Yellow Ground Orchid Eulophia speciosa

Yellow Ground Orchid 

Eulophia speciosa 

IsiZulu: Umabelejongosi Ompofu; Umlunge Omhlophe

Eulophia speciosa growing and flowering very well under harsh conditions on my roof at Mount Moreland

Description

Eulophia speciosa is aptly named ‘speciosa’ – Latin for ‘beautiful, handsome and showy’.

Eulophia speciosa is a terrestrial perennial plant producing 3 - 6 leaves 15 - 65cm long on a central flowering stem up to 150cm tall. The stem grows out of an underground string of pseudo bulbs which are 4 - 6 long and up to 4cm wide

Distribution

Eulophia speciosa is a species of terrestrial orchid has a wide distribution range being from Western Saudi Arabia, Yemen, Ethiopia, most countries of the central and eastern parts of Africa, from Angola and the Democratic Republic of the Congo, northern Botswana and north eastern Namibia to Swaziland, Mozambique and South Africa where it occurs from the Limpopo, Mpumalanga, southwards to KwaZulu-Natal through the Eastern Cape to the Western Cape as far as the George-Knysna area.

Habitat

The plants normally grow in savannah grassland, bush land and wooded grassland, and have also been recorded from marshy coastal grassland and montane grassland. They are found in grassland from near sea level often exposed to salt spray to 1 700 m in southern Africa, and up to 2 000 m in East Africa. In South Africa the plants usually grow in colonies of up to 50 plants generally in sandy soils but are also found growing in clay soils. This wide-ranging species is obviously rather adaptable, and can therefore thrive under different conditions in cultivation although it is not likely to survive very severe frost.

Ecology

The flowers of this species are deceptive and offer no nectar or other reward to the pollinating insect. Pollinators are large carpenter bees (Xylocopa sp.)

I have seen these Giant Carpenter Bees Xylocopa flavorufa pollinating my plants at Mount Moreland

Cultural uses

Root infusions of Eulophia speciosa are prepared as emetics for both humans and animals. In traditional medicine, emetics are widely used to facilitate the removal of what is thought to be the cause of the ailment.

Eulophia speciosa plants are also used as a protective charm against storms.

It is reported that Eulophia speciosa bulbs are a favoured food of local people within the plants native range, and are extensively harvested from the wild for local use.

Often eaten raw, sometimes with a little salt, as soon as it is harvested, the bulb is also mashed up and mixed with other raw food plants such as Talinum spp., Dipcadi glaucum and Kedrostis foetidissima. The pounded roots are also added to soups and sauces

Growing Eulophia speciosa

I have grown Eulophia speciosa for about the last 50 years and have found them easy to grow keep an eye on them but be aware that too much care can kill them.

Eulophia speciosa is often a pioneer plant generally on poor sandy soils near the coast in its natural habitat which matures to flowering size in between two and three years depending on conditions.

Over the last few years I have trialled these plants as green roof plants with great success under conditions where they only receive natural rainfall mostly in the summer months. I trials they have proved to be most suitable for growing on extensive green roofs that receive little maintenance and supplemental watering.

Eulophia speciosa are best grown in pots of large growing containers where they are safe from attack by mole rats or planted out in garden beds where they will need to be carefully monitored for attack by mole rats. If mole rats find them then they will probably need to be lifted and put into containers because once found the mole rats will not leave until they have eaten the last bulb. Eulophia speciosa needs to grow in full sun for much of the day to flower well and to remain healthy.

In the growing period, the substrate should be fairly moist, but a constantly wet soil must be avoided. Plants are best transplanted and divided in the dormant season, and should be potted. Eulophia speciosa are to some degree dependent on their mycorrhiza fungus species but it is certainly not necessary to inoculate the potting medium with mycorrhiza fungus because the roots of the plants will already have their populations living within them.

Suitable drainage must be provided to prevent water logging in times of prolonged heavy rain to avoid rotting of the roots. Regular watering should not be needed, only during periods of drought will they need additional watering. An annual topdressing with well rotted leaf mould or bark compost mixed with a little slow release fertiliser and a little lime is essential for healthy sustained growth of the plants. Occasional feeding with a liquid fertilizer during the growing season will do no harm but do not overdo it or the plants will become weak and will be far more susceptible to bacterial rot and fungus attack. 

Although Eulophia speciosa has great hybridizing potential I strongly discourage doing so because of the possible contamination of wild specimens.

The simplest way to propagate Eulophia speciosa is by division of dormant back bulbs which are removed leaving three healthy pseudo bulbs for continued growth.

To produce large numbers of plants in a short period of time propagation will need to be done by means of planting seed. Practically every flower will produce viable seed pods if hand pollinated regardless if they are self or cross pollinated, but do not overdo or the plants will become weakened by the effort of producing too larger amount of seed, 5 seed pods per plant should be fine.

The seed can then be grown in vitro in a suitable growing structure with ease if suitable equipment is at hand, otherwise you can simply do what I have done for years and that is to simply plant the seed in prepared seed beds which I have done over the years with a good degree of success. I also find many seedlings that just pop up in the garden from time to time from seed that my plants produce.

Young healthy plants flower about 2-4 years after sowing.

Some of many Eulophia speciosa plants undergoing suitability trails as green roof plants on one of my roofs at Mount Moreland

Pests and diseases

A number of pests feed on Eulophia speciosa such as leaf miners and the yellow orchid beetle Lema pectoralis which do a large amount of damage to the plants if not dealt with promptly.

Yellow orchid beetle Lema pectoralis

Bacterial rot due to over watering, watering during the dormant season, crowding and insufficient air circulation can be a problem. If planted out in large numbers in garden beds, the plants most probably will eventually be eaten by mole rats that feed on the pseudo bulbs. If the Mole rats find them then they will have to be lifted to be placed in containers or they will eat every last one.

Landscape uses

Eulophia speciosa is a very showy and desirable plant to include in any landscape design or garden.

Eulophia speciosa makes a good container plant for the patio and brings colour and life to the green roof be it big or small.

General Information

Eulophia speciosa is the floral emblem of the South African Orchid Council http://www.saoc.co.za/

Michael Hickman

Landscape Design Specialist

www.ecoman.co.za

michael@ecoman.co.za

18.04.14

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