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.
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
18.04.14
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