Myrcia melastomoides De Candolle (1828: 256)

Santos, Matheus F., Amorim, Bruno S., Burton, George P., Faria, Jair E. Q., Fernandes, Thiago, Flickinger, Jonathan A., Gaem, Paulo Henrique, Landrum, Leslie R., Lima, Duane F., Proença, Carolyn E. B., Rosa, Priscila O., Lima-Dos-Santos, Leidiana, Setubal, Robberson B., Stadnik, Aline M. S., Staggemeier, Vanessa G., Vasconcelos, Thais N. C. & Lucas, Eve J., 2024, A taxonomic account of Myrciinae (Myrteae, Myrtaceae): generic and sectional placement of forgotten species and a list of all accepted species, Phytotaxa 674 (2), pp. 129-170 : 131-132

1.1. Myrcia melastomoides De Candolle (1828: 256) . Type :— TOBAGO? [ANTILLES]. unknown date, unknown collector (lectotype G-DC [G00661605, QR03] [image!] designated here; isolectotypes G-DC [G00661605, QR01] [image!], G-DC [G00661605, QR02] [image!]) .

De Candolle (1828: 256) suggested the origin of the material of Myrcia melastomoides as Trinidad and Tobago, but the label present in the specimens cites “Antilles” as a generic location. The German botanist Ignatz Urban (in April of 1894, and also in Urban 1894 –1895) and one of us (EJL in 2005) made annotations on the type collection stating that it was not Myrtaceae and suggested Melastomataceae . The type specimens of M. melastomoides has acrodromous, 3-plinerved leaf venation not exclusive to Melastomataceae , a character that is also found in other groups such as Strychnos Linnaeus (1753: 189) from Loganiaceae , with ca. 80 species in the Neotropics ( Setubal et al. 2021). The type material has other features similar to Strychnos such as an interpetiolar line (very thin in this case) and a panicle-like inflorescence. However, M. melastomoides lacks other important diagnostic characters of Strychnos such as: nodes conspicuous by thickened and woody petiole bases that support axillary branches after the leaves have fallen (vs. nodes not thickened and the bases of the petioles attached to the fallen leaves leaving circular scars in the twigs) and branches usually with tendrils or other innovations typical of the lianescent species of Strychnos (vs. tendrils absent) ( Setubal et al. 2021). Furthermore, the subsessile leaves, the axillary inflorescences with long internodes and the small fruits, ca. 0.5 cm in diameter, with thin and smooth pericarp present in M. melastomoides are incompatible with other species of Strychnos with axillary inflorescences that occur in the Caribbean and nearby continental regions. For these reasons, the species remains in Myrcia as it is the only available name. However, it is not a Myrcia and phylogenetic analyses are desirable to establish relationships of this species.

The cited gathering is composed of three sheets, and we choose the sheet that bears De Candolle’s annotation as the lectotype.