Rikus van Veldhuisen. Introduction
Euphorbia meloformis is probably the best represented Euphorbia
in our collections. And so there are not many of the about 500
succulent species of Euphorbia's about which was written more
than about Euphorbia meloformis. The reason that your writer still
picks up his pen is the fact quite some recent knowledge can be
added to the already existing information.
Euphorbia meloformis is a very 'ancient' species, because she
was already described in 1789, by William Aiton (gardener of king
George III) in the second part of the first edition of the Hortus
Kewensis. He called her the 'melon-shaped spurge' and stated that
she was brought to England in 1774 by Francis Masson. After this
many famous botanists quite deservedly took an interest in this
species according to numerous publications about E. meloformis
By the way, in the 'Euphorbia-bible' White, Dyer & Sloane
talk about an 'apple-shape' instead of a 'melon-shape', which
is much more appropriate in my opinion.
The typelocality of Euphorbia meloformis is near the Zwartkops
River, north-west of Port Elizabeth. The localities around Port
Elizabeth, in the vicinity of the ocean, form the most western
distribution-area of Euphorbia meloformis.
Over a hundred km to the east there's a second distribution-area
in the neighbouthood of Grahamstown. The plants in this area differ
from one population to another, but also from one plant to another.
This has caused much confusion. And on top of this there is a
very closely related 'species' growing nearby, Euphorbia valida,
at several locations a bit further away from the ocean, to the
north and west of the two mentiond areas.
And again at more than a 100 km to the east of Grahamstown, a
bit north of Peddie, plants were found in 1975 which look very
similar to Euphorbia meloformis. They deserve though a separate
These three geografically clearly separated distribution-areas
form the base for this article. Therefore I will introduce them
a bit more intensive by describing the characteristic features
of the plants and by some accompanying pictures.
Plants, on which the original description in 1789 is based, originate
from the neighbourhood of Port Elizabeth.
Some striking characteristic features of Euphorbia meloformis
from around Port Elizabeth are:
- plants stay rahter small, they grow to max. 12 cm in diameter
- they have rounded ribs with red-brown cross-bands
- the flowerstalks of the male plants remain longer on the plant
than those of the female plants
- they have practically always 8 ribs and branch only seldom
- the seedlings are already from the start almost sphearical and
their little leaves dry quickly.
Having said this, it is however possible to find near Grahamstown
an individual plant, which does match the above given features
quite well. And also one can find an indivudual plant near Port
Elizabeth, whhich looks like the most commen form occurring near
Grahamstown. Only the frequency of certain characteristic features
differs in the populations from these areas. Because of this the
most common appearance of a population at a certain locality is
indeed different to th most common appearance of a population
at another locality.
It is not a surprise
that, after studying the many appearances of E. meloformis and
E. valida, Dr. Marloth came to the conclusion that the plants
from Port Elizabeth belonged to the variety pomiformis. He also
ranked all the other plants, including Euphorbia valida, among
the variable species Euphorbia meloformis. Taxonomically seen
this can not be right. The type-form can never be degraded to
a variety. Though the thougt behind this approach is quite understandable.
Unfortunately all Port Elizabeth-localities are being threatened
by town development and her survival in nature is thus most uncertain.
Plants from these locations also rarely show up in collections
which is quite a shame because they are considered to be the most
Haworthia cooperi var. pilifera (J&R176) grows at this
Corpuscularia (former Delosperma) lehmannii
grows together with E. meloformis
North and north-west
of Grahamstown, just about 100 kilometers east of Port Elizabeth,
Euphorbia meloformis is much more common. Most of the plants in
our collections are similar with these forms. She also grows nature-reserves,
so her survival in this area doesn't seem to be threatened.
These plants also have their own special characteristics which
clearly deviate from the type-form.
The differences with other populations that strike the eye the
- the plants show a great tendency to sprout, about 30% of them
sprouts in nature
- they have a plain hard-green colour
- they have a thick taproot
- their ribs are sharply angular
- the flowerstalks are relatively long and remain a long time
- seedlings have usually sharply angular ribs, they are dentated
and have relatively large leaves which stay alive much longer.
N.E. Brown noticed these
differences too and came to the conclusion that a misunderstanding
that has lasted for more than a hundred year, should be corrected.
He did this by means of describing a new species: Euphorbia falsa.
He did however emphasize the deviating characteristics to much
by stating them to be fixed rules. For example, he stated that
all plants of Euphorbia falsa were ramified. This couldn't last
of course and so E. falsa soon became synonymous with Euphorbia
meloformis. So the species Euphorbia falsa didn't last for long.
Nevertheless these plants from Grahamtown do differ from the type-form
and to deal with these differences taxonomicly Gerhard Max described
the plants from Grahamstown as 'forma falsa' in the Euphorbia
Study Group Bulletin.
In contradiction with the previous mentioned localities of Euphorbia
meloformis this locality north of Peddie was not discovered untill
the middle seventies. And again this locality is about 100 kilometers
futher to the east.
Quite soon after the discovery of this locality plants from this
place were send to Dr. Dyer. Because these plants were so big
( almost 20 cm in height and diameter) he stated that the plants
must have been overfed by growing in a very nitrogenous kind of
soil. This reaction is not so surprising, but if Dr. Dyer would
have visited the locality himself he would have come to another
Later he did so anyway, because on the herbariummaterial of Euphorbia
meloformis from that locality he wrote"subspecies magna"
and changed that a bit later even in "forma magma".
Gerhard Marx shared this view by describing these plants as forma
magma in the Euphorbia Study Group Bulletin.
In november 2001 we visited this locality. We were very impressed
by the size of the plants. The plants grew in very short and dry
grass what made them even more striking. Futhermore the plants
had a uncommonly grey/green colour, most of the bigger plants
had up to 14 ribs and none of the plants had dryed flowerstalks.
These are chararteristics which make them clearly different from
the plants in the other localities. I think the pictures will
speak for themselves.
We had had to search a long time for these plants but the plants
sure were worth it!
E. meloformis ssp valida grows quite big, with 8 marked
ribs and big thorns
Euphorbia valida can
and may not be absent at this discussion of Euphorbia meloformis.
Their localities are adjacent and in historie the two species
often have been compared and mixed up. This is not very strange
because they have more similarities then differences.
Euphorbia valida was described in 1915 by N.E. Brown. He named
her 'valida' because he thought the plant was 'valid' (sound).
White, Dyer and Sloane spoke of an appropiate name.
This lasted for 80 years, until 1998 when Gordon Rowley degraded
Euphorbia valida to be a subspecies of Euphorbia meloformis. Seen
the great similarities this sure can be justified, though there
are some stable differences. Like the fact that Euphorbia valida
becomes much bigger (up to 45 cm), their flowerstalks remain on
the plants for a long time and they have a remarkable striped
pattern on the body.
Dikkop Flats, locality of E. meloformis
Euphorbia valida has
localities as well as at Janssenville as at Somerset East, at
the Springbokvlakte near Steyterville and at the Dikkop Flats.
The most known locality is the Dikkop Flats, it is a bit more
nothren of Grahamstown as the locality of E. meloformis. They
are only separeted by the about 10 km long Hells Poort.
Of these four localities the plants of the Dikkop Flats become
the biggest and these of the Springbokvlakte stay the smallest.
Present formal status
Like mentioned before Gordon Rowly stated in 1998 in the Euphorbia
Study Group Bulletin Euphorbia valida to be a subspecies of Euphorbia
meloformis. Immediately after that Gerhard Marx placed in 1999
in the same journal yhe plants from Grahamstown as forma falsa
and the plants north of Peddie as forma magna under Euphorbia
meloformis subspecies meloformis.
So the picture looks like this:
meloformis Aiton 1789.
ssp. valida (N. E. Br.)Rowley.
falsa (N. E. Br.) J. G. Marx.
magna R. A. Dyer ex J. G. Marx
This classification mentioned
above justifies the present knowledge of the group of forms around
Euphorbia meloformis and the history of this species has been
left unimpaired as much as possible.
However it might have been better to give the forma magma the
same rank as the subspecies valida.
The forma magma distinguishes itself more from the forma meloformis
as does the ssp. valida from de ssp. Meloformis. Above that a
forma is always based on a single characteristic feature like
the colour of the flowers or on a single deviating indivudual.
That’s why a rank of variety fits the plants from the surroundings
of Grahamstown better.
Koppie with E. melof. ssp. melof. forma falsa. J&R 102.
E. meloformis ssp. meloformis forma falsa. See its dried
flowerstalks bent ober the plant
In 1999 we visited a
very small locality of Euphorbia meloformis ssp. meloformis forma
falsa, this is its official name now. The 'koppie', at the edge
of Grahamstown, was about 200 square meters and some 150 plants
grew there. The plants were relatively small, more than half of
the plants was sprouting and they had a beautiful striped pattern.
Above this they had a very thight bunch of dried flowersstalks.
These stalks were bent quite strongly over the plant. This made
the plants well hidden between the grass.
The plants from this population keep the mentioned differences
in culture too, because little seedlings also show the striking
This all is just an example of how unique and valuable this species
with its many appearances is.
Two years later we visited
this place again and after searching thoroughly we couldn't find
more than 14 plants. The population was decimated. Probably the
hope that all the different localities will be preserved will
be false, certainly if we look at the situation which South-Africa
is in at this moment.
It is of most interest that some Euphorbia-specialists grow these
plants further, separated by locality, and make sure that the
material will be spread among those who are interested. Only then
the unique characteristics of a certain population can be preserved.
To my opinion this is more important as the exact name on the
label, it could be just 'Euphorbia meloformis', or not? A regular
Marx, J. G., (1993) The Sub-globose Euphorbias and Relatives,
Aloe 30, No. 3/4.
Marx, J. G., (1988) Euphorbia meloformis Aiton & Euphorbia
valida N. E. Brown, Some Observations in Habitat, The Euphorbia
Journal, Vol. 5, blz. 95 – 103.
Marx, J. G., (1999) The South African Melon-shaped Euphorbias:
The full Picture as known to Date, The Euphorbia Study Group Bulletin,
Vol. 12, No.1.
Mitich, Larry W., (1983) The Subglobose Euphorbias, The Euphorbia
Journal, Volume 1, blz. 32 – 41.
Rowley, G. D., (1998) Euphorbia Meloformis and E. Obesa, with
two newly assigned Subspecies, The Euphorbia Study Group Bulletin,
Vol. 11, No. 3.
White, A., Dyer, R. A., & Sloane, B. L., (1941) The Succulent
Euphorbiae (Southern Africa), 2 Vols