ELATINACEJE. (WATER-WOUT 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. C. 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 Uintas. 



5. SPRAGUEA, 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 oblauceolate, 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. LEWI SI A, 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. L. 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. ELATINACE^E. (WATER-WORT FAMILY.) 



Low annuals, with membranous stipules between the opposite dotless 

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



