A red or yellow resin obtained from the base of Australian grass trees of the Xanthorrhoea family. Red accroides, or red gum, comes primarily from X. australis in southeastern Australia. Yellow accroides, or black boy gum, is relatively scarce and comes from the tree X. preissii of Western Australia. The resins are chemically similar to balsams and contain some cinnamic acid. They produce hard, insoluble films. Treatment with Sulfuric acid produces a lightfast brown-black dye (Brady 1971). Accroides is used for varnishes, metal lacquers, surface finishes for leather and paper, substitute for rosin, sealing waxes, and inks.
Synonyms and Related Terms
acaroid; gum accroides; résine acaroïde (Fr.); goma de acroides (Esp.); yacca gum; black boy resin; black boy gum; red acaroid; red gum; grass tree gum; Botany Bay gum; xanthorrea resin; xanthorrhoea gum cement
Physical and Chemical Properties
Soluble in ethanol and aniline. Slightly soluble in chlorinated compounds.
Resources and Citations
- G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 7
- Ralph Mayer, A Dictionary of Art Terms and Techniques, Harper and Row Publishers, New York, 1969 (also 1945 printing)
- Art and Architecture Thesaurus Online, http://www.getty.edu/research/tools/vocabulary/aat/, J. Paul Getty Trust, Los Angeles, 2000