Endemic to South Africa
Boraginaceae, the Borage or Forget-me-not family, includes a variety of shrubs, trees, and herbs, totalling about 2750 species in about 150 genera worldwide (Stevens, 2009). The family is especially well represented in the Mediterranean region, but is also to be found in most temperate to subtropical areas (Heywood, 1993). Lobostemon Lehm., currently including 29 species, is the largest southern African genus in the Boraginaceae s.l. It is endemic to the region, mainly confined to the winter-rainfall area of South Africa, occurring from Springbok to Mossel Bay, and further eastward along the coast to about Grahamstown, where the rain occurs throughout the year.
Medicinal use
Agtdaegeneesbos (eight day healing bush), Douwurmbos (dew worm bush), Luibos (lazy bush) and Geneesbos (healing bush) are the popular vernacular names for Lobostemon known to most rural folk in the Western Province of South Africa, and to those interested in South African medical plants in particular. In the majority of cases the species in question is L. fruticosus (L.) H.Buek. The common names imply the use of Lobostemon for the cure of various ailments, especially those concerning wounds, blood poisoning, ringworms, skin diseases and syphilis. The remedies all require an infusion of the leaves or a paste is made by either pounding the leaves or chewing them—the slimy paste is then topically applied to the affected area (Watt & Breyer-Brandwijk, 1962; Van Wyk et al., 1997a). Members of the family are, however, a common source of pyrrolizidine alkaloids (Röder, 1995). These alkaloids are cumulative liver toxins and the use of food or products containing them should best be avoided (Bruneton, 1999).
Related to Echium
Lobostemon is considered to be sister to Echium L., the latter represented in South Africa mainly by the invasive E. vulgare L. and E. plantigineum L. (bloudissel, Paterson’s curse, viper's bugloss).The first Lobostemons to be described from the Cape were initially placed in Echium, but Echium is currently viewed to be a solely northern hemisphere entity. Echium consists of herbaceous forms confined largely to the continent and woody forms occurring principally on the Macronesian Islands. Any thoughts of ties between the woody Echiums and the woody Lobostemons have been disproven, the former representing a singular island colonisation event with corresponding recent speciation (Böhle et al., 2001).