Rhamnus myrtifolia Willkomm (1852: 18)

Ferrer-Gallego, P. Pablo & Laguna, Emilio, 2017, Remarks on the type designation of two names in Rhamnus (Rhamnaceae), Phytotaxa 302 (3), pp. 279-284 : 280-282

Rhamnus myrtifolia Willkomm (1852: 18) [“ myrtifolius ”]

Type (lectotype, designated here):—[ SPAIN]. In fissuris rupium regionis montanae: in Sierra Nevada prope Cortijo de S. Gerónimo saxa dense obducens, 8000ˈ, 1 August 1844, H. M. Willkomm nº 241, COI (barcode COI 00064364) [specimen on the lower left of the sheet] (Image available at http://sequoia.bot.uc.pt/herbario/catalogue/index.php?t=results_specimen&genus=rhamnus&species=m yrtifolia&CollectionID=6&page=0). Isolectotype: G (barcode G 00440967) (image available at http://www.ville-ge.ch/musinfo/bd/ cjb/chg/adetail.php?id=308178&lang=en).

The protologue of Rh. myrtifolia includes two publication citations “ Rh. Alaternus var. prostrata Boiss. l. c. [Voyage botanique dans le midi de l’Espagne, 1840] p. 128” (see Boissier 1840: 128) and “ Rh. infectorius var. Kunze in Flora 1846. p. 650. non L.” (see Kunze 1846: 650), followed by the indication of a gathering “Pl. exs. a. 1844. n. 241” [241 is the number species of Rh. infectorius L. in Kunze’s work (see http://www.biodiversitylibrary.org/item/943#page/653/mode/1up)] and the paragraph “Hab. in fissuris rupium regionis montanae et alpinae (3000–8000ˈ) regni Granatensis: in Serrania de Ronda, Sierra Tejeda, Sierra Nevada, ubi cl. Boissier hanc speciem detexit. Lisdem locis ego aestate 1844 et 1845 eam cum fructibus legi.” Willkomm (1852: 18–19). The protologue also includes a complete diagnosis.

Willkomm explicitly cited a gathering in the protologue “Pl. exs. a. 1844. n. 241”, and at COI there is a specimen with this number “241” collected in August 1844 by Willkomm “In fissuris rupium regionis montanae: in Sierra Nevada prope Cortijo de S. Gerónimo saxa dense obducens, 8000ˈ, 1 August 1844 ” ( COI, barcode COI 00064364 [specimen on the lower left of the sheet]) (image available at http://sequoia.bot.uc.pt/herbario/catalogue/index.php?t=results_specim en&genus=rhamnus&species =myrtifolia &CollectionID=6&page=0). Therefore this specimen is a syntype according to Art. 9.5 of the ICN.

On the other hand, Rivas-Martínez & Pizarro (2011: 65) indicate that the “ lectotype ” of this name corresponds to a specimen collected by Willkomm in June 1845 “in fissuris rupium calcarearum prope pagum Canillas de Aceytuno ad radices montis Sierra Tejeda, prope monasterium”, and the specimen is preserved in the same sheet at COI (specimen on the lower right part of the sheet), but without collecting number, and with barcode COI 00064365 (image available at http://sequoia.bot.uc.pt/herbario/catalogue/index.php?&t=results_specimen&genus=rhamnus&species =myrtifolia &CollectionID=6&page=1).

Willkomm indicates in his protologue a gathering “Pl. [Plantae] exs. [exsiccatae] a [anno]. 1844. n. [numero] 241” and he also states “… Lisdem locis ego aestate 1844 et 1845 eam cum fructibus legi.” (“In summer 1844 and 1845, I collected this with fruits from the same locality”). This means that fruiting specimens collected in 1844 and 1845 (presumably without collecting number) were used by Willkomm to complete his description of the plant. Therefore, the specimen collected in 1845 and preserved with barcode COI 00064365 is also a syntype (see Art. 40 Note 2 of the ICN).

In the same sheet at COI, with barcode COI 00064366 (specimen on the top of the sheet), there is preserved other fragment of Rh. myrtifolia , with leaves and fruits, collected by Michael Funk in 1848, and is annotated “ Rh. alaternus L. var. prostratus B. [Boissier] / In den Felsenritzen der Peñon de San Francisco / 1848-7-Aug [August]” ( Spain, Granada, Sierra Nevada) (image available at http://sequoia.bot.uc.pt/herbario/catalogue/index.php?t=results_specim en&genus=rhamnus&CatalogNumber= COI 00064366&CollectionID=6&orderby=relevance&orderdirection= DES C &size=10&page=0). However, this material (with barcode COI 00064366) was not explicitly cited in the protologue and so, it cannot be considered as syntype. Additionally due to the absence of original annotations by Willkomm explicitly linked to Rh. myrtifolia in the sheet, this specimen probably cannot be considered original material (see Art. 9.3 (a) ).

Finally, in the herbarium at G there is a sheet, with barcode G 00440967, that bears a fragment of Rh. myrtifolia , with leaves and fruits, and two labels: 1) “1. Rh. alaternus L. / v. prostratus Boiss. ”, and 2) “241. Rhamnus infectoria L. / S. Nevada [impress] / Willkomm / 1847 [manuscript]” (image available at http://www.ville-ge.ch/musinfo/ bd/cjb/chg/adetail.php?id=308178&lang=en). The G specimen is very similar to the COI specimen (with barcode COI 00064364, and numbered “241”), however no collecting date is indicated, and only is annotated the collecting number on the printed label “241”. The annotation on the label “Willkomm 1847” most likely refers to the date specimen was received in Geneva, not the collection date. In this sense, the first Willkomm’s exploration in Iberian Peninsula was between 1844 and 1846, and a second one in 1850 ( Devesa & Viera 2001). Thus, in our opinion this specimen can be considered as a duplicate of the specimen at COI 00064364, and therefore also a syntype. We have been unable to trace further original material in other herbaria (see herbaria in Stafleu & Cowan 1988: 336).

Among the mentioned syntypes at COI and G, the specimen at COI, with barcode COI 00064364, is the best choice for lectotype of the name Rhamnus myrtifolia , since it is the most complete and the best representative original material available. This specimen agrees with the traditional concept and current use of the name of this species (e.g., Rivas-Martínez & Pizarro 2011, 2013).