Definition of "foliaceous"

I have one specimen, in which the primary crystals are siliceous, the secondary thin foliaceous crystals of deep red but transparent iron-ore, forming elegant figures, that have the form of roses.

1795, James Hutton, Theory of the Earth, Volume 1 (of 4)‎

The bitter principle contained in the root, wood and bark was discovered by Blunse who named it samaderin; it is a white, crystalline, foliaceous substance, more soluble in water than in alcohol, fusible.

1901, T. H. Pardo de Tavera, The Medicinal Plants of the Philippines‎