Australian logrunner one of only three species within the single Orthonyx genus; the other two are the chowcilla ("Orthonyx spaldingii") from northern Queensland and the New Guinean logrunner ("Orthonyx novaeguineae") from Papua New Guinea. Logrunners as a group are characterised within their group by their distinctive tail feathers where the rachis (or central shafts) of the tail feathers protrude and are stiffened. The broad tail of the bird is less than four inches (10 cm) in length and the strong protruding rachis at the ends of the tail feathers are almost void of the usual barbs, giving the feather the appearance of
Acorus calamus asexually. The tetraploid variety is usually known as "Acorus calamus var. angustatus" Besser. A number of synonyms are known, but a number are contested as to which variety they belong. It is morphologically diverse, with some forms having very broad and some narrow leaves. It is furthermore also cytotypically diverse, with an array of different karyotypes. "A. calamus" has been an item of trade in many cultures for thousands of years. It has been used medicinally for a wide variety of ailments, and its aroma makes calamus essential oil valued in the perfume industry. The essence from the rhizome is