Cladonia termitarum Ahti, 2013

Ahti, Teuvo & Sipman, Harrie J. M., 2013, Ten new species of Cladonia (Cladoniaceae, Lichenized Fungi) from the Guianas and Venezuela, South America, Phytotaxa 93 (1), pp. 25-39 : 37-38

Cladonia termitarum Ahti , sp. nov. ( Fig. 10)

Mycobank # MB 803527

Thallus squamulosus, aggregatus, squamulae minutae (0.3–1 mm longae), crustaceae, crassae, subteretia, marginibus crenulatis, interdum parce sorediosis. Podetia brevissima (0.5–2 mm), laevia, granulosa vel squamosissima, semper fertilia. Conidiomata subsphaerica, demum ostiolum hians , gelatinam coccineam continentia. Disci hymeniales applanati, coccinei. Acidum fumarprotocetraricum et acidum rhodocladonicum continens.

Type:— GUYANA. Potaro-Siparuni Region: Kaieteur Falls National Park , S side of airstrip, 0.5º10’N, 59º29’W, 400 m elev., on termite structure on premontane sclerophyll forest floor, 1996, T. Ahti et al. 53023 (holotype BRG!, isotypes B!, H!, US!).

Primary thallus persistent, appearing crustose but consisting of 0.3–1 mm long, 0.1–0.5 mm wide, pale greenish to brownish grey squamules, usually very short and irregular, convex, thick, often warty or almost cylindrical, often densely aggregated, crenulate at ends and margins, with eroded, granulose patches extending on the underside of the squamules; necrotic basal parts becoming orange. Podetia often numerous, very short (0.5–2 mm), of determinate growth, greenish grey; stalk smooth (little corticate), granulose or densely squamulose. Podetial surface areolate-verruculose. Podetial wall not measured. Conidiomata scattered, subspherical, black, 0.2 mm tall, after ejaculation of conidia ostiolum gaping open with black, toothed margins and red slime visible inside. Hymenial discs sparsely produced, on very short (0.5–2 mm), smooth, granulose or squamulose podetia, flat, purple. Chemistry: PD + fast brick red, containing the fumarprotocetraric acid complex; the purple pigment rhodocladonic acid in hymenial discs and conidiomata.

Distribution and ecology:— A Guianas endemic, known so far only from three collections made near the Kaieteur Falls, Guyana. It was exclusively observed on old forest floor termite structures, at ca. 400 m elev. These structures are very common in the Amazonian and associated lowland rainforests, therefore the species is expected to be more widespread.

Additional specimens examined (paratypes):— GUYANA. Potaro-Siparuni Region, type locality, termite mound, Ahti 53020 ( BRG!, H!, US!) ; Kaieteur Falls National Park, N side of airstrip, termite mound, Ahti 53035 (B!, BRG!, H!) .

Remarks:— The short-stalked, bright red ascomata in combination with the presence of fumarprotocetraric acid set this species well apart from all Guianas lichens. The only similar species is Cladonia ahtii Stenroos , known from SE Brazil, which belongs to the group of C. miniata , and differs by the shape of the squamules, thick and rounded, with a flat to concave upper surface.