

378 MISC. PUBLICATION 42 3, U. S. DEPT. OF AGRICULTURE 



2. Fertile stamens 5; plants scapose, the leaves mostly basal (4). 



4. Staminodia none; flowers small, in racemes or cymose panicles; leaf blades 

 round-reniform, crenate or dentate; carpels 2, separate and divergent 



above 2. Heuchera. 



4. Staminodia in clusters alternating with the fertile stamens; flowers rela- 

 tively large, solitary on long peduncles; leaf blades oval or ovate, 

 acute or short-cuneate at base, entire; carpels 3 or 4, united. 



4. Parnassia. 

 1. Plants shrubby (5). 



5. Leaves alternate, those of the branchlets usually appearing fascicled, the 

 blades more or less deeply palmately lobed ; ovary wholly adnate to the 



calyx tube; fruit a juicy berry ; stems often spiny or bristly 9. Ribes. 



5. Leaves opposite, the blades entire or merely toothed; fruit a dry capsule, 

 partly free from the calyx; stems unarmed (6). 

 6. Sepals and petals 4 (rarely 5) ; leaf blades entire or shallowly few-toothed (7) . 

 7. Petals not clawed ; stamens many more than 8 (commonly 20 or more) , 

 the filaments terete, not lobed; capsule urceolate or obovoid, ab- 

 ruptly beaked, adnate to the calyx half or more of its length. 



5. Philadelphus. 



7. Petals long-clawed; stamens 8, the filaments broad and flat, 2-lobed, 



the anthers borne between the lobes; capsule ovoid or conic, atten- 

 uate-beaked, free except at base 7. Fendlera. 



6. Sepals and petals 5; stamens 10, the filaments not lobed (8). 



8. Leaf blades broad, thin, deeply and regularly crenate, long-petioled. 



6. Jamesia. 

 S. Leaf blades narrow, thickish, entire, sessile or nearly so. 



8. Fendlerella. 



1. SAXIFRAGA. Saxifrage 



Plants herbaceous; stems leafy or scapelike, erect, decumbent, or 

 prostrate; flowers perfect, regular, solitary or in simple or compound 

 cymes; calyx lobes and petals 5; stamens 10; carpels 2, united below 

 or nearly separate; ovary nearly free or partly inferior; follicles 

 beaked, divergent, many-seeded. 



Plants mostly of relatively high altitudes, in moist soil of coniferous 

 forests, usually among rocks. Two Arctic-alpine species are found 

 near the summit of the highest mountains in Arizona. 



Key to the species 



1. Foliage leaves all basal; flowers numerous, borne on scapes, these naked below 

 the inflorescence, the latter small-bracteate : Section Micranthes (2). 

 2. Inflorescence a very open panicle; leaf blades thin, commonly much shorter 

 than the petioles, orbicular or nearly so, more or less cordate at base, 



deeply crenate-dentate with numerous teeth 1. S. arguta. 



2. Inflorescence a contracted panicle of cymules; leaf blades thickish, commonly 



longer than the petioles, oblong, ovate, or rhombic, truncate or cuneate 



at base, shallowly crenate or crenate-dentate (3). 



3. Leaf blades lanate beneath with long, reddish hairs; petioles copiously 



ciliate with similar hairs; cymules lax, few-flowered, the inflorescence 



becoming relatively open 2. S. eriophora. 



3o Leaf blades glabrous or sparsely pubescent beneath; petioles sparsely 

 ciliate; cymules dense, subcapitate, the inflorescence remaining con- 

 tracted; scapes up to 30 cm. long; inflorescence up to 10 cm. long, 



the cymules solitary to several 3. S. rhomboidea. 



1. Foliage leaves not all basal, the stems leafy below the inflorescence, but the 

 cauline leaves sometimes much reduced (4) . 

 4. Leaf blades entire, conspicuously ciliate with thick, bristlelike hairs; plant 

 with slender, elongate, naked stolons ending in a tuft of small leaves; 

 leaves soft, those of the flowering stems scarcely reduced ; flowering stems 

 commonly solitary, erect, very leafy, bearing one or very few flowers; 

 petals yellow, broadly obovate, 6 to 9 mm. long: Section Leptasea. 



4. S. flagellaris. 



