Placentæ axial. Base of the calyx well developed, at maturity longer than the sepals. Stamens 5, plant with short bulblet bearing rootstock. =Hemieva.= Stamens 10. Plants without caudices; only producing annual flowering stems. =Saxifraga.= Plants with perennial leafy caudices, often with offsets. =Muscaria.= Base of the calyx only slightly developed, unchanged at maturity. Leaves alternate, sometimes all basal. Plants stemless. Corolla regular, petals about equal in shape and length. =Micranthes.= Corolla irregular petals of different shape and length. =Spatularia.= Plants with stems. Carpels distinct; leaf-blades toothed. =Leptarrhena.= Carpels partially united; leaf-blades entire. =Leptasea.= Leaves opposite except sometimes on the flower-stalks. =Antiphylla.= [Sidenote: =Chrysosplenium tetrandrum= Th. Fries. _Golden Saxifrage._] Perennial with a slender creeping rootstock; stems 1½—6 inches high, branched above. Leaves alternate, the lower ones on petioles 1—2 inches long; blades thick, reniform, ½ an inch or less wide, crenate with 3—5 broad teeth, shining above, paler beneath, upper ones larger and more or less wedge-shaped. Flowers in small clusters in the axils of the upper leaves; sepals 4; stamens 4 opposite the sepals. In shaded damp ground in the wooded areas through the Rockies at an elevation of 5000 to 6000 feet, where it often forms dense green carpets, the inconspicuous little flowers coming into blossom in June. [Sidenote: =Lithophragma parviflora= (Hook.) Nutt. _Lithophragma._] Stems 4—12 inches high, slightly glandular-hairy, from a slender creeping rootstock with rosy bulblets. Leaves palmately divided to the base into 3—5 divisions, ½—1 inch long, twice ternately cleft into oblong or linear divisions; lower ones on petioles 1—2 inches long; stem leaves 1 or 2 similar, sessile. Flowers 3—8 in a slender raceme, base of the calyx and sepals ⅛ of an inch long; petals pure white, deeply 3—5 cut into narrowly oblong divisions. On grassy slopes and gravelly places throughout the Rockies; flowering in June. [Sidenote: =Tellima grandiflora= (Pursh.) Dougl. _Tellima._]