Porina karnatakensis

Porina cf. karnatakensis 1 & 2 Makhija, Adaw. & Patw., J. Econ. Taxon. Bot. 18 (3): 538. 1995 [1994]. Fig. 15 C, D Type. INDIA • Karnataka: Londha to Yellapur road, Patwardhan and Prabhu 74.3642 (holotype: AMH). Notes. New record for Madagascar and Mayotte. Porina karnatakensis is a widely distributed pantropical species found in the shaded rainforest understories to dry evergreen forests (Lücking 2008). Porina cf. karnatakensis 1 (Fig. 15 C) is represented by two specimens from Mayotte (22135 B and 22135 E), whereas P. cf. karnatakensis 2 (Fig. 15 D) comprises three specimens from northern and southern Madagascar (20276 J, 25303 G, and 25374 C). The specimens closely match the current concept of P. karnatakensis, a species also described as Porina atropunctata Lücking & Vězda, which was subsequently synonymised with P. karnatakensis by Lücking and Kalb (2002). However, the original description of P. karnatakensis by Makhija et al. (1994) differs substantially from that of P. atropunctata by Lücking and Vězda (1998). In the original description, P. karnatakensis is described as having 7 - to 9 - septate ascospores, measuring 33–63 × 4 µm, whereas P. atropunctata has 7 - septate ascospores, measuring (20 –) 25–32 (– 35) × 3–5 μm. Therefore, the description of P. karnatakensis in Lücking (2008), likely based on P. atropunctata material, is used here for comparison. Examined specimens possess 7 - septate ascospores consistent with that description. In P. cf. karnatakensis 1, the ascospores measure (23 –) 26–34 (– 38) × (2.5 –) 2.8–3.7 (– 4.2) µm (n = 32), whereas those of P. cf. karnatakensis 2 measure (24.5 –) 26.5–30.5 (– 34) × (3 –) 3.3–3.9 (– 4.2) µm (n = 73), both agreeing well with the reported dimensions of (20 –) 25–35 × 3–5 µm. The wart-shaped perithecia, bearing a black-brown periostiolar dot that typically fades with age, likewise correspond to the published description and remain narrower than those of P. atriceps. Perithecia measure 0.4–0.55 mm (n = 28) in P. cf. karnatakensis 1 and 0.25–0.45 mm (n = 51) in P. cf. karnatakensis 2, consistent with the reported range of 0.3–0.5 mm. In the mtSSU phylogeny, sequences from both taxa do not cluster with the Neotropical P. karnatakensis subclade (Fig. 2). Nor do the two P. cf. karnatakensis taxa cluster together in either of the recovered ITS and mtSSU phylogenies (Figs 2, 3). Furthermore, in the absence of type-linked sequences, it remains uncertain if any of the recovered lineages might correspond to P. karnatakensis s. str. Several additional mtSSU sequences identified as P. karnatakensis from an unpublished Paleotropical study fall outside these lineages, clustering instead with P. aff. lucida 1 despite being inconsistent with the morphology currently attributed to P. karnatakensis. These identifications should therefore be interpreted cautiously. The mtSSU sequences of P. cf. karnatakensis 2 cluster with a specimen identified as P. cf. epiphylla by Ertz and Diederich (2022), which was likewise described as possessing a dark periostiolar region. The P. cf. karnatakensis 2 taxon additionally forms a supported group with P. cf. atriceps identified within this study, which is not surprising given their rough external similarities. Regarding their photobiont, P. cf. karnatakensis 1 is more selective and associates exclusively with algal haplotype 26: 11, whereas P. cf. karnatakensis 2 is more flexible and associates with three algal haplotypes (26: 1, 26: 2, and 26: 3) (Figs 4, 5). Overall, the uncertain application of the name P. karnatakensis, the absence of type-linked sequences, and the recovery of multiple distinct lineages prevent a confident assignment of the taxa to P. karnatakensis s. str. They are therefore retained as P. cf. karnatakensis 1 and P. cf. karnatakensis 2. Specimens examined. MADAGASCAR – Diego Suarez Prov. • Antsiranana, West of Sambava, Marojejy National Park, Camp Mantella area, trail to Cascade de Humbert, through rather dense humid evergreen lower montane forest, stream bank at waterfall of large exposed bedrock area, 14°25'58"S, 49°46'22"E, alt. ca. 480 m, 18 Oct. 2014; Ertz 20276 J (BR, TAN). – Toliara Prov. • ca. 25 km Northwest of Fort-Dauphin (Tolagnaro), National Park of Andohahela, South part of parcel 1, ca. 5 km West of the village of Malio, 24°56'07.0"S, 46°44'08.5"E, alt. 680 m, dense humid forest, 29 Nov. 2019, Ertz 25374 C (BR, TAN). • ibid., 24°55'43.4"S, 46°44'37.2"E, alt. 360 m, dense and humid forest at the bottom of a valley near a river bordered by large granite boulders, 27 Nov. 2019, Ertz 25303 G (BR, TAN). – MAYOTTE – Sohoa • Sohoa forest, 12°48'17.2"S, 45°06'47.6"E, alt. 150 m, mesophilic sloping forest, 05 Oct. 2017; Ertz 22135 B (BR), 22135 E (BR, MAO).