torn, spongy; seeds in a double order; leaves alternate, triangularly cordate, margin undulate, tendrils axillary trichotomous; stems numerous, procumbent, grooved; flowers nearly as large as those of Cucurbita _pepo_; fruit round, smooth, and green, nearly sessile, resembling a small unripe water-melon. The leaves are rough, of a glaucous green colour, bitter and nauseous to the taste, and the whole plant emits a fœtid odour. Root fusiform, very large, six feet in length, and often four inches in diameter, descending perpendicularly into the earth. It inhabits the arid and sandy wastes, along the base of the Rocky Mountains, from the confluence of the Arkansa, and Boiling Spring Fork, to the sources of Red River. By means of its long and somewhat succulent root it is peculiarly adapted to the soil it occupies, and is found to thrive with considerable vigour in wastes whose thirsty and burning soils bid defiance to almost every other vegetable. It flowers in July, and continues flowering and perfecting fruit during the summer. Some plants of this interesting species are growing in the garden of the University of Philadelphia, from seeds brought by Major Long, but they have not yet flowered. The leaves are thick and robust, from six to eight inches long, and four or five in width, on foot-stalks equalling the leaves in length; they are crowded along the stems, and usually stand erect. It does not appear that any insect or animal preys upon the leaves or other parts of this plant. It forms, by its deep green, a striking contrast to the general aspect of the regions it inhabits, which are exceedingly naked and barren.