Tuesday, 9 December 2014

Star flower Hypoxis hemerocallidea

Syn.         Hypoxis rooperii

Family :    Hypoxidaceae (Star lily family)

Zulu:         iNkomfe
English:    Star flower
German:  Afrikanische Kartoffel

Hypoxis hemerocallidea flower being visited by a honey bee

Distribution and habitat 
Hypoxis hemerocallidea occurs naturally in Botswana, Lesotho Swaziland and
South Africa where it is to be found in the eastern summer rainfall provinces of the Eastern Cape, Free State, KwaZulu-Natal, Mpumalanga, Gauteng and Limpopo. Hypoxis hemerocallidea occurs in a wide range of habitats, including sandy hills on the margins of dune forests, open grassland, rocky grassland, dry stony, grassy slopes, mountain slopes and plateaus and road verges.
Hypoxis hemerocallidea is a very attractive perennial with a large dark brown corm which is yellow on the inside when freshly cut turning black with time due to oxidation.

Hypoxis hemerocallidea has strap like leaves which grow up to 400 mm in lenght, neatly arranged one above the other in 3 ranks, broad, stiff and arching outwards with prominent ribs and tapering towards the tips. The lower surface of the leaves is densely hairy with white hairs. Leaves appear above ground in spring before the flowers.

The flowers are short-lived and close at midday. Flowers open sequentially from the base to the apex. Usually 1–3 flowers are open at the same time, thus encouraging cross-pollination.

The fruiting capsule is called a pyxis which splits along its diameter causing the upper portion of the capsule to drop off, exposing the black seeds that soon tip out.

The specific name hemerocallidea is derived from the Greek hemera (a day) and kallos (beauty), presumably referring to the flowers which are short-lived and resemble the day lily Hemerocallis.
Hypoxis hemerocallidea corm showing the yellow flesh on the inside

Hypoxis hemerocallidea is drought and fire-tolerant occurring widely in grassland where frequent fires are a feature of the ecological regime. 
Being deciduous Hypoxis hemerocallidea is dormant in winter the leaves having matured and died in the late summer as the ground gets drier and re-appear immediately after fire and begin to flower even in the middle of winter in frost free areas, often before the first summer rains. Fire clearly defines the beginning of the growing season.

The flowers of Hypoxis hemerocallidea are pollinated in particular by bees as well as other pollinators.

I have observed that it is browsed by indigenous domestic livestock in particular in the early spring after veld fires.
Uses and cultural aspects
iNkomfe (Hypoxis hemerocallidea) which is widely sold in many muthi markets, is probably the best known traditional medicinal plant in South Africa having been used for centuries, in recent years commercial products have become widely available in pharmacies.
Weak infusions and decoctions of the corm are used as a tonic and during convalescence, and against tuberculosis and cancer. It is also used for prostate hypertrophy, urinary tract infections, testicular tumours, as a laxative and to expel intestinal worms. Anxiety, palpitations, depression and rheumatoid arthritis are further ailments treated.

Hypoxis hemerocallidea has been very much in the limelight during the past two decades often being hailed as “miracle muthi” and “wonder potato”, today it is surrounded by controversy.
Hypoxoside a phytochemical has been isolated from Hypoxis hemerocallidea. This is an inactive compound which is converted to rooperol in the body, which has potent pharmacological properties relevant to cancer, inflammations and HIV.

Another compound which has been isolated from Hypoxis is sitosterol or phytosterol, which is an immuno-enhancer. Sitosterols are found in many green plants, and this is the main component of the commercial product ‘Moducare'.

A dye which is used to blacken floors is made from the leaves and corm.

The leaves are used to make rope.

Growing Hypoxis hemerocallidea
Hypoxis hemerocallidea is a hardy very attractive drought and frost tolerant deciduous geophyte that is extremely easy to grow which is an asset to any landscape or garden. It grows well in most soil types in full sun to partial shade where it flowers freely throughout summer. The yellow star-like flowers are eye-catching.
Propagating Hypoxis hemerocallidea
If one has a little patience Hypoxis hemerocallidea is easily propagated in large numbers from the vast numbers of small round shiny black seed that each plant produces. The seeds of Hypoxis hemerocallidea grow particularly well in raised seedbeds open to the ground for free drainage, however they have a dormancy period of about a year that needs to be taken into account, so collect the seed and store it in a cool dry place for planting in the next growing season. Making a fire over the seed once it has been planted as in most grassland species both grasses and forbs helps to break dormancy as well as stimulates the seed to germinate.

Use in the landscape
No indigenous or natural garden should be without masses of this very attractive local plant, use could also be made of Hypoxis hemerocallidea in formal landscape design where it can be either inter-planted with plants such as succulents that remain green during its winter dormancy or the beds which are planted to it can be attractively mulched with bark chips or other materials until it re-sprouts at the end of it´s winter rest. In the absence of fire watering will cause it to re-sprout earlier after a short dry rest period.
Hypoxis hemerocallidea has proved to be a very suitable plant for extensive green roof plantings in the summer rainfall areas because of its drought resistance and the fact that it is dormant during the dry winter months. 

Michael Hickman
Landscape Design and Rehabilitation Specialist

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