Paepalanthus politus Trovó

Trovó, Marcelo & Echternacht, Lívia, 2022, The Paepalanthoideae (Eriocaulaceae) of the Chapada dos Veadeiros National Park, Brazil: taxonomic novelties, identification key, and illustrated list of species, European Journal of Taxonomy 834, pp. 58-93 : 69

Paepalanthus politus Trovó stat. et nom. nov.

Fig. 8D

Paepalanthus elongatus var. glabrescens Moldenke. Phytologia 43: 196 ( Moldenke 1979).

Material examined

Type BRAZIL • Goiás, Campo arenoso úmido; rodovia GO-12, Km 5–10 ao sul de Alto Paraíso – Goiás; 24 May 1975; G. Hatschbach 36772; holotype: US [ US00088344 ]; isotypes: MO [ MO1430138 ], UPCB .

Notes

Moldenke (1979) briefly described Paepalanthus elongatus var. glabrescens based on a single collection (G. Hatschbach 36772), distinguished from the typical variety solely by its narrow leaves and glabrous or subglabrous spathes. Trovó (2018) considered such character states as within the morphological variation of Paepalanthus elongatus var. elongatus and proposed its synonymization. Trovó (2018) also commented that two isotypes (G. Hatschbach 36772 MO, UPCB) were annotated by Moldenke himself in 1975 as Paepalanthus elongatus var. angustifolius Silveira , enhancing the fragile delimitation of such taxa. Herbarized specimens of P. politus are indeed tricky to distinguish from the bulk of the P. elongatus species complex and may explain such nomenclatural instability.

During our field trips, we located a single population in the Rio Preto Valley of what we first thought to be a new species. When analyzing the dried specimens for this manuscript, it became clear that such specimens belong to the taxon described by Moldenke (1979) as Paepalanthus elongatus var. glabrescens . It is, however, much different from Paepalanthus elongatus var. elongatus due not only to the characters pointed out by Moldenke (1979), but mainly by its bright and completely glabrous involucral bracts slightly surpassing the floral disc (vs opaque and pilose, densely ciliated involucral bracts largely surpassing the floral disc). The position, the apex, and the color of the involucral bracts are also noteworthy and different. In P. politus , the bracts of all series are patent; with an acute apex; and with a paleaceous central stripe, while in P. elongatus var. elongatus the inner bracts are recurved; all bracts have a long acuminate apex; with a dark castaneous central stripe. The taxon deserves thus the species status with a new name, as the epithet “ glabrescens ” is already taken ( Hensold 2017). The epithet “ politus ” is related to the shiny involucral bracts, with a polished aspect. A complete description of the species will be available in a forthcoming revision of Paepalanthus ser. Dimeri (Ruhland) Giul.

Figures

Fig. 8. Species of Paepalanthoideae (Eriocaulaceae) from the Chapada dos Veadeiros National Park. A. Paepalanthus macer Trovó. B. P. modestus Trovó. C. P. niger (Moldenke) Trovó. D. P. politus Trovó stat. et nom. nov. E. P. polytrichoides Kunth. F. P. scandens Ruhland. G. P. sphaerocephalus Ruhland. H. P. stellatus Trovó.