POLYGONACEAE (BUCKWHEAT FAMILY^ 361 



times lanceolate, obtuse or acutish, rounded or rarely subcordate at the base 

 (5-12 cm. long); peduncles glabrous: spike terminal, dense, ovoid or short- 

 cylindric (1.2-2.4 cm. long); Eowers bright rose-color, 3-6 mm. long; the 5 sta- 

 mens and 2-cleft style exserted. — Lakes and pools, e. Que. to N. J., and westw. ; 

 widely distributed and rather common. (Eurasia.) Var. terrestre Leers is 

 an erect terrestrial state with narrower acutish shortly petioled leaves scabrous 

 on the margin and often strigose-pubescent ; sheaths without herbaceous bol- 

 der. — Occasional with the typical form (also Eu.), and passing in Am. to Var. 

 Hartwrightii (Gray) Bissell with spreading foliaceous borders on the stipular 

 sheaths. (P. Har tier i ghtii Gra^y.) — An ambiguous plant, sometimes clearly a 

 mere terrestrial and mostly sterile state occurring on the same rootstock as the 

 typical form ; but elsewhere seemingly a normal and w^ell marked fertile variety. 



15. P. Muhlenbergii (Meisn.) Wats. Perennial, in muddy or dry places, 

 rarely in shallow water, decumbent or suberect, scabrous with short appressed 

 hairs; leaves lanceolate to ovate, narrowly acuminate (1-2 dm. long) ; peduncles 

 hispid and often glandular; spikes 3-10 cm. long, often in pairs; flowers and 

 fruit nearly as in the last. (P. emersum Britton.) — Que. and Me. to Fla., and 

 westw. — Exceedingly variable in foliage and pubescence ; aquatic states often 

 have essentially glabrous and cordate leaves, while in plants of drier situations 

 these are sometimes narrowly lanceolate, acute at base, and conspicuously ap- 

 pressed-pubescent on both surfaces. 



16. P. pennsylvanicum L. Annual; leaves lanceolate ; branches above and 

 especially the peduncles beset with stipitate glands; flowers uniform, bright 

 rose-color, in short erect spikes, often on exserted pedicels; stamens usually 8; 

 achene nearly orbicular, over 2 mm. broad, at least one surface concave. — Moist 

 soil, in open waste places, centr. Me., westw. andsouthw. — Neither the stamens 

 nor style conspicuously exserted. 



17. P. longistylum Small. Very like the preceding in habit and foliage; 

 flowers dimorphous, either the stamens or style conspicuously exserted ; achenes 

 orbicular, shining, both surfaces convex in the middle. — From s. 111. and Mo. to 

 w. Kan. (Meehan), and south w. 



18. P. Careyi Olney. Annual, erect, the stem (0.6-1.6 m. high) and pedun- 

 cles glandular-bristly; leaves narrowly lanceolate, attenuate to both ends, 

 roughish ; sheaths ciliate or sometimes margined ; spikes slender, loose and nod- 

 ding ; flowers purplish ; stamens mostly 5. — Swamps and recent clearings, Me. 

 to N. J., Ont., and Mich. 



19. P. Hydr6piper L. (Common Smartweed or Water Pepper.) Annual, 

 3-6 dm. high, smooth ; leaves narrowly lanceolate, vei^ acrid and peppery ; 

 spikes nodding, usually short or interrupted ; flowers mostly greenish ; stamens 

 6; style 2-3-parted ; achene dull, minutely striate. — Moist or wet grounds; 

 apparently introduced southeastw., but indigenous northw. and westw. (Eu.) 



20. P. acre HBK. (Water Smartweed.) Perennial, nearly smooth; 

 stems rooting at the decumbent base, 0.6-1.6 m. high; leaves lanceolate, atten- 

 uate, 7-12 cm. long, taper-pointed; spikes erect, rather dense, distinctly pedun- 

 cled ; flowers white or flesh-color; stamens 8; style mostly S-parted; achene 

 smooth and shining. (P. punctatum Ell., including var. robustius Small.) — 

 Wet places ; e. Mass., westw. andsouthw. (Trop. Am.) 



Var. leptostachyum Meisn. Annual; erect or slightly repent at the base, 

 3-6 dm. high ; leaves lanceolate, smaller, thinner, and lighter green than in the 

 type ; spikes elongated and very loosely flowered, not distinctly peduncled, the 

 widely scattered flowers commonly extending down to the upper leaf-axils. (P. 

 punctatum, var. Small.) — Moist ground, common ; sometimes well marked, at 

 other times passing imperceptibly into the typical form. 



21. P. orientXle L. (Prince's Feather.) Tall branching annual, soft- 

 hairy; leaves ovate or oblong, pointed, distinctly petioled; sheaths ciliate or 

 often with an abrupt spreading border ; flowers large, bright rose-color, in dense 

 cylindrical nodding spikes; stamens 7. — Sparingly escaped from gardens into 

 waste grounds. (Introd. from India.) 



22. P. PersicAria L. (Lady's Thumb.) Nearly smooth and glabrous (3-5 

 dm. high) ; sheaths more or less bristly-ciliate ; leaves lanceolate, pointed, 



