500 FLOKA. 



natc. Style lateral, filiiorm; achenes turgid, villous; seed ascending and amphit- 

 ropous; otherwise as in Potentilla. A mcnotypic genus. 



i. Sibbaldiopsis tridentata (Soland.) Rydb. Three-toothed Cinquefoil. 

 (I. F. f. 1933.) Caudex woody, creeping; branches of the year erect, 3-30 cm. 

 high, pubescent. Stipules lanceolate, entire; leaflets cuneate, 3-toothed or some- 

 times 2-5 -toothed at the truncate apex, dark green and shining above, pale and 

 minutely pubescent beneath; flowers 1-6, in a terminal cyme, about 1 cm. broad; 

 bractlcts shorter and narrower than the ovate acute calyx-lobes; stamens about 20. 

 [Potentilla tridentata Soland.] In rocky places, especially on mountains, Green- 

 land to N. J., on the southern Alleghanies, shores of Lake Superior, and west to 

 the Canadian Rocky Mts. June-Aug. 



:i. SIBBALDIA L. 



Depressed alpine or arctic plants, with alternate mainly 3-foliolate stipulate 

 leaves, and cymose flowers. Calyx slightly concave, 5-lobed, 5-bracteolate, per- 

 sistent. Petals 5, oblong or spatulate, much smaller than the calyx-lobes, yellow. 

 Stamens 5. opposite the calyx-lobes, inserted on the margin of the villous-pubescent 

 disk. Carpels 5-10, on short pubescent stipes; style lateral, filiform. Achenes 

 5-10, glabrous. [Named in honor of Robt. Sibbald. a Scotch naturalist.] About 

 5 species, natives of the colder parts of the north temperate zone. 



1. Sibbaldia procumbens L. Sibbaldia. (I. F. f. 1938.) Densely tufted; 

 stem decumbent or creeping, less than 1 dm. long. Stipules membranous, lanceo- 

 late or ovate-lanceolate, adnate; leaves 3-foliolate; leaflets cuneate, 3-5 -toothed at 

 the apex, pubescent with scattered hairs on both sides, resembling in outline those 

 of Sibbaldiopsis tridentata; flowers yellow, 3-5 mm. broad, numerous; petals 

 spatulate, very small; calyx-lobes oblong-ovate, acute, longer and broader than 

 the bractlets. White Mts.; Mt Albert, Quebec; Lab., Greenland to Alaska, 

 south in the Rocky Mts. to Utah and Colo. Also in Europe and Asia. Summer. 



12. FRAGARIA L. 



Perennial acaulescent herbs propagating by runners, with basal tufted petioled 

 3-foliolate leaves, and sheathing membranous stipules. Flowers white, corymbose 

 or racemose on erect scapes, polygamo-dioecious, the pedicels often recurved. 

 Calyx persistent, its tube obconic or turbinate. 5-bracteolate, deeply 5-lobed. 

 Petals 5, obovate, short-clawed. Stamens oc ; filaments slender. Carpels cc . in- 

 serted on a glabrous convex or elongated receptacle, which becomes fleshy or pulpy 

 in fruit; styles lateral. Achenes oo , minute, dry, crustaceous. Seed ascending 

 and amphitropous. [Latin, fragu/n, strawberry, signifying fragrance.] About 25 

 species, natives of the north temperate zone and the Andes of S. Am. Besides the 

 following, 15 others occur in western N. Am. 



Achenes imbedded in pits on the fruit. 



Hairs of the scape and petioles mostly divaricate: leaflets generally petiolate. 



Leaflets broadly oval or obovate; fruit globose or ovoid. x. /■'. Virginiana. 

 Leaflets oblong' or narrowlv obovate : fruit oblong-conic. 2. F, Cajiade?isis. 

 Hairs of the scape and petioles Oppressed ; leaflets subsessile. 3. F. 7 errae-noiae. 

 Achenes borne on the surface of the fruit ; leaflets subsessile. 



Stout; leaflets thickish; plant naturalized ; fruit ovoid to hemispheric. 



4. F. vesca. 

 Slender ; leaflets thin; native plant; fruit ovoid to conic. 5. F. Americana. 



1. Fragaria Virg-iniana Duchesne. Virginia or Scarlet Strawberry. 

 (I. F. f. 1908.) Rather stout, tufted, dark green, villous-pubescent. Leaflets 

 thick, obtuse, dentate-serrate, the terminal one generally cuneate. the lateral in- 

 equilateral at the base; scape equalling or shorter than the leaves; hairs of the 

 pedicels mostly appressed; calyx-lobes, at least of the sterile flowers, erect at ma- 

 turity. In dry soil. Prince Edward Island to Minn., Ind. Terr, and Ga. April-June. 



Fragaria Virginiana Grayina (Vilm.) Rydb. Plant coarse and hairy ; hairs of pedi- 

 cels divaricate. Ohio to Kans. [F. Virginiana Illinoetisis Gray.] 



Fragaria Virginiana austrilis Rydb. Smaller and more hairy, 3-8 cm. high ; leaflets 

 ynly 2-4 cm. long, almost sessile; sepals broad, acunnuate. Ya. to N. C. and La, 



