Maerua angolensis var. heterophylla Welw. ex Oliv.

Abreu, J. A., Martins, E. S. & Catarino, L., 2014, New species of Maerua (Capparaceae) from Angola, Blumea 59 (1), pp. 19-25 : 21

Maerua angolensis var. heterophylla Welw. ex Oliv.

The variety heterophylla of M. angolensis was published by Oliver (1868: 86) in Flora of Tropical Africa, based on Welwitsch 968b, but there are no other known collections identified as this variety. Having examined all the material from M. angolensis housed in LISC, LISU and COI herbaria, we verified that the species shows a large variation in the size and shape of leaves, ranging from rounded or broadly elliptic to narrowly lanceolate. One trend in the species leaf shape is that specimens collected in the Angolan inland have leaves broader than those collected in the coastal regions.

The leaves of the type collection, made near Luanda, are narrowly lanceolate, very long, and seem to be the extreme in the range of variation of the species. On the other hand, a collection made by E. J. Mendes in the Namibe area, southwest coastal region of the country (Mendes 1242) exhibits elliptic as well as narrowly lanceolate leaves in different shoots of the same individual (ascertained by the collector on the herbarium sheet). Both Welwitsch and Mendes collections are from small plants, probably juvenile, and the narrowly lanceolate leaves seem to be from long, rapid growing branches .

Therefore, having examined all the M. angolensis collections available, including the two that can be considered as having the characteristics of the var. heterophylla (Welwitsch 968b and Mendes 1242) we consider that there is no reason to keep this variety as a good taxonomical entity.

In a study on Maerua from the Ethiopian flora, Kers proposed the creation of two subspecies for M. angolensis : subsp. angolensis and subsp. socotrana (Schweinf. ex Balf.f.) Kers (1993: 54) . All the Angolan specimens fall into M. angolensis subsp. angolensis .