Ronnbergia aciculosa (Mez & Sodiro) Aguirre-Santoro
Taxonomic Change:
Literature references:
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Comments:
- Ronnbergia aciculosa (Mez & Sodiro) Aguirre- Santoro. Pl. Syst. Evol. 303: 625 (2017). Aguirre-Santoro (2017) commented on the problematic taxonomic concept of Ronnbergia aciculosa because its holotype does not exhibit the long mucro of the floral bracts (10 mm long); a supposedly diagnostic feature of the species described in the protologue. Because of this ambiguity, many specimens of R. tonduzii (Mez & Pittier) Aguirre-Santoro in different herbaria have been doubtfully identified as R. aciculosa based solely on the presence of a slightly long sepal mucro (ca. 2 mm), which is normally very short in R. tonduzii (0.5–1.5 mm long). Recently, the herbarium QPLS uploaded an image to JStor (https://plants.jstor.org/) of the isotype of R. aciculosa (Sodiro 171/2). This specimen is in much better condition than the holotype deposited in the herbarium B (herbarium of the Botanic Garden and Botanical Museum Berlin-Dahlem) and permits a much better characterization of its morphology. A detailed comparison of the type specimen of R. aciculosa from QPLS with the type specimen of R. tonduzii shows that the former species can be differentiated from R. tonduzii by its linear-triangular floral bracts (vs. ovate), bearing a 2–3 mm mucro (vs. —See Aguirre-Santoro & Betancur 2021 p. 10