Euphorbiaceae Archives - Page 2 of 6

Euphorbia meloformis ssp. meloformis

One does not have to be a linguist to surmise that meloformis means shaped like a melon. Judging from the old synoniems pomiformis and pyriformis, the plants may also resemble an apple resp. a pear.
Usually the stems are single, more or less ball-shaped, to 10 cm tall and in diameter, with mostly 8 ribs and a depressed top.
The plants occur on gravelly flats in the Eastern Cape Province, mainly in and around Grahamstown, Uitenhage and the Coega area.

In ssp. valida (Euph. valida), the stem may become over 30 cm tall and 12.5 cm thick, with a rounded top and harder and more persistent peduncles.

Euphorbia gamkensis

Mature plants of this species usually have a globose caudex to 10 cm tall and to 9 cm in diameter. The branches are about a cm thick and normally about 1.8 cm long.

The species is very rare and only occurs between Calitzdorp and Oudtshoorn in the Little Karoo. It was described in 1999, but nowadays the consensus seems to be that it should be incorporated in E. decepta.

Euphorbia eustacei (part 2 of 2)

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Euphorbia eustacei (part 1 of 2)

This species occurs in the western Karoo from Matjiesfontein to near Calvinia and is closely related to E. loricata and E. multifolia. (Peter Bruyns in “Plants of the Greater Cape Floristic Region”, published in 2013, even considers it a synonym of E. loricata).

The plants form rounded cushions to about 15 cm tall and to 30 cm or more in diameter, with many branches, which usually completely hide the main stem.
The 2-5 cm long white spines, which are in fact modified peduncles, are very obvious in the dry season; in winter and spring they are partly hidden by the up to 4 cm long leaves.

Euphorbia septentrionalis ssp. septentrionalis

Plants belonging to this subspecies occur fairly widespread in northeast Uganda and northwest Kenya in sandy rocky soils, usually in the open at altitudes between 1075 and 1850 m.

They have a thick fleshy root with densely tufted, more or less round branches, which are 5-8 mm thick and erect to 15 cm tall or creeping to 50 (-100) cm long.
The branches bear tubercles to 2 cm apart in 4 series, with triangular spine shields 6 x 1.5 mm in size and spines 5-15 mm long; they differ considerably in colouring, from bright green often with darker longitudinal stripes to greyish-green with purplish stripes.

Cultivated plant

Euphorbia capsaintemariensis

There is only one place in the world where this species is known to occur: Tanjona Vohimena, the southernmost tip of Madagascar*.
On this stark, wind-swept limestone terrace about 100 m above sea level, the species occupies an area of less than a km².
Old plants possess a large turnip-shaped root to 30 cm long and to 10 cm wide, topped by a densely branched crown to 30 cm in diameter. In habitat the branches creep along the ground as a result of the constant wind; in cultivation they are more or less erect.
The leaves form rosettes at the tips of the branches, they are to 25 x 8 mm in size and green to red-brown.

* The old name for this is Cap Sainte Marie, which explains the specific epithet.

Plant in cultivation; scanned slide

Euphorbia hamata (incl. peltigera)

Hamata means hooked, an apt specific name for this species with its recurved tubercles.

The plants often form dense, much-branched clumps up to about 50 cm tall and 60 cm or more in diameter with a thickened main stem.
The flowers (cyathia really) are surrounded by green or yellowish to red bracts and appear from April to September.
One can find this species from Luederitz in southern Namibia to SE of Worcester in the Western Cape, usually on stony slopes.

Euphorbia primulifolia (var. primulifolia)

At the end of our latest trip to Madagascar, we stayed in Antsirabe, south of the capital Antananarivo. The area is well known for its succulents and I decided to spend an afternoon in the mountains surrounding the town. For several kilometers the road leading out of town ran through the middle of a wide valley, and what I could see of the mountain slopes did not look promising at all. At a certain moment we decide to take a little side road that seemed to take us out of the valley. This was indeed the case, but even the hillsides appeared to be cultivated.
When the driver asked talked some local people if there were any bare rocks nearby, he got a positive reply, but in spite of their directions no rocks came into view. At a loss what to do now, I decided to just stop at an uncultivated spot and look around.
Picture #1 shows the first plant that I noticed there. Without flowers it could be about anything, but next to it was a group of flowering plants (#2) and immediately the penny dropped.

With a large tuber 10-15 cm long and to 7 cm thick, Euph. primulifolia is a true geophyte. It has a very short stem, hidden in the ground, with a radial rosette of 4-12 leaves. In the dry season the plants are leafless and hidden in the grass; in other words, they are only visible in the rainy season. This growth form allows the plants to survive the yearly grass burning.
The leaves are flat or undulate, 8-11 cm long and 3-4 cm wide.
Usually the plants flower before the leaves appear, but as the pictures show, this was not the case here. The cyatophylls* vary from white or greenish to pink and violet.

This variable species is widespread in the central highlands at about 1400-1500 m in a variety of substrates.

* cyatophylls are the bracts that surround the inflorescence proper in many members of the Euphorbiaceae.

Plant in cultivation. Scanned slide.

Euphorbia multiclava

This distinctive species forms clumps to 30 cm tall and 40 cm wide by branching dichotomously (an uncommon thing in the genus).
The branches are usually 2-3.5 cm thick and 2-7 cm long, with 10-16 ribs.
The plants grow in the eastern part of Somaliland at altitudes between 1200-1500 m on open plains where the topsoil is often a layer of powder-like limestone.

Plant in cultivation; scanned slide

Euphorbia dregeana

As the first picture shows, these up to 2m tall, dense clumps are very conspicuous in the field.
The branches are yellowish-green to grey-green, usually up to 3 cm thick at the base and 1.2 cm in diameter above, with leaves that soon disappear.
Between July to September one can find the plants in flower.

The plants occur mainly in flat open gravelly or sandy plains, sometimes on low stony slopes. They are widely distributed from the Haalenberg east of Luederitz in Namibia to Kamieskroon in Namaqualand and Namies in Bushmanland.