254 SAXIFRAGACE^. Saxifraga. 



Order XL VI. SAXIFRAGACEiE. 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 partially or completely united, 1 -celled with 

 parietal placentae, or with as many cells as carpels and the placentfE 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 SAXiFRACEiE. 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 2-cclled below. Seeds smooth or wrinkled. 

 3. Heuchera. Calyx campanolate, 5-cleft, imbricate. Petals 5, entire. Stamens 5. Capsule one-ccUed. Seeds 

 muricatc or hispid. 



3. MiTELLA. Calyx campanulatc, 5-cleft, valvatc. Petals 5, pinnatifid. Stamens 5 or 10. Capsule one-celled. Seeds 



shining. 



4. TiARELLA. Calyx campanulatc, 5-partcd, valvate. Petals 5, entire. Stamens 10. Capsule 2-cclIed. Seeds smooth 



and shining. 



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



1. SAXIFRAGA. Linn. ; R. Brown in Parry''s Ist voy. suppl. p. 273 ; Endl. gen. 4634. 



SAXIFRAGE. 



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



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

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

 mostly of 2 more or less united carpels, 2-beaked, 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. 



