Leptogium moluccanum var. denticulatum C.M. Bernardo, A.A. Spielmann & Kitaura, 2019

Kitaura, Marcos J., Bernardo, Caique M., Koch, Natália M., Rodrigues, Andressa S., Torres, Jean-Marc, Barbosa, Thiago D., Canêz, Luciana Da S., Spielmann, Adriano A., Honda, Neli K., Fleig, Mariana & Lorenz, Aline P., 2019, Leptogium (Collemataceae, Peltigerales) from Mato Grosso do Sul state, Brazil: nine new records, three new taxa and a key for the species, Phytotaxa 399 (2), pp. 127-146 : 139-140

Leptogium moluccanum var. denticulatum C.M. Bernardo, A.A. Spielmann & Kitaura , var. nov. ( Figures 3D–3F )

Diagnosis: Similar to Leptogium denticulatum Nyl. (1867: 302) , but differs in having ornaments on the apothecia and columnar hyphae.

Holotype:— BRAZIL. Mato Grosso do Sul: Jaraguari, Furnas do Dionísio , 20°09’00.5”S 54°34’28.2”W, 440 m elev., corticolous, 01 March 2015, C.M. Bernardo, T. D. Barbosa 465 ( CGMS).

MycoBank: 829956

Description: Thallus foliose, 2.0–7.0 cm broad, gray to fluorescent light, opaque, bright to matt, bluish gray to yellowish gray under stereomicroscope. Lobes 2.0–5.0 mm wide, slightly agglomerated, attached in points, adpressed, upper surface smooth to naked eye, smooth or rugulose to slightly bullate under 20× magnification; apices rounded, plane to ascending, smooth; lateral margins ascending, smooth, sinuous and undulated; lower side yellowish, smooth under 20× magnification. Isidia and lobules absent. Thallus attached by hapters, frequent, originating cavities on the upper cortex. Rhizines and hairs absent. Apothecia 0.4–1.0(–1.5) mm diam., laminal, subpedicellate, very short, disc reddish, plane; margin concolorous with the thallus, smooth or with circular wrinkles, originating verrucules with rounded apices; amphithecia beige, smooth; corona that originates with age, intermittent, unusual; pedicel very short. Anatomy: Thallus ca. 75 μ m thick, cortices with isodiametric cells, 5.0 μ m diam., medulla with columnar hyphae usually straight, 4–5 cells high, abundant to frequent; cyanobacteria green, 10–20 cells per filaments, 2.5–5.0 × 2.5 μ m; gelatinous matrix frequent, colorless. Apothecia with hymenium ca. 125 μ m high, subhymenium 37.5–50.0 μ m thick, colorless, hypothecium up to 50 μ m thick, colorless, prosoplectenchymatous of irregular cells; parahymenial tissue continuous with the hypothecium, subparaplectenchymatous; proper exciple absent; thalline exciple cortex composed by paraplectenchymatous cells, 5.0 μ m (one cells) thick at the apices and mid-height, 35–50 μ m (6–10 cells) thick at the base; basal paraplectenchymatous tissue absent. Ascospores fusiform, 17.5–22.5 × 7.5×10.0 μ m, apices acute to obtuse, muriform. Pycnidia not observed.

Notes: Leptogium moluccanum var. denticulatum is characterized by subpedicellate apothecia, with corona when young and bluish circular wrinkles with age; columnar hyphae are straight, 4–5 cells high.

The pedicel of Leptogium moluccanum var. denticulatum is short like in L. moluccanum var. moluccanum (Pers.) Vain. and pedicellate apothecia were not found in the analyzed specimens. The apices of the apothecia of L. moluccanum var. denticulatum have corona and circular wrinkles and are similar to L. denticulatum Nyl. , but not originating denticules with acute apices.

Furthermore, the columnar hyphae of L. denticulatum is constituted by 2 cells whereas L. moluccanum var. denticulatum has columnar hyphae with 4–5 cells.

Leptogium tuckermanii C.W. Dodge has apothecia with 0.5–0.9 mm diam., with smooth and pale margin, and ascospores 18–22 × 10–12 μ m ( Dodge 1933) and differs from L. moluccanum var. denticulatum which has apothecia 0.4–1.0(–1.5) mm diam., with margin concolorous with the thallus, smooth or with circular wrinkles, originating verrucules with rounded apices, and ascospores 17.5–22.5 × 7.5×10.0 μ m.

The etymology of the epithet refers to the Maluku Islands, where the species was originally described; and the etymology of the variety “ denticulatum ” refers to Leptogium denticulatum Nyl. , once the apothecia of L. moluccanum var. denticulatum resemble the apothecia of this species.

Distribution in Brazil: It is here described as new, found in the municipality of Jaraguari.

Examined material: BRAZIL. Mato Grosso do Sul: Jaraguari, Furnas do Dionísio , corticolous, 20°09’00.5”S 54°34’28.2”W, 440 m elev., 14 November 2015, C.M. Bernardo, T. D. Barbosa 880 ( CGMS) ; 882 (CGMS); 915 (CGMS).

Figures

FIGURE 3. A–B. Leptogium species. A. L. marginellum (AA Spielmann 8367). B. L. microcarpum (AL Simal 188). C. L. milligranum (SR Ramalho 44). D–F. Leptogium moluccanum var. denticulatum (CM Bernardo 465). D. Detail of the thallus. E. Transversal section of the thallus, arrows = columnar hyphae. F. Transversal section of the apothecia, arrow = subparaplectenchymatous parahymenium tissue. Bars: 2 mm (A–D); 50 μm (E); 100 μm (F).