48 POLYGONE^:. 



5. OXYTHECA, Nutt. Slender annuals, glandular-pubescent (not 

 tomentose), with a rosulate basal tuft of leaves and a repeatedly dicho- 

 tomous paniculate inflorescence. Bracts of the flowering branches foli- 

 aceous, more or less connate. Involucres small, few- flowered, more or 

 less distinctly pedicellate, the lobes awn-tipped or unarmed. Perianth 

 6-parted, usually glandular-pubescent on the outside, the segments 

 alike. Stamens 6. Achene commonly lenticular. 



1. 0. inermis, Wats. Slender and low, 36 in. high, rather diffuse: 

 leaves broadly oblanceolate, 1 in. long, glabrous except the scabrous- 

 ciliate margins: bracts linear-oblong, acute, awnless: involucres short- 

 pedicelled, 4-cleft almost to the base, the oblong-lanceolate lobes 1 line 

 long, acute but awnless: fl. rose-color, ^ line long: achenes obtusely 

 triangular. Supposed to have been found originally on Mt. Diablo, but 

 better known from beyond our limits. 



2. 0. hirtiflora. (Gray), Greene. Glandular-puberulent and viscid, 

 6 in. high, erect, cymose-pauiculate above: leaves 1 in. long, oblong- 

 spalulate, with scabrous-ciliate margins and a broad red midvein: bracts 

 hispidulous, oblong, % i n - l n g or less, acutish: involucres awnless, ^ 

 line long, on slender erect or nodding pedicels 13 lines long: fl. 35, 

 very hirsute, rose-red, % line long. Summits of Mt. Diablo and Mt. 

 Hamilton. 



6. CHORIZltfTHE, R. Er. Dichotomous annuals with few and 

 mostly basal leaves; the branches with ternate bracts at the nodes. In- 

 volucres 1 3 flowered, sessile, more or less tubular, coriaceous or chart- 

 aceous, often corrugated or reticulate, 3 - 6-angled or -ribbed, with as 

 many cuspidate or rigidly awned teeth or segments. Flowers rarely 

 exserted, 6-parted or -cleft; bractlets minute or obsolete. Stamens 9 

 (rarely 6 or 3). Achenes triangular. 



*Villous or hirsute; involucres usually clustered, 6-angled and sulcate, 



the teeth cuspidate; bractlels obsolete: perianth 6-cleft, the 



stamens inserted at or near its base. 



4 Erect or erect-spreading ; involucres mostly in dense cymose clusters. 

 M- Margins of involucral lobes scarious. 



1. C. membranacea, Benth. Floccose-tomentose, erect, sparingly 

 branched, with long internodes and leafy nodes, % 2 ft. high: leaves 

 linear, acute, 12 in. long: bracts similar to the leaves but cuspidate: 

 heads sessile, solitary or few upon the branches: involucres tomeutose, 

 2 2^ lines long, the limb at length dilated and with uucinate teeth: 

 tube contracted in the middle: perianth villous, becoming 1* lines long, 

 6-parted, the segments oblong or spatulate: achene broadly triangular 

 and rostrate-attenuate. In the Coast and Mt. Diablo ranges. 



