Ludwigia myrtifolia (Camb.) Hara., 1953

Funez, Luís Adriano, Farias, David Moura, Gasper, André Luís De & Hassemer, Gustavo, 2021, Ludwigia irregularis (Onagraceae) a rare new species from southern Brazil, and typification of the morphologically similar L. myrtifolia, Phytotaxa 520 (3), pp. 257-264 : 262

Ludwigia myrtifolia (Camb.) Hara. Figure 3 .

≡ Jussiaea myrtifolia Cambessèdes (1829: 260–261) .

Type: — BRAZIL. Minas Gerais: 1816–1821, A. F. C. P. de Saint-Hilaire B1-1532 (lectotype [designated here] P barcode P01819487 !; isolectotypes MPU barcode MPU011204 !, P barcode P01819488 !) .

Diagnosis: —Differ from Ludwigia martii by the narrow lanceolate leaves, 1–4 × 0.2–1 cm vs. ovate leaves, 3–9 × 0.5–2.2 cm, and from L. irwinii by the leaves 1–4 cm long vs. 4–9.5 cm long.

Illustrations: —Plate 132 in Cambessèdes (1829); Figure 29 in Ramamoorthy & Zardini (1987).

Nomenclatural notes: —The protologue of Jussiaea myrtifolia ( Cambessèdes 1829: 260–261) states that the species was collected “ In sabulosis ad flumen Jiquitinhonha in parte provinciae Minas Geraës dictâ Minas Novas ”, that is, “in marsh along river Jequitinhonha in the part of the province of Minas Gerais named Minas Novas”. No additional information regarding the type was provided in Hara (1953), while Ramamoorthy & Zardini (1987: 62), state the following: “Type: Brazil. Minas Gerais: Rio Jequitinhonha, May–June 1817, Saint-Hilaire B1. 1532 (holotype, P)”. The “ holotype ” indication is an error to be automatically corrected to a lectotypification (Art. 9.10 of the Code), because two specimens of the gathering A.F.C.P. de Saint-Hilaire B1-1532 are kept at P (barcodes P01819487 and P01819488). This typification must be narrowed to a single specimen by way of a subsequent lectotypification (Art. 9.17 of the Code). One of the two specimens at P, viz. barcode P01819487, has a label on it left by Thennilapuram Parasuraman Ramamoorthy in 1978, annotated (presumably by him) “ TYPE ”. Nevertheless, this handwritten type indication is not effective, because the designation of a type is achieved only by effective publication (Art. 7.10 of the Code). All things considered, we designate here the specimen P barcode P01819487 as lectotype of the name J. myrtifolia . A further isolectotype is kept at MPU (barcode MPU011204).

Figures

FIGURE 3. Lectotype of Ludwigia myrtifolia (A.F.C.P. de Saint-Hilaire B1-1532 P barcode P01819487). Copyright: Muséum National d’Histoire Naturelle.