32 POLYGONACE.E. Oxyihecn. 



rosulate at the base ; bracts ternate, foliaceons 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 Avithout 

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

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

 leaves linear-oblanceolate, hirsute, | to 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, i to 1^ 

 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. ax)iculata, 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 Xorthern Nevada, Watson. 



4. O. trilobata, Gray. Pesembling 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 inTfoliate disk. 



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

 fiften 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 

 5cleft or -parted, 1 to 1| 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) ; on the Mohave River (Palmer) ; 



5. T^tah; Parry. 



