Hypoxis L.

First published in Syst. Nat., ed. 10. 2: 986 (1759)
This genus is accepted
The native range of this genus is Tropical & Subtropical to N. America.

Descriptions

Hypoxidaceae, I. Nordal & C. Zimudzi. Flora Zambesiaca 12:3. 2001

Morphology General Habit
Herbaceous geophytes; perennating organ a vertical rhizome surmounted by a ± dense coat of fibrous leaf remnants and ringed by stout contractile roots usually arranged in an equatorial zone on the rhizome.
Morphology Leaves
Leaves basal, sessile, linear to lanceolate, V-shaped in cross-section (conduplicate) or flat to ± terete, sometimes pseudopetiolate, sheathing at the base, pubescent along the abaxial midrib and margins, and often also on the lamina, sometimes forming a pseudostem (from the leaf sheaths and cataphylls), outermost leaves often reduced to cataphylls, new leaves produced successively from within older leaf bases the latter disintegrating into fibrous remnants; indumentum of 2-armed or 3–12-armed (stellate) hairs, white to brownish.
Morphology Reproductive morphology Inflorescences
Inflorescences usually produced continuously throughout the season; scapes simple or branched; flowers racemosely or corymbosely arranged, or flowers solitary; bracts hairy along the keel and margins.
Morphology Reproductive morphology Flowers Perianth
Perianth segments (tepals) free, acute to obtuse, persistent, yellow adaxially; outer tepals greenish and pubescent abaxially, inner tepals yellowish-green and pubescent only on the abaxial midrib.
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 6, uniseriate; filaments short; anthers latrorse, thecae fused or free at the apex.
Morphology Reproductive morphology Flowers Gynoecium Ovary
Ovary 3-locular; fruit a capsule with circumscissile or loculicidal dehiscence.
Morphology Reproductive morphology Seeds
Seeds with a distinct raphe, hilum and prominent micropyle; testa shiny black or dull brownish, smooth or variously papillose; the cuticle of the papillae smooth, or with 3–4 wing-like striae radiating from the papilla apex and often with fine irregular reticulate striae between.
[FZ]

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology Reproductive morphology Flowers
Flowers yellow; tepals persistent, the outer often somewhat narrower, longer and more acute than the inner ones
Morphology Reproductive morphology Flowers Androecium Stamens
Stamens 4–6; anthers dorsifixed
Morphology Reproductive morphology Fruits
Fruit a capsule or dehiscing by a lid.
Distribution
About 90 species, particularly in the Southern Hemisphere.
Morphology Leaves
Leaves in 3 rows, usually hairy
[FSOM]

Hypoxidaceae, J. Wiland-Szymańska, I. Nordal. Flora of Tropical East Africa. 2006

Vegetative Multiplication Corms
Corms most often surmounted by a ± dense coat of fibrous leaf remnants and ringed by stout contractile roots usually arranged in an equatorial zone
Morphology Leaves
Leaves basal, sessile, linear to lanceolate, V-shaped in cross-section (conduplicate) or flat to ± terete, (sometimes pseudopetiolate - not in our area), sheathing at the base, pubescent along the abaxial midrib and margins, and often also on the lamina, sometimes forming a pseudostem (from the leaf sheaths and cataphylls), outermost leaves often reduced to cataphylls, new leaves produced successively from within older leaf bases; indumentum of white, yellowish to brownish 2-armed (bifurcate) or 3–12-armed (tufted) hairs
Morphology Reproductive morphology Inflorescences
Inflorescences produced continuously throughout the season, or only at its beginning, on flattened scapes covered with tufted hairs, particularly in upper parts and on the rhachis
Morphology Reproductive morphology Flowers
Flowers, always supported by small hairy bracts, most often arranged in spicate to corymbose inflorescences, rarely only solitary; perianth segments (tepals) free, acute to obtuse, persistent, yellow adaxially (inside); outer tepals greenish and pubescent abaxially, inner tepals yellowish-green and pubescent only on the abaxial (outside) midrib; stamens equal in length or in the inner whorl shorter than in the outer, with short filaments; anthers latrorse, saggitate at the base, thecae fused or free at the apex
Morphology Reproductive morphology Fruits
Fruit a capsule with circumscissile (across carpels) or loculicidal (parallel to carpels) dehiscence
Morphology Reproductive morphology Seeds
Seeds with a distinct micropyle; testa shiny black or dull brownish, smooth or variously papillose; the cuticle of the papillae smooth, or with foldings, most often as wing-like striae radiating from the papilla apex with fine irregular reticulate striae between.
Figures
Fig 4, 1–9
Note
The genus includes a few diploid species with normal sexual reproduction (as H. angustifolia and H. filiformis) and several highly polyploid species that reproduce apomictically (asexual seed set, genetically equivalent to cloning). Plants with apomixis always create taxonomical problems, as the variation patterns are difficult to compare with those of sexual species, and species delimitation becomes complicated. Different morphological forms often occur in the same „population” as there is no gene exchange. Some authors have been splitters – and probably largely described clones (e.g. Nel 1914)–others have been lumpers (e.g. Nordal et al. 1985). Here we have tried to compromise. Generally, more field observations (particularly on underground organs) and microscopic observations (particularly on indumentum and seed surfaces) are needed. Adding to the difficulty in identifying taxa is the fact that the plants continue to produce new inflorescences while the leaves develop, thus completely altering the appearance through the season. Also the indumentum density changes through the season: in the same plant young leaves may appear densely pubescent, and old leaves may appear almost glabrous. When we refer to leaves in the key, this does not apply to the outer cataphylls, which might differ in indumentum and certainly in shape, but to well developed inner leaves in the rosette.
Distribution
Range: A genus of about 50 species, widespread in grassland and wooded grassland in Africa, America, Asia and Australia. Most of them appear to be fire tolerant, some even needing fire to flower.
[FTEA]

Sources

  • Flora Zambesiaca

    • Flora Zambesiaca
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Somalia

    • Flora of Somalia
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Flora of Tropical East Africa

    • Flora of Tropical East Africa
    • http://creativecommons.org/licenses/by-nc-sa/3.0
  • Herbarium Catalogue Specimens

    • 'The Herbarium Catalogue, Royal Botanic Gardens, Kew. Published on the Internet http://www.kew.org/herbcat [accessed on Day Month Year]'. Please enter the date on which you consulted the system.
  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0
  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2025. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0