This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
A distinct Caucasian plant, 3-5 ft. high, with broad deeply ribbed leaves and erect trusses of white and greenish flowers. V. nigrum and V. viride (Helonias viridis) have purplish and greenish flowers respectively. All kinds have poisonous rootstocks, from which the Hellebore powder of commerce is prepared. (See Vol. I, p. 215.) The plants like a rich, loamy soil, with a little peat or leaf mould, and are increased by seeds and division.