Porina epiphylla

Porina cf. epiphylla 1 & 2 Fée, Essai Crypt. Exot. (Paris): 76. 1825 [1824]. Fig. 14 A, B Type. FRENCH GUIANA • Leprieur (lectotype: PC, designated by Santesson (1952: 234)). Notes. Porina epiphylla is a common and widely distributed tropical species (Lücking 2008). It has been reported in Madagascar by Aptroot (2016) and in Mauritius by Ertz and Diederich (2022). Porina cf. epiphylla 1 (Fig. 14 A) is represented by specimen 20274 D from northern Madagascar, whereas P. cf. epiphylla 2 (Fig. 14 B) is represented by specimen 24006 A from Mauritius. Both specimens broadly match the published concept of P. epiphylla (Lücking and Vězda 1998; Lücking 2008), possessing a continuous, marginally dispersed, and minutely uneven thallus and lens-shaped to hemispherical perithecia with a slight reddish tinge. The reported 7 - septate ascospores, measuring 26–33 × 3–4 µm, and perithecia, measuring 0.25–0.45 mm, are largely consistent with the examined specimens. In P. cf. epiphylla 1, ascospores measure (25.5 –) 27–32 (– 35.5) × (3.1 –) 3.4–4.4 (– 5.1) µm (n = 32) and perithecia 0.4–0.45 mm (n = 11), whereas in P. cf. epiphylla 2 the ascospores measure (26 –) 30–34 (– 36) × (4.2 –) 4.5–5.4 (– 6.5) µm (n = 45) and perithecia measure 0.4–0.45 mm (n = 10). Despite their overall similarity, each specimen departs slightly from the published concept of P. epiphylla. Porina cf. epiphylla 1 appears to possess a very thin, almost translucent thallus, a feature not observed in the examined specimens from the Phylloporina clade. Meanwhile, P. cf. epiphylla 2 has slightly longer and broader ascospores. In the ITS and mtSSU phylogenies, the sequences from the two specimens do not cluster together; instead, they form two distinct lineages within the Phylloporina clade (Figs 2, 3). Porina cf. epiphylla 1 is recovered in the Paleotropical P. epiphylla - P. lucida subclade, whereas P. cf. epiphylla 2 is recovered outside of this group. Neither mtSSU sequence clusters with the Neotropical accessions of P. epiphylla, the region where the species was described, suggesting that these specimens might represent taxa distinct from P. epiphylla s. str. Interestingly, two independently extracted neighbouring thallus fragments of P. cf. epiphylla 2 yielded different but closely related mtSSU sequences. Neither of the amplified products showed any clear sign of contamination. Porina cf. epiphylla 2 was associated exclusively with algal haplotype 26: 9, whereas P. cf. epiphylla 1 was associated with two algal haplotypes (26: 1 and 26: 6) (Figs 4, 5). Overall, the available evidence indicates that the two specimens represent distinct Paleotropical lineages that broadly resemble the current morphological concept of P. epiphylla but cannot be confidently assigned to P. epiphylla s. str. in the absence of type-linked molecular data. They are therefore retained as P. cf. epiphylla 1 and P. cf. epiphylla 2. Specimens examined. MADAGASCAR – Diego Suarez Prov. • Antsiranana, Region: Diana, District: Diego II, Commune: Joffreville, Forontany: Morafeu, National Park of Montagne d’Ambre, along trail from summit Olioly to small dam near camp Gîte des Roussettes, through moist montane forest, 12°32'34"S, 49°09'23"E, alt. 1242 m, 8 Oct. 2014, Ertz 20274 D (BR, TAN). – MAURITIUS – Rivière Noire District • Black River Gorges National Park, along trail from Plaine Champagne towards Piton de la Petite Rivière Noire, 20°24'52"S (ca. 1000 m), 57°24'43"E (ca. 500 m), alt. 630–800 m, dense evergreen mountainous forest, 07 Sep. 2019; Ertz 24006 A (BR).