Low tufted herbaceous shrubs, with simple petioled stipulate leaves white-canescent beneath, and white or yellow, rather large perfect solitary flowers on slender scapes. Calyx persistent, not bracted, its tube concave, glandular-hirsute, 8-9-lobed. Petals 8 or 9, obovate, larger than the calyx-lobes. Stamens 00, inserted on the throat of the calyx; filaments subulate. Carpels 00, sessile, inserted on the dry receptacle; style terminal, persistent, elongated and plumose in fruit. Seed ascending, its testa membranous. [Name Latin, a wood-nymph.]

Three species, natives of the cold-temperate and arctic parts of the north temperate zone. Type species: Dryas octopetala L.

Flowers white; sepals linear.

Leaves oval or ovate, coarsely crenate.

1.

D. octopetala.

Leaves ovate, or ovate-lanceolate, subcordate, entire or nearly so.

2.

D. integrifolia.

Flowers yellow; sepals ovate; leaves crenate.

3.

D. Drummondii.

26 Dryas L Sp Pl 501 1753 626

1. Dryas Octopétala L. White Mountain Avens

Fig. 2284

Dryas octopetala L. Sp. Pl. 501. 1753.

Dryas chamaedrifolia Pers. Syn. 2: 57. 1807.

Stems prostrate, woody at the base, branched, 3'-6' long. Stipules linear, ad-nate to the petiole; leaves oval or ovate, coarsely crenate all around, green and glabrous above, densely white-canescent beneath, generally obtuse at each end, 1/2'-1' long; scape terminal, erect, 1'-5' long, pubescent; flower white, about 1' broad; sepals linear, acute or acutish, glandular-pubescent, persistent; style about 1' long, plumose and conspicuous in fruit.

Labrador and Greenland and throughout arctic America, south in the Rocky Mountains to Utah. Colorado, and to British Columbia. Also in arctic and alpine Europe and Asia. Wild betony. June-Aug.

1 Dryas Octop Tala L White Mountain Avens 627

2. Dryas Integrifòlia Vahl. Entire-Leaved Mountain Avens

Fig. 2285

Dryas integrifolia Vahl, Act. Havn. 4: Part 2, 171. 1798. Dryas tenella Pursh, Fl. Am. Sept. 350. 1814.

Similar to the preceding species, but the leaves are ovate or ovate-lanceolate, obtuse and often subcordate at the base, obtusish at the apex, entire or with 1 or 2 teeth near the base, the margins strongly revolute; flowers white, generally slightly smaller; sepals linear.

"White Hills of New Hampshire," collected by Prof. Peck, according to Pursh, Anticosti, Greenland; Labrador, west through arctic America to Alaska. June-Aug.

3. Dryas Drummóndii Richards. Drum-Mond's Mountain Avens

Fig. 2286

Dryas Drummondii Richards.; Hook. Bot. Mag. pl. 2972.

1830. Dryas octopetala var. Drummondii S. Wats. Bibliog.

Index 1: 281. 1878.

Similar to D. octopetala, the leaves crenate-dentate, but generally narrowed at the base. Scape floccose-pubescent, often taller; flower yellow, about 9" broad; sepals ovate, acutish, black glandular-pubescent.

On gravel, Gaspé, Quebec; Anticosti and Labrador, throughout arctic America, south in the Rocky Mountains to Montana and to Oregon. June-Aug.

3 Dryas Drumm Ndii Richards Drum Mond s Mountain A 628