The much-branched stems of Lacomucinaea lineata, previously Thesium lineatum grow densely together. They are pale grey-green to blue-green and hairless, sometimes longitudinally channelled and spine-tipped.

Small, fleshy leaves seen on young stems are narrowly elliptic with acutely angled, tapering tips. They mostly drop off early, but some plants may carry many of them (Vlok and Schutte-Vlok, 2010; iSpot; JSTOR).