polygonum POLYGONACEiE 581 



the branches, sessile, pitted on the upper surface, acute or acuminate at 

 base, with a broad 2 -winged midrib ocreae 6-10 lines long, silvery, early 

 lacerate into hair-like segments : riowers crowded into subspicate clusters 

 near the ends of the branches : calyx white to pink, about 3 lines long, 5- 

 parted to below the middle, the segments obovate or oblong: stamens 8, 

 included : style a line or more long, 3 cleft at the apex. On sandy banks 

 along the coast, Vancouver Island to California. 



P. Shastensis Brewer Gray Proc. Am. Acad, viii., 400. Glabrous 

 throughout : stems prostrate or ascending, 4-12 inches long, much branch- 

 ed: oblong to oblanceolate, 3-6 lines long, longer than the internodes, ses- 

 sile, acute at base: ocreae 2-3 lines long, 2-parted, the segments very thin 

 and silvery : flowers 2 or 3 together in the axils of the leaves : calx 2 lines 

 long, rose-color or red, 5- parted to near the base, the segments obDvate, 

 each with a dark rib: stamens 8, included; filaments strongly dilated at 

 base: style 3-parted, apparently formed by the splitting of the apex of the 

 narrowly oblong achene. Mount Mazama Oregon to the high peaks of the 

 Sierra Nevada Mountains. 



* * Annuals, rarely perennials, with striate stems, leafy through- 

 out : calyx colored upon the margins, becoming closely appressed to 

 the achene : style short. 



P. littorale Link in Shrad. Journ. i, 54. Annual or perennial, glab- 

 rous, bright green and glaucous: stems prostrate, 1-4 feet long, diffusely 

 branched : leaves oblong to oblanceolate, 3-12 lines long, generally acumin- 

 ate at base, conspicuously nerved, often crisped, short-petioled: ocreae 

 oblique, 2-3 lines long, 2 parted and silvery when young, at length lacerate 

 and brownish : flowers in clusters of 1-6 in the axils of the upper leaves : 

 calyx mostly green, 5-parted tc below the middle, the segments oblong: 

 stamens 8, included: style a line long, 3-parted to the base, included. 

 Brit. Columbia to California and across the continent. 



P. aviculare L. Sp. 362. Glabrous throughout and dull or bluish - 

 green : stems prostrate or ascending, 4-24 inches long, simple or branched : 

 leaves oblong to oblanceolate, 5-12 lines long, acuminate at base, not con- 

 spicuously nerved, subsessile or short-petioled: ocreae oblique, 2 lines long, 

 silvery, becoming lacerate in age: flowers in clusters of 2-5 in the axils of 

 the leaves : calyx mostly green, 5-parted to below the middle, the segments 

 oblong: stamens 5-8, included: style very short, 3-parted. Common in 

 yards and roadsides. 



P. erectum L. Sp. 363. Glabrous throughout: stem stout, erect or 

 ascending and somewhat spreading, 8-24 inches high, nearly simple to 

 much branched: leaves oval, oblong or obovate, 6-30 lines long, mostly 

 acuminate at base, sessile to short-petioled : ocreae 3-12 lines long: flowers 

 in clusters of several in the axils of the middle leaves : calyx greenish, over 

 a line long, 5-parted to below the middle, the segments oblong: stamens 6 

 or 7, included: style less than a line long, 3-parted. In sandy fields, east- 

 ern Oregon to Texas and Georgia. 



P. minimum Watson Bot. King 315. Somewhat scurfy but glabrous : 

 stem erect or spreading, 1-3 inches long, slender, simple or branching from 

 the base : leaves obovate to ovate or oblong, 3-8 lines long, acute or apicu- 

 late at the apex, acuminate at base, subsessile, not much reduced above: 

 ocreae about a line long, dentate-lacerate : flowers in clusters of several in 

 axils of all the leaves: calyx greenish, about a line long. 5-parted to near 

 the base, the segments oblong, the margins pale rose-color: stamens 5-8, 

 included. On the high mountain tops, Washington and Oregon to Cali- 

 fornia and Utah. 



* * Annuals with striate stems, the branches slender and virgate, 

 angular : leaves diminishing upward and becoming bract-like; the 



