This is the yellow flowering form of Veltheimia bracteata, also called the sand lily or in Afrikaans sand-ui (sand onion). The flowers have a faint greenish tinge. The shiny aspect of the leaves can be observed in this specimen, growing in nearly full shade in a Western Cape garden. The plant is winter growing, the leaves dying back to some extent depending on conditions. The habitat is Eastern Cape forests and coastal scrub.
There are only two species of Veltheimia left after the last revision; the other one being V. capensis that grows in the drier western parts of South Africa. It has narrower, more erect and bluish leaves, while the flowers are similar to those of V. bracteata (www.plantzafrica.com; www.pacificbulbsociety.org).