The outside surfaces of Tetragonia nigrescens buds are sometimes pale green; red purple on other plants as here. These buds are also sunken in the centres of their four perianth segments, conspicuously ridged at the margins.
Glistening surface cells are more notable than hairs on these buds than on the hairy green T. nigrescens buds also shown in this Album.
The leaf petiole seen here is notably angular, rather than cylindrical (Manning, 2007; Le Roux, et al, 2005; iNaturalist).