Sarcocaulon (2017)

By Bob Williams (January 2017)

Sarcocaulon is a genus found in the Geraniaceae family. Depending on the source of information, there are five to seven genera inside this family. According to the Plant List website, there are 621 accepted species names for this family.

The species that members of this club are most interested in growing are found in the genera Monsonia, Pelargonium and Sarcocaulon. Some sites I found consider Sarcocaulon part of Monsonia. The number of species within each genus seems to vary. Hopefully, the number will stabilize in the near future.

Sarcocaulons are displayed most often as bonsai plants. The low-growing nature of the plants, along with the delicate foliage, create a stunning display.

The name Sarcocaulon comes from the Greek words for fleshy, “sarkos,” and stems, “caulon.” These plants also go by the nickname of “bushman’s candle.” This is because the plants grow as a small shrub in habitat and have woody trunks and branches. Due to the harsh conditions in which they grow, the bark has a waxy coating. Even after the plants die, the coating remains. The wax and the woody skeletons create a natural torch that can be lit wet or dry.

Members of the genus Sarcocaulon are spiny, fleshy shrublets with delicate white, yellow or salmon-pink flowers about 1 inch across. The plants grow in the arid western portions of South Africa to northern Namibia. One species is found in the far southern region of Angola near the South African border.

The plants can grow to a height of 12 inches and be 20 inches in diameter. The majority of the plants are only half that size. Branches are about 0.5 inch in diameter. These plants invariably grow in full sun, often exposed to severe winds.

Some species prefer sandy flats, while others grow best in rocky places, but good drainage is the most important environmental factor where they are found. Sarcocaulons are extremely xerophytic and intolerant of prolonged wet conditions. Some species have spines, and some are spineless.

The regions where these plants grow get very little rain – 5 inches or less annually. The summers are very hot. This explains the waxy coating. The rainy season, such as it is, occurs in the fall, when temperatures moderate. Sarcocaulons lose their leaves in the spring and remain dormant during the hot, dry summers. In fall, leaves appear.

The leaves are a striking feature of this plant. They are small, rarely reaching 0.5 inch wide, and go the entire length of the branches. Most commonly, the leaves form small leaflets that grow from the base of the branches in pairs. S. crassicaule and S. pattersonii have this type of leaf.

The other form has small feather- or fernlike leaves that give an extremely delicate appearance. S. herrei and S. multifidum are examples of this leaf type. On those plants that have spines, the petioles (leaf stalks) of each leaf turn into spines when the leaf dies.

These plants are best grown in a well-drained, gravelly mixture in an area that receives long periods of strong sunlight. They should be watered once every six to 10 days during periods of active growth and leaf production. As soon as the foliage starts to show signs of yellowing or withering, water should be stopped. If your plants are outside during the summer, they should get full sun, but no rain. There should be plenty of air circulation around your plants. Overwatering is the death knell for these plants.

The best way to start the plants is by seed. Seeds should be sown just under the surface of the soil. They should be repotted into individual containers when they are about 2 years old. Seedlings need to be regularly watered while in active growth and occasionally during dormancy. Expect slow growth.

Sarcocaulon plants are readily available from vendors, but can carry hefty prices. Small starter plants in 2-inch pots can be found in the $8 to $15 range. Plants in 4-inch pots can be found in the $20 to $40 range. Specimen plants cost $100 plus. The holy grail of all sarcocaulons is S. peniculinum. It is rarely seen for sale. A 4-inch unbranched plant sold for $800 on eBay in October.

Two good sources of information:

African Succulents – http://www.africansucculents.eu
Plantzafrica – http://www.plantzafrica.com/plantqrs/sarcocaulon.htm
This website is maintained by the South African Biodiversity Institute.