Your support is critical to our success.
Origin and Habitat: Somalia, Nugaal Region. Type locality: 49 km South of Garoe (Garowe), not known elsewhere.
Altitude range: 725-800 metres above sea level.
Habitat and ecology: Euphorbia globulicaulis occurs on limestone slope, rocky with stony soil and low Commiphora or Acacia scrub. This tiny plant is visible only at times of good rain, when its small globose fleshy stem swells and just protrudes above the soil. It is extremely rare in cultivation and may prove ephemeral.
- Euphorbia globulicaulis S.Carter
Description: Euphorbia globulicaulis, reputedly the smallest of all succulent Euphorbias. In its natural habitat is a geophyte perennial herb 3-5 cm tall, with and underground subglobose fleshy stem less than 3 cm in section, which does not make any branch growth above ground whatever apart from a leaf rosette, flat on the ground. John Lavranos first collected this plant during a 1985 expedition to Somalia. It was published it Volume 4 of the Euphorbia Journal as Euphorbia sp. aff. longituberculosa. It is apparently short lived in cultivation.
Derivation of specific name: The specific name 'globulicaulis' comes from the Latin words 'globulus', globule, little ball and 'caulis', stem.
Stem: Subglobose succulent 2–3 cm in diameter, sparsely covered with tiny tubercles in spirals formed by prominent leaf-scars. Branches few to several from the stem apex, somewhat fleshy, to 3 cm long, sparsely tuberculate, mostly underground. In cultivation, the tuberous stem may be exposed as a caudex.
Leaves Forming a basal rosette at the top of the stem, 1–15 mm long, 6–10 mm wide, ovate with rounded apex, margin undulate: Petiole 2–5 mm long.
*Inflorescences (cymes): 2–3 from the branch apices, forking 2–4 times with peduncles 5–15 mm long. Bracts sessile, ovate, 4–6 mm long, 3 mm broad, those at the base larger and similar to the leaves.
Flowers (cyathia): 1.5 mm in diameter. Nectar gland 1, tubular, the lateral margins curled inwards and joined to form a tube 1 mm long on the outside of the involucre, the mouth of the tube shorter than the fringed lobes. Styles 1.5 mm long, joined at the base, erect, with shortly bifid apices.
Blooming season: It was observed flowering and in fruit in habitat during October and November.
Fruits (capsules): Exerted on a recurved pedicel 3.5 mm long, shallowly 3-lobed with truncate base, 2 x 2.5 mm.
Seeds: Conical, 4-angled, with a horizontal ridge and acute apex, 1.5 x 1.3 mm, smooth, greysh.
Related species: Euphorbia globulicaulis is related to Euphorbia longituberculosa by the tubular structure of the cyathia but differs in its glabrous body and smaller ovate, almost crisped leaf margins.
Bibliography: Major references and further lectures
1) African Plants Database (version 3.4.0). Conservatoire et Jardin botaniques de la Ville de Genève and South African National Biodiversity Institute, Pretoria, "Retrieved 13 January 2016 ", from <http://www.ville-ge.ch/musinfo/bd/cjb/africa/>.
2) "Flora Somalia", Vol 1, (1993) Author: by S. Carter (Euphorbia, Monadenium), M. G. Gilbert (Acalypha, Andrachne, Antidesma, Bridelia, Caperonia, Cephalocroton, Chrozophora, Clutia, Dalechampia, Flueggea, Givotia, Manihot, Meineckia, Micrococca, Oldfieldia, Phyllanthus, Ricinus, Suregada, Tragia), and M. Thulin (Croton, Drypetes, Erythrococca, Excoecaria, Jatropha, Spirostachys and Thecacoris) [updated by M. Thulin 2008]
3) Urs Eggli, Leonard E. Newton “Etymological Dictionary of Succulent Plant Names” Springer Science & Business Media, 29 June 2013
4) Urs Eggli “Illustrated Handbook of Succulent Plants: Dicotyledons” Springer Science & Business Media, 2002
5) Tom Knapik “WHAT'S THE STATUS? by Topic #3: Euphorbia globulicaulis S. Carter” in: Espinas y Flores, Newsletter of the San Diego Cactus and Succulent Society, Inc. Affiliated with the Cactus and Succulent Society of America Volume 34, Number 9, Saturday October 9, 1999
6) John Lavranos. Euphorbia Journal Volume 4
7) Susan Carter Holmes Kerr Bulletin v.45: p.655. 1990
Cultivation and Propagation: Euphorbia globulicaulis is believed to be a short-lived perennial, rarely living over the age of 2-4 years, which may account for its rarity in cultivation, but a beautiful one none the less, that requires our special attention. It has been propagated by seed only. It does not require cool temperatures for its growth cycle or flowering, and it has not an apparent dormancy period but periods where the emergence of new leaves stops and older leaves wither and drop. Euphorbia globulicaulisis a particular favourite of caudiciform plant enthusiasts. Cultivation of this plant is the same as that for the other tuberous varieties of Euphorbia from tropical areas (Madagascar, and central Africa), but it is not the easiest of all caudiciform Euphorbias. It is particularly prone to rot if left cold and damp while dormant.
Caudex exposure: The remarkable spherical stem (caudex) is usually raised above the soil line so that this can be seen and more readily appreciated.
Soil and pots: It likes pots with generous drain holes, needs a very airy potting medium which mainly consists of non organic material such us clay, pumice, lava grit, and only a little peat or leaf-mould, seeing that the main trunk is planted with the majority of the roots below the caudex line. It's rare that it will use the upper third of its soil and often this area serves like a mulch or support for the stem.
Fertilization: Need a perfect fertilizer diet in summer. Use preferably a cacti and succulents fertilizer with high potassium content including all micro nutrients and trace elements or slow release fertilizer.
Exposure: This plant has an excellent heat tolerance, and need full sun to light shade exposures, but can tolerate shade.
Watering: Water regularly during the active growing season. No water should ever be allowed to stand around the roots. Keep almost completely dry in winter. Even though the swollen caudex ensures a long lasting water reserve making it very tolerant of under watering, this euphorbia is difficult, turning immediately to mush when over watered, or watered out of season. Care must be given in watering, keeping them warm and wet while growing, and cooler and dry when dormant.
Hardiness: Tender. This spurge can be difficult to get it to look its best without a good amount of heat and sun and so it is only really suited to the tropics (USDA Zones 10-11). Keep the plant cooler in winter, but maintain the light as bright as you can so that any growth which it may produce at this time will not be etiolated. Protection in a warm greenhouse in the middle of the winter will greatly increase the survival rate.
Rot: Rot it is only a minor problem with Euphorbias if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much. It is very unlikely to lose this plant from root rot from excessive water.
Known hazards: The latex/sap is poisonous and can cause skin rash, itching and general discomfort, and they should be handled with caution, particularly when pruning.
Propagation: The plant can be only reproduced by seeds.
|Back to Euphorbia index|
|Back to Euphorbiaceae index|
|Back to Succulents Encyclopedia index|