POLYGONUM POLYGONACE.E 577 



end of the seed in one of its angles. Cotyledons foliaceous, slen- 

 der, accumbent or incumbent. 



SUBGENUS i BISTORTA Meisn. Polygon. 50. Perennial by a 

 bulb-like creeping or horizontal rootstock. Leaves radical and 

 cauline : ocreae membranaceous, cylindrical, naked, open, oblique 

 at the summit. Inflorescence a single terminal spicate raceme. 

 Flowers subtended by usually toothed bract- like ocreolae. Calyx 

 5-parted. Stamens 8. Style 3-cleft. Achenes 3-angled. Coty- 

 ledons accumbent. 



i r . bistortoides Pursh Fl. 271. Glabrous or sometimes with a fine 

 hispidulous pubescence on the under surface of the leaves, more or less 

 glaucous throughout : stems erect or assurgent, 10-25 inches long, slender, 

 simple : radical leaves oblong to oblong-lanceolate, 5-10 inches long, 3-18 

 lines broad, attenuate at base to a petiole 1-10 inches long, the midrib 

 rather broad and conspicuous on both sides; cauline leaves mostly lan- 

 ceolate, sessile or nearly so, subcordate, arising from near the summit of 

 the ocreae, all often with revolute margins and conspicuously nerved: 

 ocreae entire or somewhat broken about the oblique open summit, closely 

 clasping the stem: raceme oblong, 6-30 lines long, densely flowered, not 

 bulblet-bearing below: calyx about 2 lines long, light rose to white, 5-part- 

 ed, the segments oblong, faintly nerved. Subalpine and alpine parts of 

 the Cascade and Rocky Mountains, California to the Arctic regions. 



P. viviparum L. Sp. 360. Glabrous and more or less glaucous except 

 the under surface of the leaves : stems rather slender, erect, 6-18 inches 

 high, simple: radical leaves ovate or oblong and subcordate to linear-lan- 

 ceolate and attenuate at base, the blade 1-3 inches long, on petioles as long 

 or longer; cauline leaves lanceolate to linear: ocreae >-3 inches long, 

 slightly enlarged at the obliquely opened summit : raceme narrowly cyliri- 

 dric, 1-3 inches long, rather densely flowered above, bearing a number of 

 ovoid-conic bulblets at base: calyx about a line long, rose-color to white, 

 3-parted to near the base, the ovate or obovate segments 3-nerved. South- 

 ern Oregon to Alaska and the Atlantic States. 



SUBGENUS n ACONOGONON Meisn. Monogr. 53. Perennial by 

 a more or less elongated creeping or horizontal rootstock. Leaves 

 somewhat fleshy or coriaceous. Ocreae funnelform, membrana- 

 ceous, oblique, naked. Inflorescence consisting of terminal clus- 

 ters, racemes or paniculate racemes: flowers subtended by ocreolae. 

 Calyx 5-parted. Stamens 8. Style 3-cleft. Achenes triangular. 

 Cotyledons accumbent. 



P. alpinnm Allioni Fl. Pedim. ii, 206, t. 68. Bright green and glab- 

 rous or slightly pubescent throughout: stems stout, erect, 3-6 feet high, 

 channeled, more or less branched: leaves lanceolate, 1-9 inches long, acute 

 or acuminate, mostly tapering at base into short petioles, coriaceous : 

 ocreae funnelform, 6-18 lines long, oblique and 2-cleft, the segments acute 

 mostly glabrous, large and loose, brittle and early falling away: inflores- 

 cence consisting of compound or paniculate loosely-flowered racemes 1-2 

 inches long: ocreolae funnelform, oblique and shallow: calyx greenish or 

 whitish, I-IM lines long, 5-parted to near the base the segments obovate 

 or oblong, rounded. In wet places, alpine and subalpine, Washington to 

 California and Idaho. 



Tar. foliosum Small Bull. Torr Bot. Club xix, 360. Pubescent 

 throughout: stems stout, sparingly branched, hispid, : leaves ovate-lanceo- 



