tached to the base of the perianth tube, orange-red, 5-lobed, the tips of lobes 

 free; ovary flattened; styles elongate, bifid to about or below the middle, included 

 or exserted; stigmas capitate; achene lenticular, 2.8-4 mm. long, beaked with 

 the persistent style base, blackish to deep reddish-brown, shiny, minutely punctate. 

 P. natans Eat., P. coccineum Muhl., Persicaria coccinea (Muhl.) Greene, P. 

 Muhlenbergii (Meisn.) Small. 



In ponds, rivers, streams, lakes, ditches, canals, marshes, swamps and mud in 

 wet meadows, in e. and n.w. Tex., Okla. (LeFIore, Comanche, Kay, Washita, 

 Cimarron and Alfalfa cos.), N. M. (Colfax, Dona Ana, Mora, Sierra, Sandoval, 

 Catron, Taos and Rio Arriba cos,) and Ariz. (Apache, Navajo and Coconino, s. 

 to Santa Clara and Pima cos.), June-Oct.; represented by 2 varieties in N. A. and 

 1 variety in Eurasia. 



Mitchell separates our two varieties as follows: 



1. Plants flowering while floating or recently stranded; inflorescence 1-4 or rarely 

 to 6 cm. long; aerial shoots decumbent to spreading, with chloro- 

 phyllous flared ocreae in the early season.. ..var. stipulaceum Colem. 



1. Plants flowering from aerial shoots on moist soil or strongly emergent from 

 the water; inflorescence 4-11 or rarely to 15 cm. long at maturity; 

 aerial shoots spreading to erect; ocreae with entire margins, becom- 

 ing membranous and soon shattering var. emersum Michx. 



16. Polygonum bicome Raf. Pink smartw^eed. 



Annual from taproot; stems erect, much-branched, cherry-red (at least at the 

 nodes), 1-20 dm. high; leaf blades lanceolate, punctate, glabrous except for a few 

 appressed hairs, 5-18 cm. long, 1-4 cm. wide; ocreae eciliate or occasionally with 

 cilia less than 1 mm. long, higher than wide; peduncles stipitate-glandular; ra- 

 cemes erect, numerous, terminal and lateral; calyx pinkish, 5-parted, 2.7-4.6 mm. 

 long; stamens 6 to 8. included or exserted (always of different length than the 

 styles); styles 2, included or exserted; achene lenticular, ridged or humped on at 

 least one face, dark-brown or black, lustrous, 2.5-3.5 mm. long and nearly as 

 wide. Polygonum longistyhim Small, Persicaria bicornis (Raf.) Nieuw. 



In and about water of ponds, lakes, sloughs and ditches, marshes, wet meadows 

 and in various disturbed habitats (often a first year invader) throughout Tex., 

 Okla. (McCurtain, LeFIore, Comanche, Logan, Pawnee, Rogers, Ottawa and 

 Nowata cos.), N.M. (San Miguel Co.) and Ariz. (Santa Cruz Co.), May-Jan.; 

 Neb. to Colo, and s. to Tex., N.M., Ariz., Calif, and Mex. 



The plants in southern Texas often have slightly fringed ocreolae (fringe absent 

 in north) and more pronounced ridges on the achene than their northern counter- 

 parts. 



17. Polygonum lapathifolium L. Willow smartweed. Fig. 410. 



Stout erect annual to 15 dm. tall; stems glabrous, conspicuously swollen above 

 nodes; leaves linear-lanceolate to oblong-lanceolate, 5-30 cm. long, 1-5 cm. wide, 

 acuminate, tapering to short petioles, the upper surface nearly glabrous, with 

 strigose scabrous veins and margins, the undersurface densely glandular-punctate 

 (occasionally densely white-tomentose beneath in aquatic forms) ; stipular sheaths 

 membranous, cylindric, 1-2 cm. high, glandular on margins, at length splitting 

 and becoming truncately fractured; inflorescence an elongate drooping spikelike 

 raceme, densely flowered, the peduncles glabrous to glandular; sheathing bracts 

 funnelform, obliquely tapered, 2 mm. long, glandular on margins; perianth pink 

 to white. 4- or 5-cleft to below middle, 2-2.9 mm. long, the tube lined with a 

 thin 5-lobed glandular disk, the veins of perianth segments dichotomously forked 

 and recurved at tips, becoming prominent in age; stamens 6, included, inserted 

 on tube and in sinuses; style 2-parted nearly to base; stigmas capitate; achene 



823 



