34 FLORA. 



23. Polygonum maritimum L. SEASIDE KNOTWEED. (I. F. f. 1340.) 



Perennial or sometimes annual, glaucous, glabrous; root usually deep, woody; stem 

 prostrate or ascending, branched, 2-5 dm. long. Leaves ovate or oblong, mostly 

 equalling or longer than the internodes, 0.5-2.5 cm. long, fleshy, veined beneath, 

 somewhat rugose above, conspicuously jointed to the ocreae, the margins often 

 revolute; ocreae large, silvery, at length lacerate, becoming brown at the base; 

 flowers 1-3 together in the axils; calyx white or pinkish; stamens 8; style short, 

 3-parted; achene 3-angled, ovoid or narrowly ovoid, 3 mm. long, acute or acumi- 

 nate, shining, longer than the calyx. In sands of the seashore, Me. to Fla. Also 

 on the coast of Europe. July-Sept. 



24. Polygonum Rayi Babingt. RAY'S KNOTWEED. (I. F. f. 1341.) 

 Perennial or annual, glabrous, slightly glaucous ; stem 1-6 dm. long, prostrate, 

 usually much branched. Leaves ovate-lanceolate or oblong, 0.5-3 cm. long, acute 

 or obtusish at the apex, veined beneath, inconspicuously so above, shorter than the 

 internodes, inconspicuously jointed to the ocreae; ocreae becoming lacerate, silvery, 

 brown and glaucous at the base when old; flowers 2-4 together in the axils; 

 stamens 5 or 6; style short, 3-parted to the base; achene ovoid, 3-angled, 4-6 mm. 

 long, slightly granular but shining, much exceeding the calyx. In waste places, 

 N. B. and Prince Edward's I. to Br. Col., south along the Atlantic coast to Va. 

 Apparently naturalized from Europe. May-Sept. 



25. Polygonum erectum L. ERECT KNOTWEED. (I. F. f. 1342.) Annual, 

 glabrous; stem erect or ascending, 2-6 dm. high, terete, nearly simple or much 

 branched. Leaves oval, oblong or obovate, subsessile or short-petioled, 0.5-4 cm. 

 long, obtuse or subacute at the apex, conspicuously jointed to the ocreae; ocreae 

 oblique, funnelform, soon lacerate, silvery when young; flowers I or 2 together in the 

 axils; calyx greenish, enlarged in fruit; stamens 6 (sometimes 5); style very short, 

 3-parted to near the base; achene ovoid-pyramidal, 3-angled, 3 mm. long, reticu- 

 lated and dull, invested by the calyx, or the apex slightly protruding. In moist or 

 dry soil, Me. to Ont., the N. W. Terr., Tenn. and Ark. July-Sept. 



26. Polygonum exsertum Small. LONG-FRUITED KNOTWEED. (I. F. f. 

 1343.) Annual, glabrous, sometimes slightly glaucous; stem slender, brownish, 

 erect or nearly so, conspicuously striate, branched, 5-10 dm. tall. Leaves lanceo- 

 late, rarely oblanceolate, 1-4 cm. long, acute or cuspidate at the apex, acuminate 

 at the base, nearly sessile; ocreae soon lacerate, silvery, becoming brownish; calyx 

 greenish or white, 6-parted to near the base; stamens 5 or 6; style 3-cleft or 3- 

 parted, very short; achene 3-angled, narrowly pyramidal, 5-6 mm. long, more or 

 less constricted above the middle, chestnut-brown, smooth, shining, 2-3 times as 

 long as the calyx, at length twisted. N. W. Terr., south to 111., Mo. and Neb., 

 and on the Atlantic coast, in brackish marshes, from Me. to N. Y. Aug. -Oct. 



27. Polygonum ramoisssimum Michx. BUSHY KNOTWEED. (I. F. f. 1344.) 

 Annual, bright green or yellowish green, glabrous ; stem erect or ascending, 

 usually very much branched, slender, usually rigid, 1-12 dm. tall. Leaves lanceo- 

 late or linear-oblong, 0.5-4 cm. long, acuminate at both ends, persistent, conspicu- 

 ously jointed to the ocreae ; ocreae oblique, funnelform, few-nerved, becoming 

 deeply lacerate ; flowers several together in the axillary clusters ; calyx 5-6- 

 parted, greenish-white ; stamens 6 or fewer ; style very short, 3-parted to the 

 base ; achene 3-angled, acute, sometimes slightly protruding beyond the calyx, 

 nearly 3 mm. long, black, reticulated, dull. In saline soil, Minn, to the N. W. 

 Terr., N. Mex. and Cal., and on the Atlantic coast from Me. to N. J. July-Sept. 



Polygonum ramosfssimum prolfficum Small. Bushy, much branched ; stem nearly 

 erect, its internodes short, its nodes giving off 2 or more branches ; leaves narrower ; 

 flowers and achenes more numerous. Neb. and Kan., also on the coast of Me. 



28. Polygonum camporum Meisn. PRAIRIE KNOTWEED. (I. F. f. 1345.) 

 Annual or perennial, glabrous ; stem mostly erect, slightly striate, much branched, 

 sometimes slightly glaucous, 6-9 dm. tall. Leaves linear-lanceolate or oblong, 

 soon falling away, subsessile, rather obtuse at the apex, veined beneath, 0.5-2.5 

 cm. long ; ocreae funnelform, early lacerate and fugacious, dark brown ; flowers 

 several together in the axillary clusters ; pedicels short ; stamens 8 ; style short, 

 3-parted ; achene pyramidal-ovoid, 3-angled, black, nearly 3 mm. long, shining. 

 On prairies, Neb. to La., and N. Mex. Also in S. Am. July-Sept. 



