This section is from the book "Handbook Of Hardy Trees, Shrubs, And Herbaceous Plants", by W. Botting Hemsley. Also available from Amazon: Handbook of hardy trees, shrubs, and herbaceous plants.
Inhabiting swampy places.
An inflorescence, having the flower- stalks radiating from one point. An umbel is either simple or compound.
Growing in shady places.
Destitute of spines or prickles.
Having a wavy margin.