SIBBALDIA. ROSACES. 175 



POTENTILLA. 



10 SIBBALDIA L. Gen. n. 393. 



Procumbent or depressed suffruticose plants with trifoliolate 

 leaves and rather small flowers on scape-like peduncles. Calyx 

 rather flat, 5-cleft and 5-bracteolate. Stamens 5, alternate with 

 the 5 petals, inserted into the margin of the villous disk which 

 lines the base of the calyx; filaments short. Carpels 5-10, raised 

 on short hairy stipes; styles lateral, attached near the base of 

 the ovary; stigma capitate, depressed. Seed ascending, amphi- 

 tropous. Radicle superior. 



S. procumbens L. Sp. 284. Somewhat villous : stems creeping, leafy at 

 the extremities : leaves trifoliolate; leaflets cuneiform, 3-12 lines long, 3-5 

 toothed at the apex : calyx-lobes 1-2 lines long ; bractlets linear and shorter : 

 petals much shorter, acute. Alpine and subalpine, from the Arctic 

 regions to California and the Rocky Mountains : Greenland, Labrador 

 and the White Mountains of N. H., Northern Europe. 



11 POTENTILLA L. Gen. n. 634. 



Herbaceous or suffruticose plants with pinnately or palmately 

 compound leaves, adnate stipules and axillary or cymous inflor- 

 escence. Calyx concave at the bottom, deeply 4-5-cleft, with 

 4-5 alternate bractlets. Petals 4-5, obtuse or retuse or obcord- 

 ate, deciduous. Stamens numerous, inserted into the margin of 

 the disk which lines the base of the calyx : filaments filiform or 

 subulate. Carpels numerous 1-ovuled, collected into a head on 

 the flattish persistent dry villous receptacle : styles lateral or 

 nearly terminal, deciduous : stigmas obtuse or somewhat capi- 

 tate : ovule always inserted next the insertion of the style and 

 accordingly either suspended or ascending. Radicle always su- 

 perior. 



1 Styles thickened and glandular toward the base : carpels 

 glabrous, numerous, sessile : inflorescence cymose. 



* Style attached below the middle of the ovary : disk thickened 

 and pentagonal ; stamens 20 -30, in one row on the margin of the 

 disk ; herbaceous perennials with pinnate leaves and glandular-vil- 

 lous pubescence. 



P. glntinosa Nutt. T. & G. Fl. i, 446, under P. fissa var. Stems stout, 

 erect, simple, striate, 1-4 feet high: radical leaves 7-11-foliolate 4-12 

 inches long, usually long-petioled ; stipules ovate, entire or incised ; leaf- 

 lets rounded or subrhomboidal, incised or densely serrate, the terminal 

 one 1-3 inches long: inflorescence loosely and regularly dichotomous, 

 forming an almost flat-topped cyme 6-8 inches broad in fruit; calyx 

 densely pubescent, the acute sepals 3-4 lines long; bractlets much smaller; 

 petals rounded obtuse, 3-5 lines long, clear yellow: achenes very broadly 

 oblique-ovoid, obtuse, distinctly carinate on the back above the middle, 

 the sides marked with numerous rather coarse simple or forked veins. 

 On stony hills, Vancouver Island to Oregon and Idaho. 



P. ciliata. Loosely pilose throughout : stems cespitose, slender, 

 10-12 inches high, from short creeping rootstocks: radical leaves 4-6 

 inches long: stipules linear to obovate, 4-6 lines long, more or less lacer- 

 ate: leaflets 5-9, -with 2-6 small ones interspersed, mostly obovate with 

 cuneate base, 4-12 lines long, coarsely lacerate toothed: flowers large, in 

 a rather close corymbose cyme; sepals ovate, acuminate, 4-6 lines long, 



