Hypoxis, a well-known genus of the family Hypoxidaceae, easily
recognizable by its bright yellow star-shaped flowers and strap-like
leaves, has a long history of medicinal use on the African continent
and is currently being used in South Africa in primary health care
as an immune booster for patients with HIV/AIDS.
geophytic herbs, Hypoxis plants overcome winter conditions
in the form of an underground rootstock called the corm. Corms are
hard, fleshy, mucilaginous and white or yellow-orange within. Sliced
corms, when exposed to the atmosphere, turn black with oxidation.
In spring, a new set of leaves grows from the apex of the corm.
In most species, leaves are arranged one above the other in three
rows that radiate outwards. In some species, leaf bases are enclosed
in a sheath, forming a false stem. Leaves range from linear to broadly
lance-shaped, are hairy in most species and die back over the winter
months. Flowering stems appear with the leaves after the first rains
in spring. They are unbranched, with 2-12 flowers per stalk. Flowers
are symmetrical with 6 tepals, rarely 4 or 8, are bright yellow,
giving the genus its common name "yellow stars". Only
in two taxa, H. membranacea and H. parvula var. albiflora
are the flowers white. The fruit is a capsule that splits across
its diameter to expose the small black seeds.
The name Hypoxis is coined from the Greek words hypo
meaning below and oxy referring to the pointed base of the
ovary or fruit.
Hypoxis has an estimate of 90 species world-wide and is almost
cosmopolitan in distribution, occurring in Africa, North and South
America, southeastern Asia and Australia. In Africa, the genus is
widespread south of the Sahara, with a concentration of about 41
species in southern Africa. Hypoxis is primarily a summer
rainfall genus with a large number of species in the eastern region
of South Africa. Seven species occur in the Cape winter rainfall
region, none of which are endemic to the region. Eleven species
of the 41 species are inland endemics, being restricted to altitudes
higher than 1 000 m whereas the remaining species extend from the
coast to the interior of southern Africa. Hypoxis is predominantly
a grassland genus, preferring full sunlight. A few species grow
on cliff faces or in forest shade.
flowers are short-lived and are pollinated by solitary and honey
bees. Pollen grains in Hypoxis are yellow and are visible
through the transparent pollen sacs of honey bees visiting flowers.
The fruiting capsule in Hypoxis, called a pyxis, splits along
its diameter and the upper portion of the capsule drops off, exposing
the black seeds. In a few species such as H. angustifolia,
the remaining lower portion of the capsule splits further longitudinally
to aid dispersal.
Economic and cultural value
In the genus, two species, H. hemerocallidea and H. colchicifolia
are most sought after for their use in African traditional remedies
as well as for preparation of herbal teas and tinctures. This places
demand on existing populations of these species in southern Africa
and as such, the species are under threat.
The rootstock of Hypoxis is used in various ways in South
Africa. H. hemerocallidea and H. colchicifolia rootstocks
were used by Zulu traditional healers for centuries in the treatment
of urinary infections, heart weakness, internal tumours and nervous
disorders. Corms of the latter species are used as an emetic against
fearful dreams. The Sotho people use Hypoxis as a charm against
lightning and storms. H. argentea has small white rootstocks,
and in times of famine the rootstocks are boiled or roasted by the
Sotho and Xhosa people as a source of food.
One species in particular, H. hemerocallidea (earlier name
H. rooperi) tagged by entrepreneurs as a 'wonder herb' and
'miracle cure', dominates the South African herbal enterprise. Corms
of H. hemerocallidea are being used to alleviate many immune
related ailments such as the common cold, flu, arthritis, tumours,
cancer and HIV/AIDS. The southern African public has resorted to
self-medication with all kinds of preparations from Hypoxis
corms, that have become available over the counter in health stores.
The value of the plant is in its content of a sterol called hypoxoside,
which once in the human gut, readily converts to rooperol, a biologically
active compound that balances the immune system. Preparations of
hypoxoside are being used in primary health care in South Africa
to boost the immunity in HIV/AIDS patients. The genus has great
potential as a source of new drugs with immuno-modulatory properties
and as such, is of economic value. However, clinical trials are
first needed to confirm the anti-inflammatory and immuno-modulatory
properties of Hypoxis.
The species described below were selected to give an idea of the
morphological diversity in Hypoxis, and to illustrate the
medicinally important species and those with potential for horticulture.
The first four species are common in grasslands in the summer rainfall
||Hypoxis hemerocallidea (previous name H. rooperii)
Best known member of the genus. Plants about 100 to 500 mm tall.
Leaves clearly 3-ranked, distinctly arching in the shape of
a sickle and are hairy all over. Widespread in the summer rainfall
region of South Africa, from coast to interior, extending nothwards
into Botswana where populations become fewer. Used for centuries
in African traditional medicine and recently recognized in the
alternative medicine trade as a 'wonder cure' for its immune-boosting
Very similar to H. hemerocallidea in appearance but differing
in its leaves being stiff, twisting with age, and with margins
white due to overlapping hairs. Widespread in southern Africa.
Used in the making of a floor polish for huts by local tribes
in the Estcourt area of KwaZulu-Natal. A very floriferous species
and has potential for horticulture. Occasionally hybridizes
with H. rigidula.
Second most popular species in the medicinal trade in South
Africa. Plants tall, 250-600 mm in height. Leaves are long and
wide and their bases wrap over to form a false stem, giving
the plant a tall, erect appearance. Leaves are tough and almost
hairless. Widespread from the coast to the interior of southern
Similar to H. colchicifolia in habit, differing in its
long but narrow leaves that are soft and bend backwards. Leaves
are hairy all over have strong fibres and are used to make rope
and hut trimmings. Two varieties are recognized by the density
of hairs on leaves: In H. rigidula subsp. rigidula,
the leaves are sparsely hairy with hairs lying mainly between
the ribs; in H. rigidula var. pilosissima, they
densely covered with hairs on both surfaces.
One of the few species used in the nursery trade as it is suitable
for cultivation due to its spreading rootstock. Plants are 70
to 300 mm tall and are clump-forming. Leaves are soft and of
a flaccid nature. Two varieties are recognized, based on width
of leaves. Common along shaded cliff faces in the Eastern Cape,
where it grows alongside and occasionally hybridizes with H.
A white-flowered, fragile species, widespread from coast to
interior in South Africa. Plants small, 40 to 100 mm tall. Corms
small, about 10 mm in diameter. Leaves membranous. Flowering
stalk with 1 to 3 flowers,which are Flowers white. Clump-forming
and easily spreading like H. angustifolia.
A mountain endemic occurring in South Africa, Swaziland and
Lesotho. Prefers moist, semi-shaded habitats among boulders.
Plants small, similar in habit to H. membranacea. Flowering
stalk with a single flower. Two varieties are recognized by
flower colour. Flowers in H. parvula var. parvula
are yellow and those of H. parvula var. albiflora
are white like in H. membranacea. Excellent for alpine
gardens. Produces occasional hybrids with Rhodohypoxis.
In the Garden
As the pictures show, most Hypoxis species are attractive
for development as garden ornamentals. Species suited for garden
beds are those with small corms and soft leaves like H. angustifolia
and H. membranacea which spread quickly through multiplication
of the rootstock to form a mass of plants. Hardy species with large
corms and strong leaves like H. hemerocallidea, H. colchicifolia,
H. obtusa and H. acuminata are fairly easy to maintain
once established in a garden. Seeds of Hypoxis germinate
better if sown soon after maturity.
- Gillmer, M. & Symmonds, R. 1999. Seed collection and germination:
Hypoxis hemerocallidea. Plantlife 21: 36, 37.
- Snijman, D.A. 2000. Hypoxidaceae. Cape plants. A conspectus
of the Cape flora of South Africa. Strelitzia 9: 108-110.
- Snijman, D.A. & Singh, Y. 2003. Hypoxidaceae. In G. Germishuizen
& N.L. Meyer, Plants of southern Africa: an annotated checklist.
Strelitzia 14: 1071-1074. National Botanical Institute,
- Singh, Y. 1999. Hypoxis: yellow stars of horticulture, folk
remedies and conventional medicine. Veld & Flora 85:
- Van Wyk, B-E. 2000. People's plants. Briza Publications,
Natal Herbarium, Durban