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.
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
In the dormant state, without leaves and flowers, this species is difficult to distinguish from P. densiflorum and P. rosulatum. They share the same habit: low, multi-branched shrubs up to 1.5 m in diameter and up to 1 m tall.
P. horombense is named after the Horombé plateau in the southern highlands of Madagascar, where it often occurs in great numbers on granite rocks.
The inflorescence has an erect peduncle of no less than 60 cm tall, with broadly cup-shaped flowers 1.7-2.3 cm in diameter.
According to Werner Rauh in his great book on the succulents of Madagascar, this is:
“the most beautiful Pachypodium species in cultivation”.
For a little prologue to this post, see the preceding one: Kalanchoe integrifolia).
Although Mt. Ibity is perhaps the most accessible place, P. brevicaule also occurs in a couple of other habitats in Madagascars central highlands.
Plants can be found from Ambositra to Antananarivo in quartz rock at altitudes between 1400 and 1600 m.
In some spots where P. brevicaule grows together with P. densiflorum or P. rosulatum, one can come across hybrids. Judging from the long flower stalks, I suppose the plants shown in pictures # 3 and 4 belong to either of these hybrids.
The first two pictures show views from where P. brevicaule grows on Mt. Ibity. On # 2 you can see the quarry belonging to the massive cement factory nearby.
Attractive dwarf shrublets up to 15 cm tall with a caudiciform base up to 3.5 cm in diameter.
Branches are short and fat, with peeling yellow-brown bark; covered with flat white phyllopodia (leaf-bases) when young. The leaves are usually up to 4 cm long and 5-7 mm wide.
The flowers are tubular, erectly spreading to pendulous and relatively large (up to 1.8 cm long). They appear in November and December.
This species is widely distributed from southwest Namibia to the Knersvlakte, on flats and stony slopes, often with quartz rocks or pebbles.
Rainfall in the area is 100-200 mm per year, mainly in winter. The temperatures are high in summer and moderate in winter, sometimes with light frost.
Of the about 900 species of the Pumpkin Family (Cucurbitaceae), nearly 10% can be classified as a caudiciform succulent. The subject of this post is a clear example.
It is a climber with a tuberous rootstock 15-20 cm across, which is visible above ground and tapers into the stems which may be up to 7 m long.
Young stems are green and soft, soon becoming dark green, grey or brownish and somewhat woody.
The plants are dioecious (either male or female) and produce egg-shaped
fruits which are bright red, up to 7 x 3 cm and beaked (=rostrata).
The species occurs in deciduous bushland, thicket , woodland and wooded grassland from sea level to 1650 m in tropical East Africa: southern Ethiopia and the adjacent part of Somalia, northeastern Uganda, Kenya, northern and central Tanzania.
The pictures were taken in Kenya and northern Tanzania, except for the last one, which shows a young plant in cultivation.
The fact that this species is a deciduous geophyte is reflected in the name, as one of the meanings of the word resurgens is: “Rising again, as from the dead”.
The plants are only up to 3 cm tall, with a thick caudex covered in cork, short stems and
leaves with large bladder cells.
In June-September they produce greenish yellow to pale salmon, distinctly scented flowers about 4 cm in diameter.
If you want to see the plants in nature, you have to go to the Northern or Western Cape Province, where they are widespread in the winter rainfall area from Namaqualand to Ceres and Laingsburg.