peduncles usually glabrous, glandular; racemes numerous, moniliform, commonly 

 nodding or drooping; calyx yellow-glandular, green or greenish-white (pink at 

 tip on young buds), 2.5-4.1 mm. long in fruit; stamens included; styles usually 

 3; achenes dark-brown or black, dull, minutely pitted, mostly trigonous, 2-3.3 mm. 

 long. Persicaria Hydropiper (L.) Opiz. 



Wet meadows, in water of streams and pasturelands, in Okla. (Delaware Co.) 

 and mostly in e. Tex., June-Dec; throughout N.A. and also parts of Euras. 



Similar to and often confused with P. punctatum. 



22. Polygonum Persicaria L. Lady's thumb, moco de guajolote. Fig. 414. 



Erect or decumbent amphibious annual, rooting at nodes, often in large clumps; 

 stems 2-9 dm. tall, green or marked with red, diffusely branched or occasionally 

 simple and erect, glabrous and at length swollen at nodes; leaves lanceolate to 

 linear-lanceolate, 3-15 cm. long, 5-18 mm. wide, acuminate, tapering to the 

 short petiole, sparsely strigose to nearly glabrous, sometimes glandular-dotted; 

 stipular sheaths extending 1-2 cm. beyond junction of petiole, strigose, the apex 

 truncate and bristly-ciliate; inflorescence of a few short erect stout densely flowered 

 spikes, 8-25 mm. long, these on tips of terminal and lateral branches; sheathing 

 bracts membranous, ciliate; perianth petaloid, 2.2-3.2 mm. long, glandless, deep- 

 dull-rose to white, 5-parted to near middle, the base lined with a 5-lobed yellowish 

 green glandular disk; stamens 6, some inserted in the sinuses and 1 to 3 between 

 the glands of the disk; style short, 2- or 3-branched; stigmas capitate; achene 

 lenticular to trigonous, microscopically pitted, dark-brown or black and shining, 

 2-2.7 mm. long. Persicaria vulgaris Webb. & Moq. 



In marshes, boggy areas, in shallow water and on edge of ponds, lakes and 

 streams, often in disturbed areas, throughout Tex., Okla. (Alfalfa, Murray and 

 Adair cos.), N. M. (widespread) and Ariz. (Navajo, Coconino, Yavapai, Cochise 

 and Mohave cos.), June-Dec; introd. from Eur. and now throughout N. A. 



Similar to and often confused with P. hydropiperoides. 



23. Polygonum hydropiperoides Michx. Waterpepper. 



Herbaceous annual or perennial, subglabrous to strongly pubescent; stem to 

 2 m. long, mostly much less, usually somewhat decumbent below and tending to 

 root freely at the nodes; leaves numerous, only slightly reduced upward, short- 

 petiolate or the upper ones subsessile, narrowly to broadly lanceolate or oblong- 

 lanceolate, 5-24 cm. long, to 6 cm. wide, acute to acuminate, glabrous to strongly 

 strigose, acute at base; ocreae 1-2 cm. long, ciliate, strigose and bristly-ciliate; 

 inflorescence of 2 to numerous slender-tapering often interrupted spikelike ra- 

 cemes mostly over 4 cm. long, on a strigose to glabrous peduncle; perianth greenish 

 to white or pinkish, 2.5-3 mm. long, glabrous externally on the exposed area, 

 without glands, 5-lobed for slightly more than half the length with the oblong 

 segments subequal and the inner ones sometimes slightly glandular; stamens 8, 

 included; style 3, connate about half their length, about 0.5 mm. long; achene 

 dark-brown to black, smooth and shining, triquetrous (the faces flat), 1.5-3 mm. 

 long. 



In marshes, wet meadows, in and on edge of water of streams, ponds and lakes, 

 sometimes forming mats in streams, occurring as one or more variants throughout 

 Tex., Okla., N.M. and Ariz., Apr.-Nov.; Que. to B.C., s. to S.A. 



1. Hairs of the ocreae long and spreading, enlarged at base, not adnate; mostly 



along the Gulf Coast, extending into southeastern Oklahoma 



var. setaceum. 



1. Hairs of the ocreae erect and appressed, adnate at base (2) 



830 



