[Sidenote: =Cerastium behringianum= Cham. and Schl. _Alpine Chickweed._] Thick, silky-hairy below, with sticky hairs above; stems matted 1—3 inches high. Leaves small, oblong, ¼ of an inch long or less, rather thick, obtuse. Flowers ¼ of an inch or more broad; petals white, notched at the apex, sometimes little longer than the lanceolate sepals. In stony ground, alpine slopes and summits throughout the Rockies, flowering during summer. [Sidenote: =Alsine longipes= (Goldie) Coville. _Long-stalked Stitchwort._] Erect or ascending, tufted, simple or rarely sparingly branched, 3—12 inches high, smooth and shining. Leaves light green, lanceolate or linear-lanceolate, ½—1½ inches long, broad at the base. Flowers few, ¼—⅓ of an inch broad, terminal, on long, slender, erect pedicels; sepals ovate or lanceolate, acute; petals 2-cleft, exceeding the calyx. In moist open places throughout the Rockies, flowering in June. [Sidenote: =Alsine læta= (Richards.) Rydb. _Glaucous Stitchwort._] Low, smooth, or somewhat hairy, 1—4 inches high, very glaucous throughout, densely leafy at the base. Leaves keeled, lanceolate, awl-shaped to linear, rather stiff, ¼—½ an inch long. Flowers ¼ of an inch or more across; sepals lanceolate, acute, ⅛ of an inch long; petals notched, longer than the sepals; stamens showy, with scarlet anthers. In alpine meadows and moist grounds at high altitudes, throughout the region; flowering in July. [Sidenote: =Alsine borealis= (Bigel.) Britton. _Northern Stitchwort._] Erect or ascending, weak, much branched, smooth, or hairy above, 6—18 inches long. Leaves thin, lanceolate or oblong-lanceolate, ½—1½ inches long, acute, sessile, thin, margins slightly hairy or naked. Flowers small and inconspicuous in a leafy terminal compound head, ascending or spreading on slender pedicels; sepals ovate-lanceolate, acute; petals shorter than the sepals or none. In wet places at the lower altitudes throughout the Rockies; flowering throughout the summer from early June. [Illustration: _a_ Alsine borealis (Bigel.) Britton. Northern Stitchwort. _b_ Mœhringia lateriflora (L.) Fenzl. Blunt-Leaved Sandwort. (½ Nat.)] [Illustration: Arenaria capillaris nardifolia (Ledeb.) Regel. (⅔ Nat.) Rock Sandwort.] [Sidenote: =Sagina saginoides= (L.) Britton. _Arctic Pearl-wort._] Smooth, stems very slender and tufted, 1—4 inches high. Leaves 1⅛ to nearly ½ an inch long with a spiny tip. Flowers small, solitary or few together, at the end of the slender stem, about ⅛ of an inch broad; petals white minute, hardly exceeding the calyx. On rocks and moist sandy ground throughout the region; flowering in June. [Sidenote: =Mœhringia lateriflora= (L.) Fenzl. _Blunt-leaved Sandwort._]