To vara 



POLYGONACEAE 



Polygonum 



enlarged in fr. ; styles persistent, 2-parted to the base, with recurved hooked tips: 

 achene lenticular, light brown, included in the perianth at maturity. One species, in 

 North America and eastern Asia. (Named for Simon a Tovar, Spanish physician of 

 the 16th century.) 



1. Tovara virginiana (L.) Raf. var. filiformis (Thunb.) Steward M't-^ (Chin Hsien 

 Ts'ao; Golden Thread Herb) (Ste. Po. 14). Erect herb, to lm.; fr. red, VIII-IX. 

 Eastern North America and eastern Asia; locally in An., Che., Hup., Ki., Ku. 

 Forest shade. Fig. 75. 



2. Polygonum Linn. Knotweed ig|| (Liao Shu) 



Herbs and shrubs with jointed stems: fls. in fascicles, from small sheaths called 

 ocreolae, on jointed pedicels; perianth 4-5- or rarely 6-parted, often petal-like, and 

 frequently persistent in fr.: achenes triangular or lenticular. About 200 species, 

 widely distributed; 100 in China. (Greek: polus, many; and gonu, knee; referring to 

 the nodes of the stem.) 



Key to the Species 



a. Fls. in axillary fascicles (Sect. Avicularia). 



Plants slender, glaucous, prostrate or ascending; lvs. linear to 



lanceolate, sessile or nearly so, mostly not over 5 mm. broad. 1. P. aviculare 

 Plants robust, erect, generally without glaucous bloom; lvs. 

 oblong to lanceolate, petiolate, margins often crisped, 5-15 



mm. broad la . P. aviculare 



var. vegctum 



aa. Fig. fascicles not axillary, 

 b. Inn. spiciform. 



c. Spikes cylindric to subfiliform, not capitate : ocreae not 

 tubular (Sect. Persicaria). 

 d. Ocreae with an herbaceous limb at the top, at least 



when young 2 



dd. Ocreae membranous. 



e. Ocreae eciliate, or sometimes very finely ciliate . 3 

 ee. Ocreae ciliate. 



f. Plant (except the fls.) scabrous with long 

 spreading hairs; stems and peduncles vis- 

 cous, glandular-hairy 4 . P. viscosum 



If. Plants glabrous or pubescent, sometimes scabrid 



with short appressed hairs, or the peduncles 



glandular-hairy. 



g. Infl. rather dense and continuously cylindric. 



Ocreae bearing coarse bristles 2/3 as long 



as the tube or longer; If. blades 



coriaceous. 



Spikes of the infl. rather densely fid.; 



perianth about 2 mm. long: achenes 



triangular : bristles mostly longer 



than the tube of the ocrea 5 



Spikes of the infl. rather laxly fid.: 

 perianth 2.5-6 mm. long: achenes 

 triangular or biconvex; bristles 

 usually shorter than the tube of 



P. orientate 



P. lapathifolium 



P. barbatum 



96 



