Notes on Two Brazilian Species of Lippia (Verbenaceae)

Abstract

Summary. A discussion of the nomenclature of two Lippia species is presented. Plants currently called L. microcephala Cham. and L. iodophylla Schauer should be called L. hermannioides Cham. and L. triplinervis Gardn. respectively. In 1832 Chamisso described two new species of Lippia, L. hermannioides Cham. and L. microcephala Cham. from material based on Sellow collections from Minas Gerais. These two taxa were obviously closely related as Chamisso stated 'This [L. hermannioides Cham.], with the subsequent species [L. microcephala Cham.], very closely affiliated but differs from it by pubescence, shape of leaves, bracts and capitulum, large flowers, smaller calyx....'. The holotype material of these species, held in Berlin, was destroyed during the 1939-1945 war, but photographs taken prior to their destruction are housed at the Field Museum of Natural History, Chicago. Examination of these photographs (Macbride nos. 17525 and 17513) and further Sellow specimens at Kew which appear to be isotypes along with other material collected since then, has led me to believe that Chamisso's names probably represent the same species. The centre of origin for these plants would appear to be in and around the Diamantina area of Brazil and particularly on the Serra da Cara;a, although one Martius collection, Herb. no. 1038, studied, was from Rio de Janeiro province and another was collected by Glaziou from Goyaz. Within this area there appears to be a wide range of morphological forms which may justify considering infraspecific taxa within the one species. However, without examination of the complex in the field, this is not possible. The name for this polymorphic species has unfortunately been wrongly applied. Moldenke (1965), in his notes on Lippia, called this species L. microcephala Cham. putting into synonymy L. hermannioides Cham., L. viscosa Casar and L. triplinervis Gardn., following Schauer. According to Article 57.2 of the International Code, which states that when uniting taxa of the same rank the name used by the first person to unite those taxa must stand as the correct name and so Hiern, who in 1877 retained the name L. hermannioides Cham. with L. microcephala Cham. in synonymy, should be followed. Of the other two names mentioned in the paragraph above, the first, L. viscosa, has never been validly published. It exists only as a name written on