378 POI.YGONACEAE 



Ijeavos mostly narrow ainl lancoolatc, joiiitcil upon a short prtiolo ailnate to tlie sliort sheath of 

 the scarious stipules; flowers in axillary chisters, the clusters either more or less sep- 

 arated or crowded into a terminal leafy spike; stamens mostly S, the filaments or some 

 of them often dilated at base; achene tr!((uetrous. — Subgenus AvicuLAniA. 

 Perennial and more or less suffrutescent. 



liCaves revolute; flowers several in a cluster, crowded at the ends of the branches. . . . 



11. P. paronychia. 

 Leaves plane; flowers 1 to 3 in each axil, less crowded. 



Loaves linear; dry foothills 12, P. hnlanderi. 



Leaves oblong or obovate ; alpine 13. P. shastcnse. 



Annuals. 



Plants prostrate; branches leafy to the ends 14. P. aviculare. 



Plants erect or ascending. 



Flowers in axillary clusters; leaves little reduced upwards. 



Achenes dull lo. P. ramoxissimum. 



Aehenes shiny Ifi. P. minimum. 



Flowers in very loo-se spilses; leaves nuich reiluced upwards; ]dants i/. to IV2 

 feet high. 



Flowers deflexed ; aehenes black, shining 17. P. dnu(ila.ni. 



Flowers erect; achenes brownish, dull 18. P. .iprrtjtdariacforme. 



Flowers in dense terminal leafy spikes; plants T{. to 4 inches high. 



Flowers greenish white; "achene brown" 10. P. imhriratum. 



Flowers whitish or rose-color; "achene black" 2(1. P. wal.'iouii. 



2. FJower.i .strictly solitarji in the axiln of the leave.<f or liractx. 

 Interno<li's in ours very short and the branches spike-like; stamens S; achene triquetrous; leaves 

 very narrow, not jointed to the lacerate sti|iule; oiirs slender wiry lirittle annuals. — 

 Subgenus Dubavia. 

 Sheaths conspicuously lacerate. 



Stems flowering above the base; sheaths lacerate into more or less bristle-Iike seg- 

 ments 21. P. ealifornirum. 



Stems flowering from v(-ry base; stipules cottony 22. P. parryi. 



Sheaths 2-parted, the segments sharply but shortly toothed 23. P. hidwelliaCi 



B. Leaves cordate. 



Flowers in loose panieled racemes; stamens S; achene tri(|uetrous; twining plants. — Subgenus 

 ItiiiiKKDYKi \ 24. P. eonrolvulu-.'i. 



1. P. bistortoides I'tii'sh. Stems sevor:il from a thick horizontal rootstock, 

 1 to 214 feet liigh, tlie leaves mo.stly basal, those above reduced and bract- 

 like; leaves erect, oblong to linear-oblong, 4 to 8 inches long, the petioles half 

 to as long; raceme dense, spike-like, % to IV2 inches long; flowers white, on 

 sh'iider pedicels. 2 to 4 lines long. 



High wot meadows in the Sierra Nevada. San Bernardino ]\lts. and North 

 Coast Ranges. East to tlie Kocky Mts, and far nortliward. 



Loes. — Mt. San Jacinto, 77o/( 23.-)S'; Hocketts Jtdws., Tulare Co.. TTnU <f- Baheoch .5fin4; 

 Giant Forest (Round Meadow was white with its flowers in ,lune. 1000), Jepson 708; Twin 

 Lakes, Alpine Co.. naii.icn Sl.T; Bear Valley, Nevada Co., Jc/i.toii ; Goosenest Mt.. Built r 

 9(i!); Morgan, Tehama Co.. 77n» <f Bnhrocl 4331; Sisson. TTnll rf- Baheock 4070; Shackelford 

 Canon. Chandler 1708; Modoc Co., M. S. Baker: Trinity Summit, Goddard 103; South YoUo 

 Bolly. Jepxon ; Snow Mt. (ace. Zoe, 4: 17.5); Sherwood Valley, Davy 'ACM. 



Refs. — Polygonum bistobtoide.s Pursh, Fl. 1: 271 (1S14), tv])e loe. Weippe, Idaho. Capt. 

 Lcieis; Piper, Contrib. U, S. Nat. Herb. 11: 230 (190(5) ; Small, Monog. N. Am. Polygonum. 28, 

 pi. 1 (1893). P. hktorta Wats. Bot. Cal. 2: 14 (1880), not L. P. cephalophornm Greene, 

 Pitt. 5: 198 (1903). type loc. Mt. Conness. 3 Aug., 1890, Harford. P. hernardinum Greene, 

 1. c. 199, type loc. Bluff Tjake, San Bernardino Mts., Pari.ih. Bi.ttnrla leptophylla Greene, 

 Leaflets. 1: 20 (1904). type loc. high Sierra Nevada. Bolander. 



2. P. alpinum All. Stems stout, erect, 2 to 7 feet high, arising from a 

 fleshy root stock, 1 to 2 inches in diameter; herbage glabrous or nearl.y so; 

 leaves ovate, acuminate. 3 to 6 inches long, the short petiole narrowly wing- 

 margined to the base; panicles terminnl. loose, nearly or quite leafless, 3 to 7 

 inches long; flowers white. 



Subalpine, Yosemite to Jit. Shasta and west to ^farble Mt. 



Locs.— Lake Tenaya. nail 4'- Baheoek 3035; TIetch-lTetchy, Jepson 3488; Silver Lake, 

 Hansen 314; Bonner Lake. Heller 7123; Bear Valley, Nevada' Co,, Jep.ion : Klamath Range, 

 Jcp.wn 2883. " 



Befs. — Polygonum alpinum All. Fl. Pedem. 2: 200. t. (iS. fig. 1 (1785). type European; 



