SAXIFRAGE FAMILY 111 



Flower-stalk axial, from a slender bulbiferous rootstock; gynoecium 3-carpel- 



lary. 2. Lithophragma. 



Flower-stalk a lateral sboot from a stout scaly rootstock; gynoecium 2-carpel- 

 lary. 

 Inflorescence racemose. 



Petals pinnately cleft or pinnatifld. 



Hypanthium deeply campanulate or urn-shaped, deeper than the 

 length of the sepals; capsule tapering into a beak. 



3. Tellima. 

 Hypanthium saucer-shaped or open campanulate, shallower than 



the length of the sepals ; capsules abruptly beaked or beakless. 

 Ovary more than half superior; disk inconspicuous; stigmas 

 entire, terminating distmct styles. 

 Stamens 10; placentae almost basal, bearing few ovules. 



4. MiTELLA. 



Stamens 5; placentae parietal, bearing many ovules. 



5. MITELLASTRA. 



Ovary wholly inferior, covered with the prominent disk; stigmas 

 sessile, 2-lobed; stamens 5. 6. Pectlantia. 



Petals entire, toothed or 3-cleft above; stamens 5. 



Hypanthium campanulate during anthesis; ovary half inferior. 



7. OZOMELIS. 



Hypanthium turbinate during anthesis; ovarv almost wholly in- 

 ferior. 8. CONIMITELLA. 

 Inflorescence paniculate; stamens 5; petals broadened upward. 



9. Heuchera. 

 Gynoecium of 2 very unequal carpels. 10. Tiaeella. 



Placentae axial. 



Hypantluum well-developed, and accrescent, at maturity longer than the sepals. 

 Stamens 5. 



Plants with short bulblet-bearing rootstocks; flower-stalk axial. 



Ovary half inferior; blade of the basal leaf ternately divided; stamens 



borne on the outer edge of a thickened disk. 11. Hemieva. 



Ovary two-thirds inferior or more; blade of the basal leaf merely crenate; 

 disk obsolete. 12. Suksdorfia. 



Plants with horizontal rootstocks; flower-stalk a lateral shoot. 



Sepals imbricate; petals marcescent; seeds winged. 13. Suli.ivantia. 

 Sepals valvate; petals deciduous; seeds wingless. 14. Therofon. 

 Stamens 10. 



Petals clawed; styles partially united; plants with thick rootstocks. 



15. Telesonix. 

 Petals clawless; styles distinct; plants with slender rootstocks, often with off- 

 sets. 



Plants without caudices, producing only annual flowering stems. 



16. Saxifraga. 

 Plants with perennial very leafy caudices, often with offsets, the flowering 



stems very different from the caudices. 

 Leaves of the caudex with lobed blades, the margins poreless. 



17. Muscaria. 

 Leaves of the caudex with serrate blades, each tooth with an encrusted 



pore. 18. Chondrosea. 



Hypanthium only sUghtly developed, unchanged at maturity, or if slightly accres- 

 cent, then flat and plants acaulescent. 

 Leaves alternate, sometimes all basal. 

 Plants acaulescent. 



Corolla essentially regular, the petals about equal in shape and length. 



19. Micranthes. 

 Corolla irregular, except sometimes that of the terminal flower, 3 of the 

 petals with blades of an ovate or lanceolate type and 2 of them narrower 

 and longer. 20. Spatulabia. 



Plants caulescent. 



Leaves without stipules. 



Carpels distinct; leaf-blades toothed. 21. Leptarrhena. 



Carpels partially united; leaf-blades entire or rarelv with 3 apical tooth- 

 like lobes. 22. Leptasea. 

 Leaves with reniform or orbicular, shallowly lobed blades and wing-like 

 stipules at the base of the petioles. 23. Heterisia. 

 Leaves opposite, except sometimes on the flower-stalks. 24. Antiphylla. 



1. CHRYSOSPLENIUM (Tourn.) L. Golden Saxifrage, 



Water Carpet. 



Leaves all alternate; flowers clustered near the ends of the stems; stamens 4. 



1. C. tetrandrum. 

 Lower leaves opposite; flowers solitary in the leaf-axils; stamens mostly 8. 



2. C. americanum . 



2. LITHOPHRAGMA Nutt. Star-flower, Prairie Star. Woodland Star. 



Hypanthium campanulate or hemispheric, mostly rounded at the base, adnata only to 

 the base of the ovary. 



