gum-resinous

Gamboge is of a gum-resinous nature and clear yellow colour.

Field's Chromatography or Treatise on Colours and Pigments as Used by Artists George Field

All the plants appear to "form three different principles: the first, a watery acid matter; the second, a gum-resinous milky substance; and the third, an aromatic, oily secretion.

Scientific American Supplement, No. 829, November 21, 1891 Various