Very similar to A. allenii but differs in having the glandular hairs confined to the inflorescence, the stems terete, and the leaves linear-lanceolate, more remotely toothed and usually ± glabrous. Also very like A. villicaulis but differs in having stems glabrous or ± so; stipelliform glands absent from the base of the leaf blade; leaf margin shallowly repand-dentate, and the female inflorescence laxer.