SAXIFRAGA.] . SAXIFRAGES. 139 



1. SAXIF'RAGA, L. SAXIFRAGE. 



Perennial, rarely annual herbs. Leaves various, radical and cauline ; 

 petiole sheathing. Flowers cymose, white or yellow, rarely red or purple, 

 honeyed, proterandrous. Calyx-tube free or partially adnate to the ovary ; 

 lobes 5, imbricate. Petals 5. Stamens 10, rarely 5, incurving and an- 

 thers opening in succession. Ovary superior or partially inferior, 2-lobed, 

 2-celled ; styles 2. Capsule 2-beaked, 2-valved between the beaks, many- 

 seeded. Seeds small, smooth or rough. DISTRIB. N. temp, and Arctic 

 zones, Andes ; species 160. ETYM. Saxum and frango, from some 

 species rooting into rocks and breaking them up. 



SECTION 1. Porphyr'ion, Tausch. Perennial. Stems trailing, leafy. 

 Leaves opposite, small, with a pore at the tip, ciliate. Flowers solitary, 

 subsessile. Sepal-s erect in fruit. 



1. S. oppositifo lia, L. ; tufted, leaves small 4-farious ovate-oblong. 

 Alpine rocks, from N. Wales and Yorkshire to Shetland ; ascends to near 4,000 



ft. in the Highlands ; N.W. and N. Ireland ; fl. April-May. Glabrous, dark 

 green, depressed. Stems 6-8 in., creeping. Leaves J in., 4-fariously 

 imbricate, thickened and obtuse at the tip, ciliate with stout bristles. 

 Flowers \ in. diam., sessile on short annual shoots, campanulate. Sepals 

 obtuse, connate to the middle. Petals obovate, bright purple. Capsule 

 free, f in. ; beaks diverging, subulate. DISTRIB. Arctic and Alpine Europe, 

 Asia (to W. Tibet) and America. 



SECTION 2. Micran'thes, Haw. (gen.). Perennial, stemless, scapigerous. 

 Radical leaves petioled. Cymes dense-fid. Sepals adnate to the base of 

 the carpels. Petals white. 



2. S. niva'lis, L. ; leaves broadly spathulate crenate-dentate. 



High alps, alts. 2,000-4,300 ft , of Snowdon, the Lake district, and the 

 Highlands ; Sligo ; fl. July-Aug. Glandular-hairy on the leaf-margins, 

 scape, bracts and pedicels, elsewhere glabrous. Rootstock small. Leaves 

 f-1 in. diam., subcoriaceous, red beneath; j> e tiole 1-2 in. Scape 3-6 in., 



simple. Flowers J in. diam., white, in capitate 4-12-] 

 Bracts linear. Calyx-lobes connate, purplish. Capsule with short divergent 

 beaks. DISTKIB. Arctic Europe, Silesia, N. Asia, N. America. 



SECTION 3. Hydat'ica and Arabidi'a, Tausch. Perennial, scapige- 

 rous. Stem short or 0. Cymes lax-fid. Sepals almost free, reflexed. 

 Petals white with 2 purple dots above the base. 



3. S. stella'ris, L. ; stemless, leaves rosnlate subsessile cuneate-lanceo- 

 late usually coarsely toothed, scape leafless, filaments subulate. 



Alpine and subalpine rills, from N. Wales and York to Caithness ; ascends 

 to 4,300 ft. ; Ireland ; fl. June-July. Glabrous or sparsely hairy. Rootstock 



