This species is characterized by an often robust tree habit, petiolate, medium-sized to robust (for Simira), ovate to broadly ovate or elliptic leaves that are truncate to shortly cordate at the base, pyramidal, multiflowered, pedunculate inflorescences, 5-merous flowers, lobed calyx limbs 0.8-1.5 mm long, funnelform corollas with tubes ca. 6 mm long and lobes 1.5-2 mm long, and woody capsules 3--4 cm in diameter. The specimens dry greenish brown or more often reddish purple. The leaves have small domatia, and are glabrous or usually densely puberulous on the principal veins. Corolla color has not been noted for this species. The capsules are quite woody.

Simira wurdackii is simlar to Simira fragrans, which is is found in the same region in southern Peru; Simira fragrans appears to be a distinct species without domatia and with tubular corollas with the tubes ca. 3 mm long rounded lobes ca. 1 mm long; the fruits of Simira fragrans are not yet confidently known, but this species seems to also have generally has narrower ovate leaf blades that rounded to truncate at the base. It is possible that Simira wurdackii is not distinct from Simira fragrans, but flower form and size do appear to be distinguish these and they are provisionally separated here. Simira wurdackii has been confused with Simira rubescens, which ranges into the same region, but differs in its subcapitate inflorescences, calyx limbs 2--5 mm long, tubular corollas with the tube 4-7 mm long, and capsules 2.5-3 cm in diameter with the walls rather thinly woody. Simira wurdackii is also similar to Simira mollis, with longer calyx limbs and the leaves densely velutinous-hirtellous throughout on the lower surface.