Parr 4, 1908] ROSACEAE 355 
brous above, sometimes white-tomentulose beneath, but never silky except on the veins; 
leaflets broadly obovate or nearly orbicular, 0.5-1 cm. long, coarsely crenate with rounded 
teeth ; stolons 1-6 dm. long, glabrous; peduncles 2-5 cm. long, glabrous; bractlets linear 
or lanceolate, about 2 mm. long; sepals ovate, about 4 mm. long; petals usually broadly 
oval, 8-12 mm. long ; achenes large, 2.5 mm. long, plump, not grooved. 
TYPE LOCALITY : Holsteinborg, Greenland. 
DISTRIBUTION : Arctic America, on the coast, extending south to Labrador ; also in Iceland, 
Norway, and Spitzbergen. 
ILLUSTRATIONS : Fl. Dan. #/, 1578 ; Mem. Dep. Bot. Columbia Univ. 2: pl. 97, f. 6-9. 
22. COMARUM L,. Sp. Pl. 502. 1753. 
Pancovia Heist.; Adans. Fam. Pl. 2: 294. 1763. 
Argentina Lam. Fl). Fr. 3: 118, in part. 1778. 
Aquatic perennials, with long creeping rootstocks and pinnate leaves. Inflorescence 
cymose. Hypanthium almost flat or slightly saucer-shaped, enlarging in fruit, more or less: 
tinged with red. Bractlets, sepals, and petals 5. Petals red, ovate, acuminate. Stamens 
20-25, inserted near the base of the receptacle. Filaments filiform, but rather stout. 
Anthers flat, cordate at the base, attached by the back, and opening by longitudinal mar- 
ginal slits. Receptacle hemispheric, enlarging in fruit and becoming ellipsoid or hemi- 
spheric and spongy. Pistils numerous. Styles lateral, filiform. Seeds amphitropous. 
Type species, Comarum palustre L. 
1. Comarum palustre L. Sp. Pl. 502. 1753. 
Fragaria palustris Crantz, Stirp. Austr.2:11. 1766. 
Potentilla palustris Scop. Fl, Carn. ed. 2. 1: 359. 1772. 
Argentina rubra Yam. Fl. Fr. 3: 120. 1778. 
Polentilla Comarum Nestler, Monog. Potent. 36. 1814. 
Comarum digitatum Raf. Fl. Tell. 2: 55. 1837. 
Comarum angustifolium parvifolium Raf. Aut. Bot. 170. 1840. 
Comarum angustifolium Raf. Fl. Tell. 2: 56. 1837. 
Comarum palustre villosum Pers. Syn. 2: 58. 1806. 
Comarum tomentosum Raf. Aut. Bot.170. 1840. 
Potentilla palustris villosa Lehm, Stirp. Pug.9: 44. 1851. 
Perennial, with a creeping rootstock; stem ascending, 2-5 dm. high, more or less hir- 
sute with short spreading hairs, somewhat glandular on the upper portion (in the variety 
villosum densely villous and with copious glands), subglabrous on the lower portion, some- 
what striate, brownish or reddish in color, shining; lower stipules brown, scarious and 
wholly adnate to the petioles; the upper with free tips, lanceolate or ovate, foliaceous ; 
lower leaves with petioles 3-10 cm. long, the upper subsessile, all pinnate, with 5-7 
more or less approximate leaflets, green above, paler and purple-veined beneath, sparingly 
hairy, in age glabrate, or in the variety vil/osum densely velvety on both sides when 
young; leaflets in the typical form elliptic or oval, mostly acute at both ends, with broad 
ovate teeth, in the more common American form (C. angustifolium Raf.) linear-oblong, 
5-8 cm. long and only 1-2 cm. wide, obtuse or rounded at the apex and with lanceolate 
teeth ; cyme leafy, few-flowered ; hypanthium in flower 7-8 mm., in fruit about 15 mm. in 
diameter, short-pilose and glandular-pubescent ; bractlets narrowly lanceolate, scarcely half 
as long as the broadly ovate to lanceolate, acuminate sepals, which are about 1 cm. long in 
flower and 1.5 cm. in fruit; petals, stamens, styles, and the inner side of the sepals dark- 
purple; petals spatulate or ovate, acuminate or acute, scarcely half as long as the sepals. 
TYPE LOCALITY: Europe. . . . : ; ; 
DISTRIBUTION : Northern and subalpine Europe and Asia; also subarctic and arctic America, 
from Greenland and Labrador to Alaska; the narrow-leaved form extending south to New Eng- 
land, Minnesota, Wyoming, and California. 
este ene Fl. Dan. pl. 636; Fl. Deuts. ed. 5, p2 2585; —the narrow-leaved form: 
Britt. & Brown, Ill. Fl. f. 237; Mem. Dep. Bot. Columbia Univ. 2: p/. 99; — the hairy form: Pluk. 
Phyt. 2: pl. 212, f. 2. 
23. DUCHESNEA J. E. Smith, in Rees, Cycl. 15: 
under Fragaria. 1810. 
Perennial, with a short rootstock and long prostrate stolons. Leaves ternate, with 
short-stalked leaflets. Flowers solitary from the axils of leaves on the runners. Hypan- 
