Perennial forb to 90cm tall. Leaves alternating up the stem or sometimes the lowermost opposite each other. The lower leaves usually hairy, the upper leaves usually hairless. Leaves 0.5-6cm long, 1-9mm wide, flat, becoming linear up the stem, margins flat or sometimes wavy; entire, sometimes with a few small teeth. Flowers bell-shaped, blue, with 5 lobes, in open groups at the tops of the stems.
Differs from Wahlenbergia gracilenta, Wahlenbergia gracilis and Wahlenbergia tumidifructa in that the free flower lobes are 6-13mm long, from Wahlenbergia communis in that the lower leaves are typically obovate and hairy, from Wahlenbergia fluminalis, Wahlenbergia littoricola, Wahlenbergia luteola, and Wahlenbergia graniticola in that the free lobes of the flower are less than twice as long as the tube, and from Wahlenbergia stricta ssp. alterna in that even the lowermost leaves are alternating up the stems.
Line drawings of flowers and fruiting bodies of seven species of Wahlenbergia in this key (but not Wahlenbergia graniticola, Wahlenbergia luteola, or Wahlenbergia stricta ssp. alterna) in Flora of South Australia 4th edition, Handbooks Committee on behalf of the South Australian Government (1986), Volume 3, page 1382
Photo of flowers. Photographer Glen Leiper, Tamborine, Qld