Diceratium prostratum Lagasca (1816: 20)

Ferrer-Gallego, P. Pablo & Laguna, Emilio, 2021, Notes on the nomenclatural types of Notoceras bicorne (Cruciferae) and its heterotypic synonyms, Phytotaxa 496 (2), pp. 195-200 : 198-199

Diceratium prostratum Lagasca (1816: 20)

The protologue of Diceratium prostratum (Lagasca 1816: 20) consists of a complete description “257. Dic. [Diceratium]. prostratum: Planta herbacea, parvula, prostrata, pilis albis, adpresis scabriusculis undique obsita. Folia lanceolata, integra, extrorsum latiora, sparsa. Spicae solitariae, extraaxillares breves; primaria radicalis. Calycis foliola iutus sub apice fornicata ut in Hemiaria. Petala lutea, exteriora duo calyce longiora subemarginata. Siliquae adpressae, pedicello brevissimo, ferè turbinato, compresso-tetragono sustentatae” followed by a name and the question mark: “¿ Erysimum bicorne . Willd. sp. pl.?”, and the provenance “Venit locis ruderatis arenoso-calcareis, Orcelis juxta Coenobium Sancti Francisci, alibique; et Murciae in tuguriorum Lazareto del Llano de la Luz dicto. D. D. Simon de Rojas Clemente eamdem plantam in Granatensi Regno offendidit”, and finally the comment “Floret toto anno”.

We have not found any original material of Lagasca in the herbaria consulted (e.g., BM, K, MA, MPU, P, SE). In the Candolle herbarium at G (collection G-DC) there are a relevant herbarium sheet, with two complete plants collected by Lagasca, with barcodes G00149933 and G00149955, with leaves and fruits. The plant with barcode G00149955 was collected by Mariano Lagasca in 1819 in Orcelis -latin ancient name of Orihuela, province of Alicante, Spain-, this plant is accompanied by a label, annotated as “n. 7 / Diceratium prostratum / Lag. Gen. et Spec. / Orceli / Lagasca 1819” and handwritten by Lagasca. On the other hand, the plant identified with barcode G00149933 is accompanied by a label, annotated as “ Diceratium prostratum / Lag. Gen. et Spec. / rota” handwritten by Lagasca, and “m. Lagasca / 1819” handwritten by Candolle. The sheet bears also a label handwritten by Candolle “ Notoceras hispanicum DC. ” ( Fig. 2 ).

Unfortunately, these two plants were collected after 1816, and therefore are post-protologue. However, the date collected in the label that accompanied the plant G00149933 was handwritten by Candolle, and not by Lagasca, and maybe this plant was used by Lagasca to describe Diceratium prostratum . Nevertheless, this hypothesis cannot be demonstrated and at the moment it cannot be considered as original material.

In conclusion, we designate as the neotype of the name Diceratium prostratum the specimen with barcode G00149955 ( Fig. 2 ). The information annotated on the label that accompanied the plant match with the protologue “Venit locis ruderatis arenoso-calcareis, Orcelis […]”, and the plant match with the current use of the name, treated in this work as a synonym of N. bicorne .

Figures

FIGURE 2. Neotype of Diceratium prostratum Lag. and Notoceras hispanicum DC. (G-DC, barcode G00149955). Photography by courtesy of Herbarium G; reproduced with permission.