The name Crassula is the diminutive of the Latin crassus, which means thick or fat, referring to the fleshy nature of the genus. The species name lactea (Latin), meaning milk alludes to the distinctive white dots (hydathodes) at regular intervals on the edge of the leaf, through which excess moisture is excreted leaving salts on the leaf. These dots give the leaves a stitched appearance, which has earned it the common name Tailor’s Patches. Crassula lactea was named by William Aiton (1731-1793), first Director of the Royal Botanic Gardens at Kew, in the first volume of Hortus Kewensis in 1789 from plants collected and introduced to England by Francis Masson in 1774,. Masson, a horticulturist from the Royal Botanical Garden, Kew, was sent to the Cape by Sir Joseph Banks to collect plants. He travelled widely, was an intrepid plant collector, who collected many plants new to science and introduced many Cape plants to Kew and was responsible for naming the quiver tree, Aloidendron dichotomum. The genus Crassula is very well represented in South Africa, where there are more than a 100 species, and the majority occur in the southern and western parts.

Fig. 7. Close-up of a leafy branch of Crassula lactea growing on a shale cliff with with Haworthia retusa var. turgida and Cotyledon hybrid at Valsriviermond, Gouritz River, Western Cape.

Crassula lactea belongs to section Anacampseroideae, which was created by Adrian Haworth in 1821 to accommodate the species with star-shaped flowers 2-10 mm long with spreading lobes at right angles to the pedicles, the petals without a dorsal appendage but sometimes hooded and anthers pink to lilac. Toelken acknowledges 10 species as belonging to this section: Crassula arborescens, C. cordata, C. crenulata, C. inandensis, C. lactea, C. multicava, C. ovata, C. pellucida, C. sarmentosa and C. streyi. Most of these species are frequently found in cultivation, the kerkei (Crassula ovata) is the largest species in the genus Crassula and perhaps the best known and often used as a hedge plant in South Africa and a pot plant all over the world.

Crassula lactea is related to both C. multicava and C. streyi. Crassula lactea is at once distinguished from C. multicava by its leaves which are markedly more succulent, rigid and the row of whitish dots (hydatodes) along its leaf margin. Crassula lactea also grows much more slowly than C. multicava, and is more difficult to grow. Crassula multicava forms dense mats, and with more or less 4 lobed flowers and its inflorescence is covered in adventitious buds, and is the most widespread of the two. Crassula streyi is a robust, sparingly branched plant, with leaves 40-65 mm long, often mottled, and yellowish-green flowers with a reddish central vein. It is confined to cliffs in northern Pondoland (Eastern Cape and KwaZulu-Natal).

Fig. 8. Crassula lactea habitat at Enon, Eastern Cape, on an Enon Conglomerate cliff face, sharing its habitat with Portulacaria afra, Curio ficoides, Caputia pyramidata and Aloe speciosa.