Ononis tridentata subsp. arbuscula (Desvaux) P.P. Ferrer

Ferrer-Gallego, P. Pablo, 2023, Original elemets and typification of the names included in the Ononis tridentata complex (Fabaceae), Phytotaxa 598 (1), pp. 32-58 : 38-40

Ononis tridentata subsp. arbuscula (Desvaux) P.P. Ferrer

As mentioned above, due to the epitype designation for the name Ononis tridentata published by F̂rther (in Turland & Jarvis 1997: 478), a new name in subspecies rank should be proposed for the Iberian populations that until now were known with the traditional concept (pre-epitypification) of O. tridentata subsp. tridentata .

In this sense, there is a relevant early name published by Desvaux (1814: 76), Ononis arbuscula (see Losa 1958, Devesa & López González 1997). Nicaise Auguste Desvaux (1784-1856) was a French botanist at Angers ( France). He was appointed director of the Angers botanic garden in 1817. Desvaux did not personally collect botanical specimens beyond the region of Angers. He received specimens from many correspondents, but the collector is not noted and the area stated is rarely specific ( Howard et al. 1981). In his Journal de Botanique Appliquée Desvaux proposed a large number of species. It would not be true to say that his work was neglected; but it was difficult to follow. His descriptions, though accurate as far as they go, are brief and, like so many older ones, omit details later deemed essential. His data of locality are frequently very general and by no means always correct. He never cited collectors; authentic material, where it exists, has been, therefore, hard to identify as such. Until 1896, when it was presented to the Museum d’Histoire Naturelle at Paris, his personal herbarium remained in the possession of his family, presumably more or less inaccesible ( Weatherby 1936). Following Desvaux’s death in 1856, his general herbarium was sold by his son to Alphonse Lavallée ( Bureau 1896, Bonnet 1907). Lavallée moved the collection to Segrez (Seine-et-Oise). It was given to the Museum of Natural History, Paris, by his widow in 1896 ( Bureau 1896). The collection has been subsequently integrated into the general herbarium ( Howard et al. 1981). Several types are preserved at P, P-JU, and PC, other material is kept at B (Willdenow), FI, G, and M (Stafleu & Cowan 1976).

An unusually large proportion of Desvaux’s species have been misunderstood or left as frankly doubtful. One of these species could be Ononis arbuscula . The identity of this name has long been controversial, it could not be assigned with confidence to any known member of the group due to the ambiguity of the name and the ensuing nomenclatural confusion and uncertainty among users (see Devesa & López González 1997). One option would have been to reject this troublesome name altogether. However, a precise typification would allow the use of the name Ononis arbuscula .

The protologue of Ononis arbuscula Desvaux (1814: 76) includes a description in Latin “Caule fruticoso racemis infra tuberculosis, apicè tomentosis; foliis crassis glabris subspathulatis apicè dentatis; calicibus sub-glabris; leguminibus solitariis pedunculatis hirsutis” followed by the geographical provenance “Habitât in Europeâ australis”.

In the Willdenow herbarium at B there is a specimen of Ononis tridentata . The sheet, with barcode B -W 13318 -00 0, bears six poorly preserved plant fragments plant of this species, and is annotated “ On. tridentata / 1.” at the top of the sheet, and “Roestel. W.” at the base of the sheet. The sheet also bears an original label handwritten by Willdenow “Diadelphia Decandria / Ononis tridentata fruticosa, / foliis ternatis cyanosis sub-/ linearibus tridentatis, pedun-/ culis bifloris Lin. Sp. Pl. ed R3. p. 431. / Habitat in Hispania ” (image available at https://herbarium.bgbm.org/ object/BW13318000). However, due to the absence of original annotations by Desvaux explicitly linked to his Ononis arbuscula in the sheet at B and according to Art. 9.4 (a) of the Shenzhen Code ( Turland et al. 2018), this specimen cannot be considered original material.

Fortunately, there is a herbarium sheet at P, with barcode P03447770 that bear original material of Desvaux of Ononis arbuscula . This sheet bears three stems, with leaves, flowers and fruits, and five labels. The stem mounted on the right half of the herbarium sheet is labeled as “On[onis] tridentara / Ononis tridentata / Cav. / en Hispania / prope Granatam. This specimen can be identified as belonging to O. tridentata subsp. crassifolia . The stem mounted on the center of the sheet is labeled as “ Ononis arbuscula Desv. ”. The stem mounted on the left half of the sheet is accompanied by two handwritten labels by Desvaux, annotated as: 1) Ononis tridentata L. Cav. ic. / 2. t. 152 / - arbuscula Desv. J. Bot. 1814 / 1 p. 76 / Mag. hort. t. 16 / hab. in Hispania ”, and 2) “Spec. nova / hab. Hisp.”. The sheet also bears a printed label “Herb. Mus. Paris / Herbier de A. N. Desvaux / Donné par Mme Vve Lavallée en 1896” ( Fig. 5 ). Among these three stems, I designate as the lectotype of the name Ononis arbuscula the stem mounted on the left half of the sheet, which bears two original labels handwritten by Desvaux. This specimen shows important diagnostic features (leaflets blade lanceolate-cuneate, less than six times longer than wider, with (0–)3(–5) teeth in the upper half, inflorescence most times 1–2-flowered, axillary; indumenta only of short glandular hairs) and matches both the historical and current concepts of this taxon (until now named under O. tridentata subsp. tridentata ) (see e.g., see Devesa & López González 1997, Devesa 2000, 2009, López González 2001, Mota et al. 2011, Agulló et al. 2013).

Ononis tridentata s.l. includes several names validly published as nomenclatural and taxonomic synonyms, and the typification of the most relevant names is necessary for their correct application in this taxonomically difficult group. In this sense, the names O. barrelieri , O. crassifolia var. intricata , O. tridentata var. canescens , O. tridentata f. intermedia , and O. tridentata var. intermedia f. erecta should be treated as synonyms of O. tridentata subsp. arbuscula , comb. & stat nov., and not as synonyms of O. tridentata Linnaeus s.str. due to the epitype of this name designated by F̂rther in 1997.

Figures

FIGURE 5. Lectotype of Ononis tridentata subsp. arbuscula (Desvaux) P.P. Ferrer, P (barcode P03447770 [the lectotype is the stem mounted on the left half of the sheet, accompanied by two labels handwritten by Desvaux]). Image courtesy of the herbarium P, reproduced with permission.