BUCKWHEAT T AMII.V. 159 



Plants 1 to 2 ill. high, flowering even from the base; leaves 1 to 'i lines long 

 ^, , ^ , , 6. P. Parriii. 



Flowers in dense splcate racemes (usually geminHte or paniculate), with smnll 

 acarious bracts; calyx 5-parted, appressed to the triangular or lenticular 

 achene; stamens 4 to 8, fllamtnts fililorm; leaves ample, not jointed to the 

 petiole. — Subgenus Pbssicarh. 

 Racemes solitary or sometimes 2; flowers red; stamens 5, exserled; nehene 

 lenticular; mostly agnatic perennials. 

 Sheathing stipules neither fringed at summit nor with a spreading margin. 

 Leaves mostly elliptical or oblong; spikes oblong or ovate. % to lin. long 



7. P. amphiblum. 

 Leaves ovate-lanceolate; spikes more elongated, 1 to 3 in. long 



8. P. Muhlenbergii, 

 Sheathing stipules ciliate-fringed at summit and with a spreading foliaceous 



border 9. P. HaHmirjhtii. 



Racemes several to many, geminate or more or less paniculate; stamens 6 to 

 S, included; achene either lenticular or triangular. 

 Sheathing stipules naked in age; racemes often drooping; sepals white or 



flesh-color; stamens 6; annual 10. P. lapathifolium. 



Sheathing stipules fringed witli bristles; racemes erect. 

 Sepals pink, red orgieeni^h; racemes not interrupted; stamens generally 



6; annual 11. P. Persicaiia. 



Sepals greenish and glandular-dotted; racemes Interrui'ted; stamens 8; 



perennial of marshy places . . 12. P. ptmcialum. 



Flowers in loose panicled racemns; stamens 8; achene triangular; leaves 

 cordate: twining plants.— Subgenus Timaeia. 

 Annual . . . . . . ... 13. P. Convolvulas. 



1. P. Paronychia C. & S. Stems suffrutesoent, prostrate oi- 

 ascending, 1 to 3 ft. long; brandies leafy above, below clothed with 

 old sheaths; sheaths large, 4 to 6 lines long, brown and 5-nerved, the 

 margin freely lacerate above, persistent, the segments becoming hair- 

 like in age; leaves linear-lanceolate, 5 to 8 or 11 lines long, acute, the 

 margin rc\olute; flowers about 3 in an axil, on short pedicels, densely 

 crowded at the ends of the branches in short more or less leafy spikes; 

 sepals rose-color, veined with green or brown, 3 lines long, oblong- 

 obovate; stamens 8; styles as long as the ovary; achene smooth and 

 shining, 2 lines long or more. 



Sandy hills near the coast: San Francisco and northward. 



2. P. Bolanderl Brewer. Taproot woody and strong, either with 

 a conspicuous crown or Avith horizontally spreading or prostrate 

 suifrutescent branches 4 or 5 in. long; stems of the season numerous 

 and erect, either arising from the woody crown or from the sufFrutes- 

 cent branches, 5 to 10 in. high, slender, simple, with short strict 

 leafy branchlets towards the top; sheathing stipules scarious, 2-lobed; 

 the lower lobe finely lacerate, persistent; leaves narrowly linear to 

 subuhite, acute or cuspidate, 2 or 3 lines long, not revolute; flowers 1 

 or 2 in the axils on the branchlets, involucrate with a sheaf-like 

 scarious bract on the joint of the very short pedicel, IJ lines long; 

 calyx 5-parted; sepals white or rose-color, with a green midrib, oblong- 

 ovate, slightly spreading; stamens 8 or 9, included; styles 3-parted; 

 achene triangu'ar. 



On rocky outcroppings, mostly in the lowest foothills; known only 

 from the Mavacamas Range and parallel chains: Suscol Hills; Hood's 

 Peal<; east of Napa City, and northward to the La Jota Plateau on 

 Howell Mountain. July-Sept. 



