160 SIXTEENTH REPORT. 



for hedges, but not escaping so far as noticed. Apparently not a success as 

 a hedge plant in this locality. 



Moms alba L. White Mulberry. — Occasionally planted for ornament, but 

 not spreading. 



Urtica gracilis Ait. Slender Nettle. — Very common in moist ground, 

 damp open Avoods, and along fence rows. 



Laportea canadensis (L.) Gaud. Wood Nettle. — Common in rich woods 

 and thickets. 



Pilea pumila (L.) Gray. Richweed. Clearweed. — Frequent in rich open 

 woods and thickets. 



Boehmeria cylindrica (L.) Sw. False Nettle. — Common in moist or shady 

 ground. Abundant on marshy ground near Port Franks. 



Santalaceae. Sandalwood Family. 



Comandra richardsiana Fernald. — Bastard Toad-flax. — Very common in 

 dry and sandy ground. Formerly included in C. umbellata (L.) Nutt. 



Aristolochiaceae. Birthwort Family. 



Asarum canadense L. Wild Ginger. — Frequent in clamp rich woods and 

 thickets. 



Polygonaceae. Buckwheat Family. 



Rumex britannica L. Great W^ater Dock. — Frequent in swamps and wet 

 marshy places. 



Rumex crispus L. Yellow Dock. — Very common in cultivated and waste 

 grounds. A miserable weed in hay fields, grain fields, and pastures. 



Rumex altissimus Wood. Pale Dock. — On Walpole Island near an In- 

 dian dwelling. Apparently rare, 



Rumex verticillatus L. Swamp Dock. ^Frequent in swamps and along 

 low l)anks of streams. 



Rumex obtusifolius L. Bitter Dock. — Common on roadsides, aiid in waste 

 places. A l)ad weed in cultivated grounds and pastures. 



Rumex acetosella L. Field Sorrel. Sheep Sorrel. — Very common espe- 

 cially as a weed in old fields. 



Polygonum aviculare L. Knot-grass. Door-weed. — Common in j-ards, 

 lawns, fields and waste places. 



Polygonum aviculare littorale (Link.) Koch. Shore Knotweed. — Frequent 

 in hard clay ground. Often covering large ant-hills on the delta islands of 

 St. Clair River. 



Polygonum aviculare vegetum Ledeb. Larger Knotweed. Near a grain 

 elevator at Point Edward. Apparently infrequent. 



• Polygonum erectum L. Erect Knotweed. — Common on roadsides, in 

 cultivated grounds and waste places. 



Polygonum tenue Michx. Slender Knotweed. — Noticed in poor and 

 sandy ground near Blaekwcll Station. T. C. Wheatley. 



Polygonum lapathifolium L. Slender Pink Persicaria. — Frequent in damp 

 ground. Often a garden weed. 



Polygonum amphibium L. Water Persicaria. — Frequent in marshy 

 places, on i)orders of ])onds, lakes, and slow streams. 



Polygonum amphibium hartwrightii Gray. Hartwright's Persicaria. — 

 Frequent in damp marshy places. Noticed in particular near a large pond 

 north of Sarnia. 



