Euphorbia tuberosa bears green cyathia or false flowers clustered at the tips of fleshy, trailing peduncles (stalks) that grow from leaf axils and become from 12 mm to 37 mm long. Male cyathia clusters consist of two to five with sessile bracts, the female ones grow in an umbel with bracts at the base.
Each sessile (stalkless) cyathium has five spreading, yellow or green lobes, nearly triangular in shape with toothed margins, slightly outwardly curved or convex at the tips. Blooming happens from mid-autumn to early spring.
There is a curious story of another plant with scientific name E. tuberosa, indigenous to and described in Mexico; a later record than Linnaeus’s 1753 one of the South African plant. What it looks like is not known (iSpot; Manning and Goldblatt, 1996; Van Jaarsveld, et al, 2006; Bond and Goldblatt, 1984; http://llifle.com; www.bihrmann.com).