Flower of Eulophia petersii
Eulophia
petersii
The Zulu name
for this orchid is isaha
Eulophia
petersii is a terrestrial orchid belonging to plant family
Orchidaceae found growing in
thickets in hot dry arid, to very arid environments from
the
Arabian peninsular in the north down the eastern coast of Africa
southwards as
far as the Limpopo, Mpumalanga and KwaZulu-Natal provinces of South
Africa.
Eulophia
petersii is an unusual member of the orchid family in that it lives in
a harsh
environment where it has adapted to growing in very arid environments.
It is
among the
few orchid species to have
evolved a truly desert living
species.
It is often
found growing in acidic sandy soils or on rock outcroppings in
acid soil
derived from decaying granite.
Eulophia
petersii has many growth forms even within plant populations growing in
close proximity to one
another.
Below I have shown two specimens that are growing next to one another
in the same growing medium and growing conditions. One plant has medium
length leaves and
pseudobulbs
the other has extremely long leaves and long thin
pseudobulbs.
The leaves of Eulophia petersii are thick, fleshy and very fibrous and
have a sharp serrated edge that vary considerably in length from short
and broad to very long and narrow.
There are usually two to five leaves per
pseudobulb.
Eulophia petersii from the
Weenen area with medium length leaves
The pseudobulbs are green to yellowish with pronounced ribbing being
almost smooth when fully engorged with water and highly ribbed when
very dry the vary in length considerably.
Eulophia petersii from
KwaDenisa 29°20'2.86"S 30°52'13.40"E
north of Durban with extremely long leaves and long thin pseudobulbs
The form that grows in Yemen on the southern tip of the Arabian
peninsular is much smaller and more compact in habit.
The numerous flowers are widely spaced on a branched inflorescence that
can be up to over 2 meters in length. The flowers are green with
reddish brown markings with a wrinkled white lip with pink markings.
There is quite a bit of variability in the colouration of flowers
between plants. Often the sepals and petals are circinate, that is
spirally coiled with the tip innermost as in the photo above.
Eulophia petersii showing an
extensive, healthy root system supporting a healthy plant
Eulophia petersii plants consist of clusters of squat, fat green to
yellowish stems called pseudo bulbs connected by short rhizomes that
bear a small number of succulent, sharp-edged leaves. The plants are
evergreen and the leaves can persist for several years, but the actual
growth of the plants is highly seasonal.
New
pseudobulbs
and foliage are produced in spring and summer followed by tall racemes
of flowers which are produced in mid-summer.
In the winter, the plants go dormant and can withstand long periods
without water.
Traditional uses
Eulophia petersii is used as a love charm
Growing Eulophia petersii
Eulophia petersii are very easy and rewarding plants to grow inside and
outside provided one follows a few simple rules much the same as for
growing succulents. They grown well as pot plants indoors given
sufficient bright light. Eulophia petersii are very hardy and take very
little time to care for, to produce good results making them an idea
pot plant.
My own plants are grown in a mixture of coarse gravel derived from
decaying granite, crushed brick, and clean river sand to which I add a
small amount of well rotted leaf mould. They also do well in general
purpose cactus and succulent mixes.
I grow a number of my plants on a windowsill indoors where they get
plenty of sun. Grown outdoors the yellow orchid beetle Lema pectoralis
can be a major pest which can badly damage a plant in the blink of an
eyelid. To control the yellow orchid beetle on my plants growing
outside on my roof, at the beginning of the growing season I sprinkle
Efekto insecticide granules around the plants
I do not over pot my plants but I do ensure they have enough space to
develop a very good extensive root system this is essential for good
results.
Yellow orchid beetle Lema
pectoralis
In summer I only water my plants when the growing medium has completely
dried out for a week or so and I see that the pseudo bulbs have wilted
a little. I then completely soak the plants with water in a basin to
which I have added a little liquid fertilizer. Never add more
fertilizer per litre than the manufacturers recommendations, this has
produced very good results for me. At least once a year in the summer I
take the plants outdoors and soak them heavily with a hose pipe to
flush any accumulated salts out of the growing medium. This can also be
done indoors in a bathtub or basin.
In winter I keep my Eulophia petersii very dry, I only water them when
I see that the
pseudobulbs
have shrunk considerably and the two halves of the leaves have started
to fold together and then only enough to slightly wet the growing
medium, after a day or two I add a little more water until the
pseudobulbs have
regained not more than 50% of their full size. This ensures that the
plants develop a very large and healthy root system as can be see in
the accompanying photograph. I do not soak the plants in winter.
In the spring when new growths appear I slowly increase the amount of
water given until the new
pseudobulbs are
well developed
Eulophia petersii do not do at all if well if they over watered in
particular in winter and do not develop and maintain a good root
system. The easiest way to check if your plant is being over watered or
not is to gently tip it out of its growing container and to inspect the
roots. A healthy well cared for plant will have an abundance healthy
white roots with white tips while in active growth with no black marks
or rot on them.
Eulophia petersii can be grown outside in the garden if grown in well
drained soil and if they can be protected from mole rats and the yellow
orchid beetle. When grown outdoors they must be grown in a hot sunny
position or the new growths will tend to rot in the rainy season in
places such as Durban and the Natal coast.
Eulophia petersii has all the attributes to be an excellent green roof
plant, to confirm this I have tested Eulophia petersii for five years
under the conditions I experience at Mount Moreland with very good
results.
Eulophia petersii can easily be propagated by subdivision, which is
probably best done at the end of winter when the first new growth is
noticed, just be careful not to damage the new growth.
Eulophia petersii plants set seed if pollinated, but as with most other
orchids the seeds can mostly only successful be grown in flasks on a
special growing medium under sterile conditions. This b eing said they
do grow in soil under ideal conditions as in nature.
I have never tried growing Eulophia petersii seeds in soil as I have
successfully done with Eulophia speciosa, but with a little
experimenting under the correct conditions it is no doubt possible.
I feed my plants once per week at very low concentrations usually one
half or
less than the recommended application rate with a variety of feeds,
being EasyGro™ Flower and Fruit 3:1:6(46) hydroponic feed distributed
by Rolfes Agri, Seagro, Nitrosol, fulvic acid as well as with
both black as well as rooibos tea.