lenticular, minutely roughened, dark shining-brown or blackish, 2-2.5 mm. long. 

 Incl. var. incanum (Roth) K. Koch, Persicaria lapathifolia (L.) Small. 



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

 rather frequent throughout Tex., Okla., N.M. and Ariz., Apr.-Dec; introd. from 

 Eur. and now throughout N.A. 



18. Polygonum orientale L. Princess-feather. 



Annual from taproot; stems erect, branched, usually green, strigose, 4-30 dm. 

 high; leaf blades obovate, commonly truncate at base, strigose beneath, 6-22 cm. 

 long, 4-12 cm. wide: ocreae usually ciliate, about as wide as high; peduncles 

 tomentose; racemes numerous, erect; calyx 5-parted, pink to reddish-pink, epunc- 

 tate, 4-4.5 mm. long in fruit; stamens included; styles 2; achenes lenticular, 

 turgid, oval in cross section, black, lustrous, 3-3.5 mm. long, 1.8-2.6 mm. wide. 

 Persicaria orientalis (L.) Spach. 



A nat. of Eur. that is cult, in e. U. S. where it escapes frequently to wet 

 habitats, rare in e. Tex. and Okla. {Waterfall). 



19. Polygonum densiflorum Meisn. Fig. 411. 



Perennial; stems erect, branched, usually 7 mm. or more wide at base, usually 

 glabrous, 6-20 dm. high; leaf blades lanceolate, mostly glabrous, 5-25 cm. long, 

 2-5 cm. wide; ocreae ciliate or eciliate, brittle, longer than wide; peduncles 

 occasionally glandular or slightly pubescent; racemes numerous, long, often ap- 

 pearing compound, mostly erect; calyx whitish to whitish-pink, 5-parted, 2.3-3.2 

 mm. long; styles 2; achene lenticular, turgid, oval in cross section, lustrous, dark- 

 brown to black, 1.9-2.5 mm. long. Persicaria densiflora (Meisn.) Moldenke. 



Wet areas (often in water) along the Coastal Plain and inland to Okla. (Haskell 

 and Washington cos.), June-Nov.; infrequent but throughout e. U.S. and southw. 



20. Polygonum punctatum Ell. Perennial or water smartweed. Fig. 412. 

 Aquatic to amphibious perennial, rarely behaving as an annual; stems 3-10 dm. 



tall, erect or decumbent at base, rooting at nodes, simple or much-branched, green 

 above, reddish below, slightly swollen above nodes, glabrous or often glandular- 

 punctate; leaves lanceolate to ovate-lanceolate, acuminate, cuneate at base, 5-15 

 cm. long, 5-20 mm. wide, glabrous except on veins; petioles short; ocreae 

 cylindric, 9-17 mm. high, membranous, expanding with nodes, at length splitting, 

 scabrous, glandular-dotted, truncate above and bristly-ciliate; flowers in elongate 

 somewhat interrupted spikes, the pedicels glabrous, exserted; sheathing bract 

 narrowly funnelform, truncate, entire or rarely sparsely ciliate, glandular-dotted; 

 perianth green, less than 3 mm. long, 5-parted to below middle, conspicuously 

 glandular-punctate, green to greenish white, jointed to pedicels; stamens 6 to 8 

 inserted in sinuses or 1 to 3 inserted on lower half of tube, the green glands evident 

 in young fresh material but becoming obsolete in age; style 2- or 3-cleft; stigmas 

 capitate; achene lenticular or trigonous, 1.8-3 mm. long, microscopically roughened, 

 dark-brown or black and shining. Persicaria punctata (Ell.) Small. 



In shallow water in marshes, ponds and ditches, in mud of floodplain woods, 

 cienegas and wet fields, in e. Tex., throughout Okla., N.M. (Dona Ana, Grant 

 and Luna cos.) and Ariz. (Navajo and Coconino, s. to Cochise, Santa Cruz and 

 Pima COS.), year around; throughout N.A. to S.A. 



Often confused with P. Hydropiper which has dull achenes and nodding ra- 

 cemes. 



21. Polygonum Hydropiper L. Water smartweed. Fig. 413. 



Annual or perennial; stems ascending, glabrous or nearly so, green, 1-10 dm. 

 high; leaf blades lanceolate, punctate, 3-16 cm. long, 5-20 mm. wide; ocreae 

 2 to 4 times as long as wide, ciliate, the bristles usually less than 6 mm. long; 



826 



