Synonyms:

Euphorbia cucumerina
Euphorbia obesa subsp. symmetrica
Euphorbia symmetrica
Baseball plant
Basketball plant

Habitat:

E. obesa is native to Cape Provinces, South Africa. It grows mainly in Great Karroo, the Northern Cape region and in the Graaff-Reinet district in the Eastern Cape. This succulent grows up to 900 m in altitude in the hilly and rocky regions, its color allow the plant to blend into its habitat. The plant can grow in in full sun and with high average temperatures, and is used to variable rainfall.

Description:

E. obesa is a succulent of the Euphorbiacee botanical family. The shape of the plant is the reason of its name, the succulent has a ball-shaped stem indeed. The plant can reach up to 10 cm in diameter and up to 30 cm in height. Normally the plant is a solitary succulent, but sometimes the plant branches out forming small balls at the base of the stem. The color of the stem ranges from bluish-green to light brown and the stem has transverse red-brown bands and longitudinal tubercles that resembles seams. The stem is spherical in young and can become cylindrical or cone with age. Leaves are very small and soon drop off, but there is the stem that can photosynthesize. Ciathya are the typical inflorescence of the Euphorbia, it is an inflorescence consisting of a cuplike cluster of modified leaves enclosing unisexual flowers. This species has small, greyish green cyathia normally being all male on some plants, or all female on others. Because there are male plant and female plant, cross pollination is required that is normally carried out by insect. Flower are borne at the apex of the stem along the top of the angles of the ribs. E. Obesa has a particular way of spreading its seeds: the fruit is a slight 3-angled capsule that when ripe explodes and shoots away the seeds it contains. Seeds are small, rounded and light so as to favor the propagation up to a few meters away and have a more uniform spread over the territory.

Cultivation:

This is a slow growing succulent but quite easy to cultivate. The Obesa can be placed in both direct sun light and light shade, but if you first place it in light shade and then decide to move it outside to direct sunlight, do so gradually to allow the plant to get used to it. You can place the plant on a windowsill where can receive the sunlight for only part of the day. The soil should be mixed with pumice, clay and loam to allow the drainage and prevent the root rot, the plant is prone to it indeed. Remember to use perforating pot to drain excess water. Watering should be done thoroughly: during the vegetative period you can water regularly the plant (every 10 days), checking that the soil is completely dry before watering again; in winter you should stop the watering to allow to the plant to enter dormancy. If you want a very fast and lush growth you can fertilize the plant during the growing season with the specifics fertilizers for cacti, otherwise an NPK fertilizer will be perfect; stop fertilizing throughout the winter. If the pot starts to be too small for the plant you can repot the plant in a pot 2 cm wider. Handle the plant carefully and wear gloves because the latex it exudes is toxic. The plant can tolerate temperatures as low as -5°C but it is better for the plant to remain at temperatures above 8 C°.

Propagation:

Propagation can be done by seed or cutting. By seed is not very simple to propagate the plant because the germination occurs within 3 weeks, during the spring-summer you can sow the seed in a sandy loam soil and keep it with high level of humidity. By cutting you can use the offsets that grow at the base of the plant. Cut the offset as close as possible to the base of the stem and then let it dry; after a few days the cut surface will dry and a callus will form, then place the cutting in a mixture of sand, soil and pumice.

Curiosity:

Species of the Euphorbiacee family normally if are damaged, exude a white milky sap, called latex. Many plants produce latex, but in the Euphorbiacee this latex is often poisonous and may irritate skin. The poisonousness is due to some alkaloids so it is best to keep the plants away from children or pets. Euphorbia Obesa is a wonderful example of convergent evolution. In fact, it incredibly resembles Astrophytum asterias.