254 SAXIFRAGACEiE. Saxifraga. 



Order XL VI. SAXIFRAGACE^. Juss. The Saxifrage Tribe. 



Sepals 4-5, united or nearly distinct. Petals as many as the sepals and alter- 

 nate with them, sometimes wanting. Stamens as many or twice as many as 

 the petals, and inserted with them into the throat of the calyx. Ovary either 

 free from the calyx or coherent with the tube, of 2 or sometimes of 3 - 5 or 

 more carpels, which are either jiartially or completely united, 1-celled with 

 parietal placentae, or with as many cells as carpels and the placentae in the 

 axis : ovules mostly numerous, anatropous : styles distinct or more or less 

 united. Capsules mostly with septicidal dehiscence. Embryo straight, in the 

 axis of fleshy albumen. — Herbs or shrubby plants, with alternate or opposite 

 leaves. Inflorescence various. 



Suborder Saxifrage^e. DC. 



^Estivation of the petals imbricate. Capsule usually beaked ; the distinct 

 summits of the carpels opening along the inner suture. — Herbs ; the base of 

 the petioles sometimes dilated, and resembling stipules. 



CONSPECTUS OF THE GENERA. 



1. Saxifraga. Sepals imbricate. Petals 5, entire. Stamens 10. Capsule S-celled below. Seeds smootji or wrinkled. 



2. Heuchera. Calyx campanulate, 5-cleft, imbricate. Petals 5, entire. Stamens 5. Capsule one-celled. Seeds 



muricate or hispid. 



3. MiTELLA. Calyx campanulate, 5-clcft, valvate. Petals 5, pinnatifid. Stamens 5 or 10. Capsule one-celled. Seeds 



shining. 



4. TiARELLA. Calyx campanulate, 5-parted, valvate. Petals 5, entire. Stamens 10. Capsule 2-cel!ed. Seeds smooth 



and shining. • 



5. Chrysosplenium. Calyx 4 - 5-lobcd, colored inside. Petals none. Stamens 8 - 10. Capsule 1-celled. 



1. SAXIFRAGA. Linn. ; R. Broivn in Parry'' s \st voy. suppl. p. 273 ; Endl. gen. 4634. 



SAXIFHAGE. 



[ From the Latin, saxtim, a rock, and frango, to break ; many of the species growing in the cracks or crevices of rocks.] 



Calyx free, or cohering with the base of the ovary : sepals 5, more or less united, imbricate 

 in asslivation. Petals 5, entire Styles 2. Capsule adhering to the calyx below, or free, 

 mostly of 2 more or less united carpels, 2-])eakcd, 2-celled below, many-seeded, opening 

 by a chink between the spreading beaks. Seeds smooth or wrinkled ; the testa not separable 

 from the nucleus. — Perennial (rarely annual) herbs. Radical leaves usually in a rosulate 

 cluster ; the cauline ones mostly alternate. 



