Polygonum 



POLYGONACE.-E 



109 



2. POLYGONUM L. 



Herbs, sometimes shrubby at base. Leaves alternate. Flowers 

 clustered on spike-like racemes, sometimes panicled [or capitate 

 in corymbs]. Perianth deeply 5-lobed, coloured. Stamens 8-6, 

 inserted on the perianth. Styles 2 or 3 united below ; stigmas 

 capitate entire. Nut small. Embryo excentric in endosperm ; 

 cotyledons narrow. 



Species about 150, widely dispersed through the whole world. 



Fig. 33. Polygonum punctatum Ell. 



A, Leaf and flower-spikes. E, Nut. 



B, Portion of flower-spike. F, Du. in transverse section ; e, endo- 



C, Perianth cut open. sperm ; c, embryo. 



D, Seamen. 



1. Flower-clusters in spike-like racemes. 

 Stipules setose-ciliate. 



Glandular-punctate on calyx and stipules. 



Stipules puberulous 1. P. ]}unctatum. 



Not glandular. Stipules hispid 2. P. acuminatiivi. 



Stipules not setose-ciliate. 



Glandular-hispidulous on young branches and 

 peduncles. Leaves linear or linear-lanceo- 

 late 3. P. mcxicanum. 



Glabrous. Leaves lanceolate 4. P. glabrum. 



[ 2. Flowers capitate in corymbs P. chincnse.] 



