Stems erect or ascending, simple or at length, sparingly branched, finely hairy throughout, 4—12 inches high. Leaves thin, oval, or oblong, ½—1 inch long, obtuse, spreading, the margins and nerves fringed with hairs. Flowers few in lateral and terminal clusters or sometimes solitary; ¼ of an inch or more broad, their parts in 4’s or 5’s; sepals oblong, obtuse or acute, half as long as the nearly entire white petals. In moist places growing among grass, throughout the Rockies; flowering in June. [Sidenote: =Arenaria capillaris nardifolia= (Ledeb.) Regel. _Rock Sandwort._] Smooth throughout except the tops of the stems and sepals, which are glandular; stems slender, 4—8 inches high, numerous from a tufted, leafy base. Leaves mostly in bundles ½—1½ inches long, smooth, very slender and curved, with a spiny tip, those of the stem few and much reduced. Flowers white, ½ an inch broad in a loose branching head. A rather striking plant on grassy slopes throughout the region; flowering in June. [Sidenote: =Arenaria verna equicaulis= A. Nelson. _Vernal Sandwort._] Very slender, much branched and finely, sticky-hairy throughout; stems thread-like, numerous, nearly of a uniform length in the same plant, 2—3 inches long. Leaves crowded at the base, few and much reduced above, linear, awl-shaped, thick, semi-cylindric, nearly smooth. Flowers small, little more than ⅛ of an inch across; sepals ovate-oblong, acute, strongly 3-nerved; petals white, acute, not exceeding the sepals. A small tufted plant with wiry stems and minute white star-like flowers, in moist or dry, sandy places throughout the region from the low valleys to the alpine summits; flowering in May and June. [Sidenote: =Arenaria sajanensis= Willd. _Alpine Sandwort._] Closely tufted, stems densely glandular-hairy, decumbent, very leafy below, ½—2½ inches long with 2 or 3 pairs of short, rather distant leaves and terminating in 1—3 flowers. Lower leaves, linear-obtuse, stiff, ⅛ of an inch or more long, smooth or slightly hairy; calyx lobes linear-oblong, 1—3 ribbed, glandular, hairy, ⅛ of an inch long; petals white, broad, equalling or exceeding the sepals. On high alpine slopes and summits, throughout the Rockies; flowering in June and July. RANUNCULACEÆ _Crowfoot Family_ Herbs or rarely climbing shrubs with acrid sap; leaves usually alternate without stipules; flowers usually showy, blue, white, yellow, or scarlet; sepals 3—15, generally soon falling away, often petal-like; petals about the same number or occasionally wanting; stamens many; carpels many or rarely solitary. [Illustration: Atragene columbiana Nutt. (⅔ Nat.) Purple Virgin’s-Bower.]