Hypoxis is a genus of flowering plants of the family Hypoxidaceae. The genus has an "almost cosmopolitan" distribution, occurring in Africa, the Americas, Asia, and Australia. Europe lacks native species. Most species are in the Southern Hemisphere, especially in southern Africa. Common names for the genus include star-grass, star lily, yellow stars, African potato, and stars. The genus is the largest of the Hypoxidaceae and has its centre of variation in South Africa, where it occurs in open undisturbed grasslands. The name Hypoxis was taken over by Linnaeus in 1759 from a name coined by Paul Reneaulme in 1611 for a superficially similar species of Gagea and meaning "a little sour", referring to the taste of that plant's leaves. Description These plants are perennial herbs with corms or rhizomes. Some have tubers. The aboveground herbage is a layered cluster of lance-shaped, linear, or hairlike leaves, sometimes sheathed together at the bases. The blades are usually at least slightly hairy. The flowers are borne on a short, stemlike scape in a raceme or umbel arrangement, or sometimes singly. The flower has six yellow tepals which may be hairy, especially on the undersides. The undersides may also be whitish or tinged green or red. Occasional flowers have 4 or 8 tepals. The fruit is a capsule with a few to many small, oily seeds. The seeds are needed to identify many species. Most have seeds less than 2 millimeters long, so microscopic examination is required. Uses Hypoxis plants have long played a role in traditional African medicine; H. hemerocallidea and H. colchicifolia are the best known species used to make medicine and teas. The genus is not only used in traditional medicine, it has become important also in pharmaceutical preparations. Archaeological evidence found in ashes in Border Cave, South Africa has revealed that early humans roasted the rhizomes of some of the more palatable species of Hypoxis as long as 170,000 years ago. Species Sources have estimated 90 or 100 to 150 species in the genus. , the World Checklist of Selected Plant Families recognized 90 species: Hypoxis abyssinica Hochst. Hypoxis acuminata Baker Hypoxis angustifolia Lam. Hypoxis argentea Harv. ex Baker Hypoxis arillacea R.J.F.Hend. Hypoxis aurea Lour. Hypoxis bampsiana Wiland Hypoxis camerooniana Baker Hypoxis canaliculata Baker Hypoxis catamarcensis Brackett Hypoxis colchicifolia Baker Hypoxis colliculata Sánchez-Ken Hypoxis costata Baker Hypoxis cuanzensis Welw. ex Baker Hypoxis curtissii Rose in J.K.Small – Curtiss' star-grass Hypoxis