In gravel and loose stony soil throughout the Rockies, especially abundant on river shores and flood-plains, like the previous species frequently forming mats of considerable size; flowering in June. [Illustration: _a_ Dryas octopetala L. White Mountain Avens. _b_ Dryas Drummondii Rich. Drummond’s Mountain Avens. (⅞ Nat.)] [Sidenote: =Rosa Macounii= Greene. _Macoun’s Rose._] Stems branched, 2—3 feet high, prickly. Leaves pinnate, leaflets large, ¾—1½ inches long, oval, coarsely toothed. Flowers solitary, on slender pedicels, bright pink, petals broadly obovate, an inch or more long, sepals entire with a long acuminate obtuse tip, persistent and erect in fruit, fruit globose, bright scarlet. The wild rose of the region, in open ground, on slopes, borders of woods, stream and river banks throughout the Rockies; flowering in late June and early July. POMACEÆ _Apple Family_ Trees and shrubs with alternate leaves, and regular, perfect flowers; calyx superior, 5-toothed; petals 5; stamens numerous; fruit a more or less fleshy pome. Leaves pinnate. =Sorbus.= Leaves simple, entire-toothed or lobed. =Amelanchier.= [Sidenote: =Sorbus sambucifolia= (Cham. and Schl.) Roem _Western Mountain-ash._] A small tree with smooth bark. Leaves pinnate, leaflets 5—15, ovate-lanceolate or oval, obtuse or short-pointed, serrate, smooth and dark green above, pale and usually more or less hairy beneath, especially along the veins, seldom over 2½ inches long. Flowers white, nearly ½ an inch across in a compound flat cyme, 2—4 inches broad; petals spreading, short-clawed, obovate; stamens numerous; fruit bright scarlet, more than ¼ of an inch in diameter. In moist stony ground throughout the region; flowering in June. [Sidenote: =Amelanchier alnifolia= Nutt. _North-western June-berry._] A shrub, soft-hairy when young, at length nearly smooth. Leaves thick, broadly elliptic or almost orbicular, very obtuse and often truncate at the apex, round or subcordate at the base; coarsely dentate above the middle. 1—2 inches long. Flowers in rather short, dense racemes, pedicels short; petals oblanceolate, ¼—¾ of an inch long, 2—4 times the length of the calyx; fruit purple when ripe and very sweet. On slopes at the lower altitudes throughout the region, flowering in June. DRUPACEÆ _Plum Family_ Trees or shrubs, the bark exuding gum. Leaves alternate, petioled, serrate, the teeth and petiole often glandular; flowers regular, perfect; calyx 5-lobed inferior, deciduous; petals 5, inserted on the calyx; stamens numerous, inserted on the petals; fruit a 1-seeded drupe. [Sidenote: =Prunus demissa= (Nutt.) Walp. _Western Wild Cherry._]