198 POPULAR FIELD BOTANY. 
branches; the leaves, also, before they fall, have a red 
tinge. They are entire, slightly hairy beneath, and strongly 
nerved, opposite to each other on the stalk. Umbel of 
white flowers at the end of the branches. Woods and 
thickets, in chalk and limestone soils, produce this shrub. 
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TETRANDRIA. MOoONOGYNIA. 
MoNOCHLAMYDE®. URTICACE2. 
PARIETARIA. (Watt Prtirrory.) 
Generic Character. The calya divided into four. Filaments 
of the stamens, at first incurved or bent, then expanding with 
elastic force. Fruit with one seed, enclosed by the calya, which 
enlarges. Flower surrounded by an involucre. 
PARIETARIA OFFICINALIS. Common Pellitory of the Wall. 
A common plant on old walls and in waste places, flowering 
through the summer. It is not a conspicuous plant, the 
flowers being small, hairy, purplish, clustered amongst the 
leaves. Stem procumbent, sticky, and of a reddish hue. 
