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| Paepalanthus oreodoxus Andrino & Gonella in Andrino & Gonella, 2021. |
Abstract
Background and aims – Recent botanical discoveries have highlighted the occurrence of campos rupestres in the Serra do Padre Ângelo (SPA), eastern Minas Gerais, Brazil. Here, we introduce the first new species of Paepalanthus subg. Xeractis to be described in the last three decades. Discovered in the SPA, it belongs to an emblematic lineage endemic to the campos rupestres of Minas Gerais.
Material and methods – The new species is described based on herbarium material and in situ observations. A morphological phylogenetic analysis was carried out by including the new species in a previously published character matrix. Its spatial distribution is discussed based on the obtained topology.
Key results – The new species is endemic to the SPA, but its closest related taxa are endemic to the Espinhaço Range (ER), ca 200 km distant. Its placement in the phylogeny supports the inclusion in P. ser. Fuscati, representing an escape from the ER. We present a clear morphological differentiation between the new species and its closest related taxa. Other similar cases of disjunct distribution among these areas of campos rupestres (SPA vs ER) are reviewed and discussed.
Conclusion – Based on the restricted distribution, allied with threats to the habitat, the new species is inserted in the IUCN category of Critically Endangered (CR). This new discovery reinforces the singularity of the SPA and the relevance of biodiversity inventories and conservation studies in the easternmost campos rupestres, and their classification as a priority area for conservation.
Keywords: Atlantic Forest; Campos Rupestres; Critically Endangered; Disjunction; Paepalanthus oreodoxus; Serra do Padre Ângelo
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| Figure 2: Paepalanthus oreodoxus Andrino & Gonella (based on Gonella et al. 1044). A. Habit. B. Capitulum detail, side view. C. Capitulum detail showing hygroscopic involucral bracts. D. Involucral bracts, abaxial surface, external series on the left side and internal ones on the right. E. Staminate flower with the floral bract. F. Staminate flower with sepals removed and open corolla. G. Floral bract. H. Pistilate flower. I. Petal of pistilate flower, adaxial surface. J. Gynoecium. K. Seed. Illustration by João Silveira. |
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| Figure 3: A. View of the campos rupestres on the top of Pico do Padre Ângelo, habitat of Paepalanthus oreodoxus, with Pico do Sossego and Pico do Pinhão in the background. B. Paepalanthus oreodoxus among rocks. C. Exceptionally long specimen of P. oreodoxus growing pendulous in a shaded area with one of the authors for scale. D. Immature capitulum in dry weather, showing recurved involucral bracts. E. Side view of the capitulum with bracts opening after a wet night. F. Capitulum with hygroscopically bent bracts over the flower disc in wet weather. G. Capitula with recurved bracts in dry weather. H. Front view of capitula, showing the long involucral bracts characteristic of the species. I. Staminate flower with anthers cream-coloured with dark pigmentation in the dorsal portion. A, D, F-H by Paulo M. Gonella; C by Danilo Pacheco Cordeiro; B, E, I by Andreas Fleischmann. |
Paepalanthus oreodoxus Andrino & Gonella, sp. nov.
Diagnosis – The new species is morphologically most similar to Paepalanthus mollis Kunth, but differs in the stem branches loosely arranged (vs densely arranged in compact clumps), well-developed, longer and erect (rarely pendulous) stem 8–40(–230) cm long (vs decumbent and inconspicuous stem, rarely up to 12 cm long), leaves laxly arranged along the stem with conspicuous internodes (vs congested in a rosette with inconspicuous internodes), old stems with persistent dead leaves (vs caducous leaves on plants with elongated stems), scapes 3-costate (vs 4–5-costate), involucral bracts of the internal series narrower (0.7–2.2 mm wide vs 2.1–4.1 mm wide) and surpassing the floral disc in 4 to 6 mm (vs 1.5 to 4.5 mm), anthers dorsally brown and cream-coloured in the ventral portion (vs dark brown to light yellow brown), and floral bracts narrowly spatulate to subulate (vs linear to lance-linear or spatulate).
Etymology – From the Greek oreo “pertaining to mountains” and doxa “glory”. This epithet was chosen as this gracious new species is exclusively found on the mountaintops of a recently discovered area of campos rupestres, representing an outstanding discovery that reinforces the singularity of the SPA flora and the importance of its conservation.
Caroline Oliveira Andrino and Paulo Gonella. 2021. An Escape from the Espinhaço Range: A New Species of Paepalanthus subg. Xeractis (Eriocaulaceae) from the campos rupestres of Serra do Padre Ângelo, Minas Gerais, Brazil. Plant Ecology and Evolution. 154(1); 137-149. DOI: 10.5091/plecevo.2021.1770
