SAXIFRAGACEAE. 1 89 



Leptarrhena amplexifolia (Stcrnb.) Ser. Rootstock stout, covered with 

 the old brownish leaf-bases; basal leaves oblong to obovate, serrate above the 

 middle, coriaceous, glabrous, green and shining above, pale beneath, 3-12 cm. 

 long; petiole stout and broad; stems 20-40 cm. high, bearing 1 or 2 small leaves; 

 inflorescence paniculate, glandular; sepals ovate; petals white, narrow, about 

 2 mm. long; carpels 8-10 mm. long, not diverging, usually purple. 



Common along alpine rivulets at about 1700 m. altitude in Washington 

 and northward to Alaska. 



250. SAXIFRAGA. Saxifrage. 



Chiefly perennial herbs; stem short or none; radical leaves 

 tufted; cauline mostly alternate; flowers perfect, solitary or in 

 cymes or cymose panicles; calyx 5-lobed, free or adhering to the 

 base of the ovary; petals 5, entire, perigynous; stamens 10, 

 perigynous; carpels 2, nearly distinct or united into a 2-celled 

 ovary; placentae axile; styles distinct; capsules 2-beaked, 2- 

 celled, sometimes forming two almost separate follicles. 



By some botanists divided into ten or more genera. 



Stems producing perennial branches, these densely beset 

 with small leaves. 

 Leaves coriaceous and evergreen, entire. 



Filaments clavate; leaves spatulate, obtuse, not cili- 



ate. 5. tolmiei. 



Filaments subulate; leaves lanceolate, ciliate. S. hronchialis. 



Leaves not coriaceous, thin, 3-5-lobed or cleft. 



Calyx united only at base; leaves cleft. 5. cespiiosa. 



Calyx united to the middle; leaves lobed. 5. adscendens. 



Stems not producing perennial leafy branches. • , 



Calyx campanulate; stems leafy. 



Leaves mostly 5-lobed; sepals obtuse. 5. dehilis. 



Leaves entire or 3-toothed; sepals acute. S. nuttallii. 



Calyx rotate; leaves all or mostly basal. 

 Leaves serrate or coarsely dentate. 



Petals dissimilar; leaves spatulate, serrate, short- 



petioled. 5. bongardi. 



Petals similar; leaves cordate or reniform, coarse- 

 ly toothed, long-petioled. 

 Caudex bulbous; herbage somewhat glandular; 



leaves usually doubly dentate. 5. mertensiana. 



Caudex not bulbous; leaves glabrous, simply 

 dentate. 

 Petals orbicular, clawed. S. odontoloma. 



Petals elliptic, not clawed. S. nelsoniana. 



Leaves entire or merely crenate, all basal. 



Leaves ovate or oblong, petioled, usually coarsely 

 crenate. 

 Filaments subulate. 5. riifidida. 



Filaments clavate. 5. marshallii. 



Leaves entire or nearly so, oblong-spatulate to 

 ovate. 

 Stems 30-60 cm. tall; flowers 7-9 mm. broad; 



leaves without petioles. 5. oregana. 



Stems 10-30 cm. liigh; flowers 6-8 mm. broad; 



leaves more or less distinctly petioled. 5. integrifolia. 



