Introduction

The genus Stylosanthes Sw. has a disjunct distribution; two indigenous species have been reported in Africa, one in Asia and the remaining species occur in the Americas (Nooteboom 1961; Mannetje 1984). The genus is economically important in tropical and subtropical regions of the Americas, Africa, Asia and Oceania (including Australia) (Chakraborty 2004), where some indigenous and introduced species are used as forage, for soil cover and improvement, and in the production of concentrate feed for livestock, among other uses (Cook et al. 2005). The genus comprises about 25 species, notwithstanding that up to 50 names can be found in the taxonomic literature. However, some of these species are poorly delimited (Klitgaard & Lavin 2005).

Stylosanthes hispida Rich. was effectively and validly published by Richard (1792) from material collected within the boundaries of what is known today as French Guiana and it is one of the oldest published names within the genus. However, due to its morphological similarity to S. guianensis (Aubl.) Sw., some authors have treated it as synonym of S. guianensis (Mohlenbrock 1957; CONABIO 2008). However, none of the authors listing S. hispida as a synonym of S. guianensis has cited a type specimen or original material of S. hispida. They rather synonymised the species based on Richard’s short description (Richard 1792) (Fig. 1).

Fig. 1
figure 1

Original description of Stylosanthes hispida Rich. Richard (1792). Image from the Biodiversity Heritage Library. Digitised by Ernst Mayr Library of the Harvard University.

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During the preparation of a taxonomic revision of Venezuelan Stylosanthes (Calles & Schultze-Kraft 2010), it became evident that S. hispida (though not native to Venezuela) had never been formally typified. According to Turland (2013), however, untypified names are potentially unstable because it might be traditional usage which is determining the application of the name rather than the type. Therefore, to foster nomenclatural stability within the genus Stylosanthes, we here designate a lectotype for the name S. hispida together with some explanatory notes.

Material and methods

Information on herbarium specimens was gathered during a visit to P and through consultation of the database in the herbarium at G. High-resolution images presented in this publication were downloaded from the websites of the Muséum National d'Histoire Naturelle, Paris, France and the Biodiversity Heritage Library (biodiversitylibrary.org) and are reproduced with permission. Literature referring to Stylosanthes hispida was either consulted at the library of the Royal Botanic Gardens, Kew or downloaded from the Biodiversity Heritage Library. Barcode numbers of specimens, if available, are placed in square brackets after the herbarium acronym. Herbarium acronyms used follow Thiers (2008).

Typification

Stylosanthes hispida Rich., Actes Soc. Hist. Nat. Paris 1: 112 [erroneously numbered as 105] (Richard 1792). Lectotype (designated here): French Guiana, Richard s.n. (P! [P00202653]) (Fig. 2).

Fig. 2
figure 2

Original material from Richard’s collection (barcode P00202653), selected here as lectotype of Stylosanthes hispida Rich. Reproduced with permission of the Muséum National d'Histoire Naturelle, Paris, France.

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notes. Richard (1792) described the species Stylosanthes hispida but without making reference either to a herbarium specimen or an illustration. Since Stafleu & Cowan (1983) indicated that Jean Baptiste Leblond’s collection is deposited at G, we first consulted the database in that herbarium; however, no specimen of Stylosanthes collected by Leblond could be found. Then we reviewed relevant literature (Stafleu & Cowan 1983; Thiers 2008) and consulted herbaria known to hold Richard’s specimens (i.e., G, P) and we found one element that is eligible to be designated as a lectotype of S. hispida, i.e., a specimen deposited at P (P00202653) (Fig. 2). This specimen displays a handwritten description of Stylosanthes hispida (most likely written by Louis Claude Marie Richard), and according to McNeill et al. (2012: Art. 9.3) this specimen should be considered original material of the name S. hispida. Since all characteristics of specimen P00202653 are in accordance with the original description and the specimen is housed in the herbarium where the author of the name worked, we designate it here as the lectotype of S. hispida.

In 2009, the specimen P00202653 was annotated as holotype of Stylosanthes hispida by the first author of this paper. However, for an element to be considered as a holotype it should have been designated as such in the original description (McNeill et al. 2012: Art. 9.1). Since Richard (1792) did not mention any element in his description of S. hispida, the specimen P00202653 cannot be treated as holotype of S. hispida. More appropriately it is considered as original material that can be selected as a lectotype (McNeill et al. 2012: Art. 9.3). Once this article is published, the authors will send the respective lectotype annotation label to the curator of P.