4.2. H. rivulicola Goldblatt in Jl. S. Afr. Bot. 50: 60 (1984)

Although first collected in the 1920s and early 1930s around Nieuwoudtville on the Bokkeveld Escarpment, H. rivulicola was described only in 1984 (Goldblatt, 1984) after additional populations were found near Calvinia at the Akkerendam Nature Reserve, ± 980 m. Exploration of the western end of the Hantamsberg in 2014 on the Farm Tierkloof resulted in the discovery of an additional population of the species on Sandkop. Plants were common along streams on shale, growing in moss pads, and at the shallow edges of marshes on a dolerite sill at elevations of ±1 380 m. The extended population consisted of over 200 plants. The Tierkloof populations extend the altitudinal range of H. rivulicola significantly and indicate that the species is more common than previously known. Leaves of these plants were rectangular with the margins almost square to oblong-elliptic in cross section and lightly striate. Elsewhere the leaves have been described as elliptic with rounded margins and shallowly grooved.

South Africa. NORTHERN CAPE. 3119 (Calvinia): Hantamsberg, Farm Tierkloof, near the top of Sandkop, along shallow stream in moss pads, 1 380 m, (− BC), 27 Sept. 2014, P. Goldblatt & L.J. Porter 14034 (MO, NBG) .