Hypoxis

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Hypoxis
Temporal range: Pliocene - recent
Hypoxis angustifolia MS 3546.jpg
Hypoxis angustifolia
Scientific classification e
Kingdom: Plantae
Clade: Angiosperms
Clade: Monocots
Order: Asparagales
Family: Hypoxidaceae
Genus: Hypoxis
L.
Synonyms[1]
  • Upoda Adans.
  • Schinnongia Schrank.
  • Niobea Willd. ex Schult. & Schult.f.

Hypoxis is a genus of flowering plants belonging to the family Hypoxidaceae. The genus has an "almost cosmopolitan" distribution, occurring in Africa, the Americas, Asia, and Australia.[2] Europe lacks native species.[3] Most species are in the Southern Hemisphere, especially in southern Africa.[4] Common names for the genus include star-grass,[4] star lily, yellow stars, African potato,[2] and stars.[5] The genus is the largest of the Hypoxidaceae family[6][7] and has its centre of variation in South Africa,[6][8][9] where it occurs in open undisturbed grasslands.[8] 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.[10][11]

Description[edit]

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.[2][4][5]

The seeds are needed to identify many species. Most have seeds less than 2 millimeters long, so microscopic examination is required.[12]

Uses[edit]

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.[13]

Species[edit]

Sources have estimated 90[2][12] or 100[4] to 150[14] species in the genus. As of August 2013, the World Checklist of Selected Plant Families recognized 90 species:[15]

Gallery[edit]

References[edit]

  1. ^ Kew World Checklist of Selected Plant Families
  2. ^ a b c d Singh, Y. (Natal Herbarium, Durban). Hypoxis. plantzafrica: South African National Biodiversity Institute. 2004.
  3. ^ Hypoxis. Flora of China.
  4. ^ a b c d Hypoxis. Flora of North America.
  5. ^ a b Hypoxis. FloraBase. Western Australian Herbarium.
  6. ^ a b Singh, Y. (2007-07-01). "Hypoxis (Hypoxidaceae) in southern Africa: Taxonomic notes". South African Journal of Botany. 73 (3): 360–365. doi:10.1016/j.sajb.2007.02.001. 
  7. ^ Kocyan, Alexander; Snijman, Deirdre A.; Forest, Félix; Devey, Dion S.; Freudenstein, John V.; Wiland-Szymańska, Justyna; Chase, Mark W.; Rudall, Paula J. (2011-07-01). "Molecular phylogenetics of Hypoxidaceae – Evidence from plastid DNA data and inferences on morphology and biogeography". Molecular Phylogenetics and Evolution. 60 (1): 122–136. PMID 21459153. doi:10.1016/j.ympev.2011.02.021. 
  8. ^ a b Nordal, Inger; Laane, Morten M.; Holt, Ellen; Staubo, Inger (1985-02-01). "Taxonomic studies of the genus Hypoxis in East Africa". Nordic Journal of Botany. 5 (1): 15–30. ISSN 1756-1051. doi:10.1111/j.1756-1051.1985.tb02067.x. 
  9. ^ Wiland-Szymańska, Justyna. "The genus Hypoxis L. (Hypoxidaceae) in the East Tropical". Biodiversity: Research and Conservation. 14 (-1): 1–129. doi:10.2478/v10119-009-0011-5. 
  10. ^ Paul Reneaulme. Specimen Historiae Plantarum. 1611. page 92
  11. ^ Drewes and Khan (2004). "The African Potato (Hypoxis hemerocallidea): a chemical historical perspective". South African Journal of Science. 
  12. ^ a b Zona, S.; et al. (2009). "A seed atlas of Hypoxis from eastern North America" (PDF). J. Torrey Bot. Soc. 136 (1): 26–32. doi:10.3159/08-ra-086r.1. 
  13. ^ Betto, P.; Gabriele, R.; Galeffi, C. (1992-03-06). "Determination of the norlignan glucosides of Hypoxidaceae by high-performance liquid chromatography". Journal of Chromatography A. 594 (1): 131–135. doi:10.1016/0021-9673(92)80321-K. 
  14. ^ Genus Hypoxis. New South Wales Flora Online. National Herbarium. Royal Botanic Garden, Sydney.
  15. ^ Search for "Hypoxis", "World Checklist of Selected Plant Families". Royal Botanic Gardens, Kew. Retrieved 2013-08-19. 
  16. ^ Sánchez-Ken, J. G. (2010). "Hypoxis colliculata (Hypoxidaceae), a new species from Mexico and a key to the American species with black seeds" (PDF). Acta Bot. Mex. 92: 1–9. 

External links[edit]