Ximenesia encelioides Cavanilles (1793: 60)

Crespo, Manuel B. & Alonso, Ángeles, 2016, Remarks and clarifications on the type material of Ximenesia encelioides (Verbesina encelioides; Asteraceae, Heliantheae), with a new lectotype designation, Phytotaxa 253 (2), pp. 161-165 : 161-164

Ximenesia encelioides Cavanilles (1793: 60) [sphalm. “ enceloides ”]

≡ Verbesina encelioides (Cav.) Benth. & Hook. f. ex Gray (1876: 350)

Ind. loc.:—“Habitat in Mexico, unde introducta in Regium hortum Matritensem”.

Lectotype (designated here):—[icon] Cavanilles (1793: tab. 178), “ Ximenesia encelioides ” ( Fig. 1 ).

Notes:—It is worth mentioning that contrarily to argumentation by Hind (2011) and according to Art. 46.5 Ex. 29 of the ICN, the full authority of the combination Verbesina encelioides should be cited “Benth. & Hook.f. ex A.Gray”, as currently shown in IPNI (2016).

Cavanilles’s material at MA was first housed among the historical collections (“ Antiquum generale Herbarium ”), and later placed in the collection “ Typi Cavanillesianum ” (http://herbario.rjb.csic.es/). Those materials were manually numbered in 1990, and later digitalised and barcoded in August 2009 (Noya pers. comm.).

In a study of Cavanilles’s historical collections at MA, Garilleti (1993) remarked that part of the material in the voucher MA-00476508!, which then included two unmarked sheets, should correspond to the gathering indicated in the protologue, and therefore should be considered original material. However, as a result of recent digitalisation, both sheets are currently barcoded MA-00476508 and MA-00476508–2 ( Fig. 2 ), a sequence that is opposite to that of Garilleti (1993) (see additional details in Juan et al. 2015). Other two additional vouchers of Ximenesia encelioides Cav. also conserved among the Cavanillesian types at Madrid (MA barcodes MA-00476509! and MA-00476510!; images available at http://herbario. rjb.csic.es/imagenes2/basesdedatos.html) are not relevant for typification since they were collected after publication of that name in 1793, though bring interesting data for lectotype designation as shown below.

In the protologue of X. encelioides, Cavanilles (1793) did not cite either holotype or syntypes. Therefore the original material of that name, from which a new lectotype should be designated, is constituted by the illustration in “Tab. 178” ( Fig. 1 ) and some of the fragments in the sheets kept in MA currently barcoded MA-00476508 and MA-00476508–2 ( Fig. 2 ).

As correctly described in Juan et al. (2015), those two sheets at MA include material collected in the flowerbeds of Real Jardín Botánico de Madrid at three different times. On the one hand, MA-00476508 ( Fig. 2A ) includes six fragments but does not bear any original label, it showing only two modern typewritten labels referring to the Cavanillesian type locality. On the other hand, MA-00476508–2 ( Fig. 2B ) shows four fragments and several labels with data useful for lectotype selection. Two of them are identical to the labels on the voucher MA-00476509 and were handwritten in 1801 and 1841 by José Demetrio Rodríguez, a disciple of Cavanilles. Another label is in Cavanilles’s hand and matches the information in the protologue. Unfortunately, none of those three labels is clearly connected to the corresponding plant fragments, a fact that hinders the unequivocal identification of the true Cavanillesian gathering.

Joining several successive gatherings of the same type plant in a single voucher appears to be a common practice in the 19 th century in MA, perhaps due to the scarcity of paper and/or space in the herbarium. This fact sometimes makes difficult identification of original material of plants collected in the Spanish expeditions around the New World (see, for instance, Crespo & Pena-Martín 2014).

Although today it is not possible to trace the real source and collection date of the fragments in that “ lectotype ” sheet, most of them (as well as those in MA-00476509) appear to belong to descendants of the individuals grown in Madrid and described by Cavanilles (or even some of these were “clonotypes”), and they are relevant to the authentic material. Furthermore, all specimens in those vouchers are in good state or conservation and are undoubtedly identifiable with the current Verbesina encelioides , and hence the application of the name is not threatened.

A detailed comparison of the illustration in the protologue ( Fig. 1 ) with every single fragment in MA-00476508 and MA-00476508–2 does not bring a perfect match, which will facilitate lectotypification. However, part of the fragment in the lower central side of MA-00476508 or the one on the left side of that sheet are partially very similar to Cavanilles’s drawing, the former also bearing fruiting heads that could have served for preparing “Tab. 178”. These facts would probably suggest that Cavanilles’s artwork either was drawn from fragments that were discarded later or would represent only part or parts of the fragments in the original material.

As the vouchers MA-00476508 and MA-00476508–2 include fragments from three different gatherings, designation of any of them as lectotype would be speculative and even daring, since no connection with the corresponding labels and collection dates can be unmistakably established. It is worth mentioning here that both biggest fragments in the central and left lower sides of MA-00476508–2, which were suggested as good candidates for lectotype by Juan et al. (2005), look very much alike the biggest fragments on MA-00476509. Those latter were collected either in 1801 or 1841, and therefore they most probably belong to gatherings made after publication of the protologue. Any of the remaining two fragments in MA-00476508–2 can neither be undoubtedly identified as belonging to the 1792 gathering.

Accordingly, it is safer in this case to designate the illustration in “Tab. 178” as lectotype of the name Ximenesia encelioides . This avoids involuntary selection of a fragment not corresponding with Cavanilles’s original gathering, and hence not belonging to the original material.

It should be noted that the drawing of X. encelioides here designated as lectotype is incomplete (it depicts the upper part of a stem, lacking the typically opposite lower leaves) and some of the diagnostic features it shows are poor (e.g. lack of leaf indumentum details, unclear structure of capitula, or undetailed features of flowers and fruits). However, the general habit and the structures depicted allow an easy and unambiguous identification of the species as well as a precise application of the name, and therefore an eventual epitype designation is not necessary as required by Art. 9.8 of the ICN.

Figures

FIGURE 1. Ximenesia encelioides Cav. [Verbesina encelioides (Cav.) Benth.& Hook.f. exA.Gray]. Illustration in the protologue (as “Tab. 178”), designated here as lectotype of the name. Reproduced with permission (Biblioteca del Real Jardín Botánico, CSIC, Madrid).

FIGURE 2.Part of the probable original material of Ximenesia encelioides Cav.[Verbesinaencelioides (Cav.) Benth.&Hook.f.exA.Gray], including three different gatherings. A. Voucher MA-00476508! with material lacking original labels; B. Voucher MA-00476508−2! which bears the historical label handwritten by Cavanilles, among others. Reproduced with permission (Herbario del Real Jardín Botánico, CSIC, Madrid).