32 POLYGONACE^E. Oxytheca. 



rosulate at the "base ; , bracts ternate, foliaceous and more or less connate, often 

 awned : segments of the glandular-pubescent perianth similar and equal : ovary 

 glabrous. Only the following species. Torr. & Gray, Eevis. Eriog. in Proc. Am. 



Acad. viii. 190. 



* Bracts united only at base. 



1. O. inermis, Watson. Low and slender : leaves broadly oblanceolate, an inch 

 long, glabrous, with scabrous-ciliate margin : bracts linear-oblong, acute without 

 awns, 2 or 3 lines long : involucres shortly pedicelled, 4-cleft nearly to the base, 

 the oblong-lanceolate lobes nearly equal, acute without awns, a line long : flowers 

 rose-colored, half a line long ; segments oblong, the inner smaller and retuse. 

 Proc. Am. Acad. xii. 273. 



Collected only by Miss M. J. Bancroft, probably on Mount Diablo ; remarkable for the total 

 absence of awns. 



2. O. dendroidea, Nutt. Very slender, diffuse and much branched, a foot high 

 or less, or stouter and less divided ; the scape-like stem usually 1 or 2 inches high : 

 leaves linear-oblanceolate, hirsute, to 1 1 inches long, acute : bracts unequal, with- 

 out awns, linear-oblong to linear, or oblong- ovate in the stouter form, the lower 

 half an inch long or less, the upper much smaller : involucres turbinate, \ to H 

 lines long (excluding the short awns), unequally 3 - 4-lobed, rather fleshy, those in 

 the forks on slender pedicels 1 to 4 lines long, the rest more nearly sessile : flowers 

 light rose-color, half a line long ; outer segments obovate, the inner narrower and 

 shorter. PI. Gambel. 169; Benth. in DC. Prodr. xiv. 23; Torr. & Gray, 1. c. 

 0. apiculata, Miers, Linn. Trans, xxi. 144, t. 17. Brisegnoa Chilensis, Gay, Fl. 

 Chil. v. 292, t. 58. 



In dry canons from Northwestern Nevada (Torrcy, Watson) to Northwestern Wyoming, 

 (Nuttall, Parry) ; also in Chili, the slender form with very numerous branches and many- 

 flowered, the involucres small. 



3. O. Watsoni, Torr. & Gray, 1. c. A span high or less, glaucous : leaves ob- 

 lanceolate, an inch long, glandular-pubescent : bracts apparently in pairs (one very 

 small or wanting), ovate to oblong-lanceolate, connate on one side and reflexed, 

 awned, half an inch long or less : involucres turbinate, 4-lobed, half a line long, the 

 awns elongated, very shortly pedicelled, about 3-flowered : flowers a third of a line 

 long, white; segments oblong, entire. Watson, Bot. King Exp. 311, t. 33, f. 5-7. 



Valleys of Northern Nevada, Watson. 



4. O. tlilobata, Gray. Eesembling the last in habit, not glaucous : leaves 

 somewhat villous : bracts ternate, oblong-lanceolate, awned, not reflexed : involucres 

 broadly turbinate, 5-parted nearly to the base, strongly nerved, 1 \ to 2 lines long, 

 with awns shorter than the lobes, on spreading pedicels 2 to 5 lines long, 3 - 4-flow- 

 ered : flowers light rose-color, a line long ; segments ligulate-oblong, 3-cleft, the 

 lanceolate lobes acuminate, slightly erose on the sides : ovary triangular. Proc. 

 Am. Acad. xii. 83. 



San Bernardino County, Parry & Lemmon, 1876. 



* * Bracts united into a rounded concave perfoliate disk. 



5. O. perfoliata, Torr. & Gray, 1. c. Diffuse, a span high or less, glaucous, 

 often reddish : leaves spatulate, ciliate, an inch long or less : lowermost bracts 3 or 



4, small, united only at base, the rest large and conspicuous, perfoliate and 3-awned, 

 net-veined : involucres nearly sessile in the forks, more narrowly turbinate, deeply 

 5-cleft or -parted, 1 to 1J lines long, with long awns, 4 - 6-flowered : flowers white, 

 nearly a line long. Watson, Bot. King Exp. 311, t. 34, f. 1-3. 



In dry valleys of Northwestern Nevada ( Watson, Lemmon) ; ou the Mohave River (Palmer) ; 



5. Utah, Parry. 



