From Wiktionary, the free dictionary
acanaceous (not comparable)
- (very rare) Bearing prickles or thistles; prickly.
1921, William Dudley Pelley, The Fog: A Novel, page 276:But in addition, Johnathan, as the mocked parent, intended to see that the bed was as hard, knotty and acanaceous as the father knew how to make it.