Euphorbia rhombifolia

Euphorbia rhombifolia, in Afrikaans the bloumelkbos (blue milkbush) or soetmelkbos (sweet milkbush) and botanically previously E. decussata, is a densely-branched, spineless shrub that spreads and reaches 1 m in height. 

In South Africa the species occurs mainly in the east of the Western Cape, the western coastal plains of Namaqualand and the Richtersveld in the Northern Cape, the karoid west of the Eastern Cape and the far southerly border of the Free State. The photo was taken at Goegap near Springbok.

The habitat is arid and semi-arid sandy flats and karoid scrubveld, the plants often forming small colonies. The species is not considered threatened in habitat early in the twenty first century.

The species is not browsed but not toxic to game and stock either; merely low in palatability.

A traditional alcoholic beverage, a mead, was in the past (or is still) brewed using this plant as yeast. To those users of the plant it was known as kirriemoer or sikkiriwortel (sikkiri root), suggesting that the plants were dug up for accessing the roots to make the yeast. Moer is (among other things) a local name for yeast, while kirrie is a form of the karee common name of Searsia and also taaibos trees and shrubs, the fruits of which featured or feature in the brewing of mead.

When driving for long hours through the arid inland, pick the most likely, lonely little house in the distant Karoo veld to ask for a taste of the local mead brew. But wait until the police van has disappeared over the hill as conjuring alcoholic beverages out of anything without a licence interests them (Vlok and Schutte-Vlok, 2015; Williamson, 2010; Shearing and Van Heerden, 2008; Van Wyk and Gericke, 2000; Gledhill, 1981; iNaturalist; http://redlist.sanbi.org).