ROSE FAMILY 119 



stem few-leaved or scapiform; stamens 5; petals yellow or yellowish, clawed. 

 CjTne corymbiform; hj-pantliium cup-shaped. 



Bractlets linear; stem decimibent. 2. I. utahensis. 



Bractlets oblong or lanceolate; stem erect. 3. /. mutabilis. 



Cyme subcapitate; hypanthium campanulate. 4. I. Gordonii. 



Leaflets comparatively few. obovate, merely incised. 5. I. beneolens. 



11. COMARELLA Rydb. i. C. sabulosa. 



12. POTENTILLA L. Cinquefoil, Five-finger. 



Cymes very leafy, many-flowered; annuals or biennials, rarely short-lived perennials; 



styles fusiform and glandular at the base. I. Supinae. 



Cymes not very leafy, generally rather few-flowered; perennials with rootstocks. 

 Leaves digitate. 



Basal leaves 5-9-foliolate. 



Basal leaves without an additional pair of leaflets on the petioles. 

 Plants more than 2 dm. high. 



Leaves green on both sides, sparingly hairy, not at all tomentose. 



II. XUTTALLI.A.NAE. 



Leaves either densely hairy or more or less tomentose beneath. 



Leaflets merely crenate or cut-toothed, the tootlung not extending 

 half-way to the midrib. 



Leaflets densely pubescent beneath, if at all tomentose, the 

 tomentum hidden under the long hairs, green and sparingly 

 pubescent on the upper side. II. Nuttallianae. 



Leaflets principally tomentose beneath, only slightly hairy. 



V. Graciles. 

 Leaflets cleft more than half-way to the midrib into Linear, oblong, 

 or lance-oblong di\dsions. 

 Stems a.scending or decumbent at the base; stem-lea vas few, 



reduced, with 3-5 leaflets. III. Candidae. 



Stems leafy; most of the stem-leaves 7-foliolate. 



IV. Pectinisectae. 

 Plants less than 2 dm. high. 



Leaves neither tomentose nor silky, green. VII. Aure.\e. 



Leaves tomentose or silky, at least beneath. VIII. Concixnae. 

 Basal leaves digitately 5-foliolate, with an additional pair of smaller leaflets 

 on the petiole. VI. Subjug.'VE. 



Basal leaves 3-foUolate. 



Leaves more or le.ss tomentose beneath. IX. Niveae. 



Leaves not tomentose. X. Frigidae. 



Leaves odd-pinnate. 



Style much longer than the mature achene, fiUform. 



Leaves with 1-3 more or less appro.ximate pairs of leaflets ; plants low. 

 Leaves not at all tomentose. 



Style subterminal. VII. Aure.\e. 



Style attached below the ape.x of the achene. XI. Brevifoliae. 



Leaves more or less tomentose beneath. XII. Rubricaules. 



Leaves with 3-13 pairs of leaflets; plants usually comparatively tall. 

 Leaves grayish or whitish, silky or tomentose, at least beneath. 



XIII. Leucophyllae. 

 Leaves green on both sides or merely strigose. XIV. !Multijugae. 



Style not longer than the mature achene, thickened and glandular below; leaves 

 usually more or less tomentose beneath. XV. IMultifidae. 



I. Supinae. 

 Achenes with a corky gibbosity on the upper suture; leaves all pinnate with 3-5 pairs of 



leaflets. 1. p. paradoxa. 



Achenes not gibbous. 



Lower leaves pmnate with 2 approximate pairs of leaflets, the upper ternate; stem 



strict; inflorescence cymose. 2. P. rivalis. 



Leaves all digitate; the basal ones rarely pinnate in P. monspeliensis. 

 Leaves ternate. 



Petals about half as long as the sepals; achenes whitish, smooth; h^TJanthium 

 in fruit 5 mm. wide or less. 

 Stem slender; petals cuneate or obovate; sepals and bractlets 3-4 mm. long. 

 Stem with diffuse, spreading branches; leaflets cuneate; inflorescence 



cjTnose. 3. P. millegrana. 



Stem with erect or strongly ascending branches; inflorescence inclined 

 to be falsely racemose; leaflets broadly obovate; plant decidedly 

 glandular-puberulent. 4. P. biennis. 



Stem stout; petals obcordate; sepals and bractlets 5 mm. long; plants 

 densely glandular. 5. P. Kelseyi. 



Petals equalling the sepals or nearly so ; hj-panthium in fruit about 7 mm. wide; 

 stamens 15-20. 6. P. monspeliensis. 



Lower leaves digitately 5-foliolate, or ternate with the lateral leaflets 2-cleft to 

 near the base; stamens 5. 7. P. pentandra. 



II. Nuttallianae. 



Calyx and leaves more or less glandular-atomiferous ; whole plant yeUowish or brownish 

 green; leaves with strong ribs. 



