Stem-leaves of Heterolepis aliena in picture grow scattered or irregularly spiralling up the stems, not really alternating. The stem is whitish, covered in velvety hairs, as are the lower leaf surfaces.

The almost linear to narrowly oblanceolate leaves have a few, short, thread-like teeth protruding along their margins and widely spaced, while the margins manage to roll under as well. The midribs are sunken on top, prominent and green below (Manning, 2007; iNaturalist).