n9 POLYGONACE.E. Oxyiheca. 



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

 awnecl : segments uf tlio glamlular-pubescent i)erianth similar and equal : ovary 

 glabrous. °Only the following speeios. — T<.rr. Sc Cray, Revis. Eriog. in Proc. Am. 



Acad. viii. 190. , ^ 



* Bracts united only at base. 



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

 lon<' -d'abruu:^, w'ith scabrous-ciliate margin : bracts linear-oblong, acute without 

 awns 2 or 3 lines long : involucres shortly peilicelled, 4-cleft nearly to the l)ase, 

 the oblon"-lanceolate lobes nearly equal, acute without awns, a hue long : llowers 

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

 Proc. Am. Acad. xii. 273. 



Collected only by Mi^^ -1^- J- Bancroft, piobul.ly on Mount Diablo ; leniaikable for the total 

 absence of a\\ us. 



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

 or "less or sl.niter and less divided ; the scapedike stem usually 1 or 2 inches high : 

 leaves 'linear-oblanceolate, hirsute, i 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 U 

 lines Ion" (excluding the short awns), unecpially 3-4-lobed, rather lleshy, those in 

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

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

 shorter. — PI. fiambel. 1G9 ; lienlh. in DC. Piodr. xiv. 23; Torr. & Cray, 1 c. 

 0. apiculata, Miers, Linn. Trans, xxi. 144, t. 17. Bnsegnoa Chilensis, <C^ixy,\^\. 

 Chil. V. 292, t. 58. 



Ill dry canons from Noithwestern Nevada {Torraj, Watson) to Northwestern Wyoming, 

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

 iiowered, the involucres small. 



3 O Watsoni, Torr. ct (Iray, 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 rellexed, 

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

 awns e'longated, very shortly pedicelled, about 3-ilowered : llowers a third of a line 

 long, whit't'.; segmei'its oblong, entire. — Watson, Hot. King Exp. 311, t. 33, f. 5-7. 



Valleys of Northern Nevada, Watson. 



4. O. trilobata, Cray. Pesembling the last in bal)it, not glaucous : leaves 

 somewhat villous : llracts'ternate, oblong-lanceolate, awned, not rcHexed : involucres 

 broadly turbinate, r)-parted nearly to the ba.se, strongly nerved, U to 2 lines long, 

 with awns shorter than the lobes, on spreading pedicels 2 to 5 lines long, -^--J-ilow- 

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

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

 Am. Acad. xii. 83. 



San Bernardino County, rarry k Lanmon, 1876. 



* * Brads united Into a rounded concave perfoliate dish: 



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

 often redilisli : 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 \l lines long, with long awns, 4 - G-llowered : llowers white, 

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



In dry valleys of Northwestern Nevada (;r«/.so/,, /.,;,///(..// ) ; on the Mohave Unx-r (Palmer) ; 



5. rtah, Parrii. 



