Rhododendron × intermedium, Wenderoth, 1825

Sosnovsky, Yevhen, Nachychko, Viktor & Mráz, Patrik, 2017, On the typification and nomenclature of Rhododendron × intermedium (Ericaceae), Phytotaxa 313 (2), pp. 195-202 : 196-197

Lectotypification of Rhododendron × intermedium

Tausch (1836a) wrote in the protologue that ca 15 years ago [i.e. around 1821] he observed a conspicuous taxon in the Lindacker’s herbarium which was misidentified with Rhododendron ferrugineum and which was probably collected in the Styrian Alps. Based on this indication, we tried to trace putative Lindacker’s specimen(s) which could be seen by Tausch. However, our search failed as we were not able to find where the herbarium of J.T. Lindacker (1768–1816) is actually located. According to the Index Herbariorum ( Thiers 2017) , Lindacker’s herbarium could be deposited at the National Museum in Prague (PR), thought the question mark accompanying the herbarium abbreviation suggests that this information is rather uncertain. This uncertainty was confirmed by Ota Šída, curator at PR, who has not been aware about any specimen of vascular plants collected by Lindacker and stored at PR but one (O. Šída, in e-mail). In addition, there was another unsuccessful search for syntype material of Potentilla lindackeri Tausch (1819: 466) collected by Lindacker ( Kirschner et al. 2007). Interestingly, as in the case of R. × intermedium, Tausch (1819: 467) noticed that the specimen of P. lindackeri was seen by him in the Lindacker’s herbarium kept at that time by C. Sternberg. C. Sternberg (1761–1838) was an outstanding Bohemian naturalist, sponsor and co-founder of the Bohemian National Museum (today National Museum, PR) where his collections are currently housed. Tausch’s notice and the facts that Lindacker’s mineralogical and paleontological collections were acquired by Sternberg for whom Lindacker had worked also as a custos ( Klášterský et al. 1982), would logically lead to the conclusion that Lindacker’s herbarium should be located at PR. However, according to Maiwald (1904), Lindacker’s herbarium encompassing ca 7,000 specimens was purchased by F.W. Sieber (1789–1844), traveller and plant collector from Prague. Although a considerable amount of Sieber’s material was distributed all over the world in the form of exsiccate specimens, his personal herbarium which included about 30,000 specimens was firstly acquired by C.L. von Reichenbach ( Anonymous 1864) and later on with the latter’s herbarium by H.F. van Heurck from Antwerpen from where Sieber’s herbarium moved to the Botanic Garden of Meise (BR; Stafleu & Cowan 1985). Our attempts to trace Lindacker’s specimen(s) of R. × intermedium at BR were again fruitless (P. Stoffelen, in e-mail). An important part of Sieber’s herbarium was, however, also a part of Tausch’s collection which was bought by count J. Nostitz partly for the National Museum (PR; one part of the Czech material) and partly for the Charles University ( PRC; Maiwald 1904).

Because we were not able to trace Lindacker’s specimen(s) of R. × intermedium , we examined Tausch’s herbarium, of which the major part is located at PRC. Here we found three specimens of R. ×intermedium that match the diagnosis, were identified by Tausch himself and which we consider to be a part of non-cited original material according to Art. 9.3 of the ICN ( McNeill et al. 2012):— GERMANY. Alpen Deutschlands, Strauch, s. d., s. coll., ut Rhododendron intermedium Tausch (two specimens: PRC 455631! & PRC 455632!). AUSTRIA. Ex Alp. Austr., s. d., s. coll., ut Rhododendron intermedium Tau. [sch] (originally one specimen divided onto two sheets: PRC 455629! & PRC 455630!). The first two specimens are provided with printed labels and the printed note “Tausch Dendrotheka”, while the label of the third specimen ( Fig. 1 ) has been written by Tausch himself. There is no indication about the date and collector(s) of all specimens, what is however typical for Tausch’s herbarium in general.As far as we know, Tausch never collected in the Alps and therefore he cannot be a collector of neither of specimens. Though two specimens were designated as a part of “Dendrotheca”, R. ×intermedium was never listed among 308 taxa within Tausch’s Dendrotheca exotico-bohemica issued in five fascicles ( Tausch, 1834, 1836b, 1838). This suggests that these specimens were not a part of any of the officially issued Tausch’s exsiccate collections. Indeed, we were not able to find their duplicates in other herbaria where they can be usually found (PR, W). As regards typification, there could be a problem with dating of exsiccates (versus the other authentic material) in some cases (see Kirschner et al. 2007). However, Tausch usually prepared the exsiccates before publishing the descriptions of new taxa–see his note accompanying the list of exsiccata ( Tausch 1836b: 1), and therefore we consider them to be a part of original material. With regard to the specimen collected in the Austrian Alps, we can even speculate that it could represent the original gathering of Lindacker acquired through Sieber’s collection (see above) as Tausch very often did not preserve the labels of original collector(s) but replaced them by labels prepared by himself. In this respect it is noteworthy that in the same paper where he described R. ×intermedium , he described also a new monotypic genus Rhizobotrya Tausch (1836a: 33) , one of two endemic genera to the Alps, based on Sieber’s collection where the original label was not preserved but replaced by Tausch’s label. Regardless whether or not the specimen of R. × intermedium from the Austrian Alps is Lindacker’s gathering, following Art. 9.12 ( McNeill et al. 2012), we consider this specimen to be a part of noncited original material and designate it to be a lectotype.

Figures

FIGURE 1. Lectotype of Rhododendron ×intermedium (PRC455629–left and PRC455630–right).