Herbs with perfect regular nearly symmetrical flowers; sepals 5, persistent; petals 5 and alternate with the sepals; stamens 5 opposite the sepals. [Sidenote: =Linum Lewisii= Pursh. _Lewis’s Wild Flax._] Perennial from a woody root, 1—2 feet high, densely tufted, smooth, glaucous. Leaves crowded, oblong or linear, ¼—1½ inches long, acute or acutish, 3—5 nerved. Flowers bright blue, 1—1½ inches broad; petals 5, soon falling; sepals 5, oval, mainly obtuse, ⅓ or ¼ the length of the petals; stigmas shorter than the styles; stamens 5, longer than the styles. In open, dry, stony ground and slopes throughout the Rockies; flowering in June and July. [Illustration: Empetrum nigrum L. (Nat.) Black Crowberry.] [Illustration: Linum Lewisii Pursh. (¼ Nat.) Wild Blue-Flax.] EMPETRACEÆ _Crowberry Family_ Low evergreen shrubs with narrow nearly sessile leaves jointed to short pulvini, channelled on the lower side by the revolute margins and small monœcious, diœcious or rarely polygamous flowers; sepals, petals, and stamens each 3, fruit a black, berry-like drupe. [Sidenote: =Empetrum nigrum= L. _Black Crowberry._] Smooth or the young shoots hairy, usually much branched, the branches diffusely spreading, 2—10 inches long. Leaves crowded, dark green, linear-oblong, thick and obtuse, about ¼ of an inch long with strongly revolute, roughish margins. Flowers very small, purplish; stamens exserted; berry nearly ¼ of an inch in diameter, black. Frequent throughout the Rockies in damp woods, especially those of the “Jack Pine” where it frequently forms a considerable part of the forest floor, in dense, close mats. CELASTRACEÆ _Staff-Tree Family_ Shrubs with simple evergreen leaves, and regular perfect flowers, sepals, petals, and stamens each 4 in our species. [Sidenote: =Pachystima myrsinites= (Pursh) Raf. _Mountain Lover._] Low evergreen shrub, densely branched or nearly simple, 1—3 feet high. Leaves opposite, smooth, ovate to oblong or lanceolate, cuneate at the base, the upper half serrate or serrulate ½—1 inch long on very short petioles. Flowers small in axillary cymes; petals 4, stamens 4, inserted at the edge of the broad disc. In gravelly and stony situations extending from the Valley of the Columbia River at Beavermouth, westward throughout the Selkirks, the minute blossoms appearing in the latter part of May; a pretty but very variable shrub in habit and leaf form. [Illustration: Pachystima myrsinites (Pursh) Raf. (½ Nat.) Mountain Lover.] [Illustration: Viola adunca longipes (Nutt.) Rydb. (⅔ Nat.) Dog Violet.] ACERACEÆ _Maple Family_ Trees or shrubs with watery often saccharine sap, opposite, simple and palmately lobed leaves and axillary or terminal, cymose or racemose, regular, polygamous or diœcious flowers; fruit of 2 long-winged samaras, joined at the base. [Sidenote: =Acer glabrum= Torr. _Smooth Maple._]