ELATINACE.E. (WATER- WORT FAMILY.) 39 



* * * Perennial, with a thickened candex. 

 5. C. megarrhiza, Parry. Root fusiform, very large : leaves fleshy ; 

 radical ones petioled ; cauline lanceolate or linear-lanceolate, sessile : racemes 

 secund : flowers large, profuse, white with pinkish veins : petals obovate, 

 subemarginate. — Parry in Herb. Gray. 0. arctica, var. megarrhiza, of Bot. 

 King's Exp. and Fl. Colorado. High alpine, growing in crevices of the rock, 

 its large purple tap-root penetrating to a great depth. Mountains of Colorado 

 and the TJintas. 



5. SPRAGTJEA, Torr. 



Sepals orbicular-cordate. — A glabrous biennial ; with mostly radical fleshy 

 leaves and ephemeral flowers in dense scorpioid spikes umbellate-clustered on 

 a scape-like peduncle. 



1. S. umbellata, Torr. Stems several from a thickened root, 2 to 12 

 inches high : radical leaves spatulate or oblanceolate, on thick petioles ; the 

 cauline similar , but smaller, frequently scariously stipulate : an involucre of 

 scarious bracts subtending the dense capitate umbel of nearly sessile spikes : 

 flowers light rose-color : sepals very conspicuous, about equalling the petals. 



— Wyoming {Parry), Yellowstone Park (Coulter), and westward. Usually in 

 dry rocky or sandy localities. 



6. CALYPTRIDIUM, Nutt. 



Sepals broadly ovate or orbicular. Petals somewhat coherent at the apex. 



— Smooth prostrate diffusely branched annuals ; with alternate succulent 

 leaves and small ephemeral flowers in axillary or terminal, clustered or com- 

 pound, scorpioid spikes. 



1. C. roseum, Watson. Leaves oblong-spatulate, attenuate at base ; 

 radical leaves few or none : petals minute : capsule not exceeding the calyx. 



— Bot. King's Exp. 44, t. 6. W. Wyoming (Parry) and westward to 

 California. 



7. LEWISIA, Pursh. 



Sepals broadly ovate, unequal, persistent. Petals large and showy. Style 

 parted nearly to the base. — Low acaulescent fleshy perennials, cespitose, with 

 thick fusiform roots. 



1. Ii. rediviva, Pursh. Leaves densely clustered, linear-oblong, sub- 

 terete, smooth and glaucous : scapes but little longer, jointed at the middle, 

 and with 5 to 7 subulate scarious bracts verticillate at the joint : petals rose- 

 colored or white. — Arizona, Utah, Wyoming, Montana (in the Bitter Root 

 Mountains),, and westward. The specific name refers to the fact that the roots 

 are wonderfully tenacious of life. 



Order 13. ELATINACEJE. (Water-wort Family.) 



Low annuals, with membranous stipules between the opposite dotless 

 leaves, regular and mostly symmetrical flowers (2 to 5-merous), with 



