Bactrospora medians Jagadeesh, 2014

Jagadeesh Ram, T. A. M., 2014, New species and new records in Roccellaceae (Arthoniales) from the Andaman Islands, India, Phytotaxa 177 (3), pp. 155-162 : 156-157

Bactrospora medians Jagadeesh , sp. nov. (Figs 1B, 2B & G–H) MycoBank no.: MB809894

Bactrospora with whitish grey to greenish grey, thin, endophloeodal thallus; I– and KI– excipulum; biclavate, (13–)15–24-septate, (54–)65– 90(–105) × 3.5–5(–5.5) μm, Homalotropa - type ascospores.

Type: — INDIA. Andaman Islands : North Andaman , Reef Island Wildlife Sanctuary, 13°30’16.0”N, 92°52’09.9”E, elev. 15 m, 18 Mar. 2012, T. A. M . Jagadeesh Ram 1236 (Holotype CAL) .

Thallus corticolous, mostly endophloeodal, whitish grey to greenish grey, up to 12 cm across, continuous, smooth, effuse, thin, ecorticate, 20–45 μm thick; prothallus dark brown to black, forming a border line. Photobiont Trentepohlia . Ascomata lecideine, moderate, black, scattered, erumpent, sometimes with thin uneven thalline margin, adnate to sessile, constricted at base, ± rounded, 0.5–0.8(–0.9) mm diam.; margin usually excluded; disc plane to convex, epruinose. Excipulum dark brown laterally and carbonized and indistinct from hypothecium at base, 30–60 μm thick laterally, K + greenish brown, I –, KI–. Epihymenium brown to dark brown, K + greenish brown. Hymenium hyaline, not inspersed, 140–160 μm high, I – or I + orange, KI+ pale blue. Subhymenium pale brown to dark brown, gradually becoming carbonized, 30–70 μm thick, I – or I + orange, KI– or KI+ pale blue. Hypothecium dark brown, carbonized, up to 250 μm thick, extending to the substrate, K + greenish brown, I –, KI– or KI+ pale blue. Paraphysoids dichotomously branched, sometimes weakly anastomosing, 1–1.5 μm wide; tips not thickened, branched and anastomosing. Asci clavate, 8-spored, Bactrospora - type, 105–140 × 14–18 μm. Ascospores hyaline, Patellarioides - type when young and Homalotropa - type at maturity, biclavate and tapering at one end, (13–)15–21(–24)-septate, (54–)65–90(–105) × 3.5– 5(–5.5) μm. Chemistry: Thallus K –, C –, KC–, P –, UV –; I + red, KI+ blue (in section); no lichen substances detected.

Notes: — Bactrospora medians is closely related to Bactrospora intermedia Egea & Torrente which is known only from Chile has similar I –, KI– excipulum and Homalotropa - type ascospores. However, Bactrospora intermedia has a thin excipulum at base, KI+ pale blue turning reddish hymenium and KI+ pale blue subhymenium and 19–30–septate ascospores. It is also very close to B. micareoides Kantvilas , an Australian species having similar ascospores, but that has much small ascomata (0.15–0.3 mm diam.), KI+ deep blue excipulum and 22–30-septate ascospores ( Egea & Torrente 1993, Kantvilas 2004).

Distribution and habitat: — Bactrospora medians is known from the seashore forests in Reef Island of the North Andaman and Henry Lawrence Island of the South Andaman.

Etymology: —The specific epithet refers to the intermediate size of ascospores.

Additional specimen examined: — INDIA. Andaman Islands : South Andaman, Henry Lawrence Island, elev. 10 m, 11 May 2012, T. A. M . Jagadeesh Ram 1939 ( PBL) .