POLYGONACE^E. (BUCKWHEAT FAMILY.) 441 



to oblong or sometimes lanceolate, acutish, cuneate or cordate at base (2-5' 

 long) ; spike terminal, dense, ovate or oblong (-- V long) ; flowers bright rftse- 

 color (1^-3" long) ; the 5 stamens and 2-cleft style exserted. Widely distrib- 

 uted and rather common. (Eu., Asia.) 



10. P. Muhlenb^rgii, Watson. Perennial, in muddy or dry places, 

 Decumbent or suberect, scabrous with short appressed or glandular hairs ; leaves 

 thinner, rather broadly lanceolate, narrowly acuminate (4 - 7' long) ; spikes more 

 elongated (1-3' long), often in pairs; flowers and fruit nearly as in the last. 

 (P. amphibium, var. terrestre, Gray, Manual; not Leers.) N. Eng. to Fla., 

 westward across the continent. 



* * Sheaths and bracts bristly ciliate or the sheaths foliaceously margined. 

 *- Sepals not punctate; style 2-cleft; achene somewhat flattened. 



11. P. Hartwrightii, Gray. Perennial, very closely allied to n. 9, 

 growing usually in mud, the ascending stems rooting at base and very leafy, 

 more or less rough-hairy, at least on the sheaths and bracts, the former ciliate 

 and often with abruptly spreading foliaceous borders ; leaves rather narrow (2 - T 

 long), on very short petioles ; flowers and fruit as in n. 9. N. Eng. and N. Y., 

 to Minn., Iowa, and far westward. When growing in water the floating leaves 

 are thicker and glabrous. 



12. P. Careyi, Olney. Annual, erect, the stem (3-5 hig/^and pedun- 

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

 ish ; sheaths ciliate or sometimes margined ; spikes slender, loose and nodding ; 

 flowers purplish ; stamens mostly 5. Shady swamps, S. Maine and N. H. to 

 Penn. and Ont. 



P. ORIENTALE, L. (PRINCE'S FEATHER.) Tall branching annual, soft- 

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

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

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

 waste grounds. (Adv. from India.) 



P. PERSICARIA, L. (LADY'S THUMB.) Nearly smooth and glabrous (12- 

 18' high); sheaths more or less bristly-ciliate ; leaves lanceolate, pointed, 

 roughish, often marked with a dark triangular or lunar spot near the middle ; 

 spikes ovoid or oblong, dense, erect, on smooth (or at least not glandular) pedun- 

 cles ; stamens mostly 6 ; styles half 2 - 3-cleft ; achene gibbous-flattened or 

 sometimes triangular, smooth and shining. Waste and damp places, very 

 common. (Nat. from Eu.) 



*- - Sepals conspicuously dotted and leaves punctate (except n. 13), with acrid 

 juice; style mostly 3-parted,and achene triangular; sheaths bristle-fringed. 



13. P. hydropiperoid.es, Michx. (MiLD WATER-PEPPER.) Peren- 

 nial, not acrid; stem smooth (1-3 high), branching; the narrow sheath? 

 hairy; leaves narrowly lanceolate, sometimes oblong; spikes erect, slender. 

 sometimes filiform, often interrupted at base (1 - 2^' long) ; flowers small, flesh- 

 color or nearly white ; sepals not dotted ; stamens 8 ; achene sharply triangular, 

 smooth and shining. Wet places and in shallow water; common, especially 

 southward. 



14. P. Hydrdpiper, L. (COMMON SMARTWEED or WATER-PEPPER.) 

 Annual, 1-2 high, smooth ; leaves narrowly to linear-lanceolate ; spikes nod- 

 ding, usually short or interrupted ; flowers mostly greenish ; stamens 6 ; style 

 2-3-parted; achene dull, minutely striate. Moist or wet grounds; appa- 

 rently introduced eastward, but indigenous north and westward. (Eu.) 



