Leptogium hondae C.M. Bernardo, Kitaura & A.A. Spielmann, 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 : 135-136

Leptogium hondae C.M. Bernardo, Kitaura & A.A. Spielmann , sp. nov. ( Figures 2C–2E )

Diagnosis: Similar to Leptogium isidiosellum , but the isidia are restricted to the apothecia.

Holotype:— BRAZIL. Mato Grosso do Sul: Porto Murtinho, Fazenda Anahí , 21º40’30.54”S, 57º44’05.73”W, 88 m elev., corticolous, next to a road, 15 December 2015, J.M. Torres 509 ( CGMS).

MycoBank: 829954

Description: Thallus foliose, ca. 5 cm broad, dark brown to fluorescent light, opaque, matt, grayish to brownish under stereomicroscope. Lobes 0.5–1.0 mm wide, overlapping to agglomerated, attached in points, adpressed, upper surface ridged at naked eye, irregular ridged at 20× magnification; apices rounded, ascending, smooth; lateral margins ascending, smooth, irregular; lower side yellowish, ridged under 20× magnification. Isidia granular to cylindrical with age, simple, 0.05–0.25 × 0.05–0.1 mm, concolorous with the thallus, firm, erect, usually on the amphithecia, around the apothecia when present on the margin of thallus, ridged or withered. Lobules absent. Thallus attached by hapters, frequent, that does not originate cavities on the upper surface. Rhizines and hairs absent. Apothecia 1.0– 1.5 mm diam., marginal, adnate, disc brown, concave; margin beige to light brown, smooth and isidiate; amphithecia beige to light brown, isidiate; corona and pedicel absent. Anatomy: thallus 90–375 μ m thick, cortices with isodiametric cells 5.0 μ m diam. Medulla without columnar hyphae; cyanobacteria yellowish, 10–16 cells per filament, 2.5–5.0 × 2.5 μ m; gelatinous matrix abundant, yellowish. Apothecia with hymenium 150–175 μ m high; subhymenium 37.5–50.0 μ m, colorless; hypothecium 37.5–50.0 μ m thick, colorless, prosoplectenchymatous to subparaplectenchymatous at lower part; parahymenial tissue continuous with the hypothecium, elongated cells; proper exciple absent; thalline exciple cortex composed by paraplectenchymatous cells, 25.0–37.5 μ m (3–5 cells) thick at the apices, 62.5–75.0 μ m (5–7 cells) at the mid-height, 100–125 μ m (7–11 cells) at the base, with ducts filled by medullar components; basal paraplectenchymatous tissue absent. Ascospores fusiform, 25 − 27.5 × 12.5 − 15 μ m, apices acute to obtuse, muriform. Pycnidia not observed.

Notes. Leptogium hondae is characterized by ridged thallus and apothecia ornamented by isidia. The hypothecium is composed by two parts: upper part with prosoplectenchymatous tissue and lower part composed by colloplectenchymatous tissue. The thalline exciple cortex is constituted by thick paraplectenchymatous tissue.

Leptogium hondae was previously identified as L. isidiosellum , but all examined material has only isidia on the amphithecia and was considered a good species. Leptogium hondae differs from L. isidiosellum (Riddle) Sierk due to the type and distribution of the isidia. Leptogium hondae has isidia simple and usually on the amphithecia whereas L. isidiosellum has isidia simple to coralloid on the lamina and margin of the thallus and apothecia.

The epithet is a tribute to Dr. Neli Kika Honda, who produced meritorious lichenological contributions in Mato Grosso do Sul and has contributed to develop the Group of Lichenological Study in the state.

Distribution in Brazil: It is reported as new to science and was found in Aquidauana, Campo Grande, Jaraguari and Porto Murtinho, all in Mato Grosso do Sul state.

Examined material: BRAZIL. Mato Grosso do Sul: Aquidauana, Vila Palmeiras , on cortex, 17 November 1993, N.K. Honda, Devincenzi 049DH pr. p. (No. EQL 0638, CGMS) ; Campo Grande , UFMS campus, on cortex, 29 February 1989, I. Riquelme 060 (No. EQL 0060, CGMS) ; 0280 ( No. EQL 0451-A, CGMS) ; Jaraguari, Furnas do Dionísio , cerrado, near the top of a hill, on trunk, 20°08’50.30”S 54°34’08.10”W 498 m elev., 23 October 2010, L.S. Canêz, A.A. Spielmann 3461 ( CGMS 31784 ) ; 3464 ( CGMS 31787 ) ; 3470 ( CGMS 31793 ) ; 3446 ( CGMS); Porto Murtinho , next to the road BR 267 , 21º43’08.10”S, 57º37’12.10”W, 99 m elev., on a hill, corticolous, 12 June 2017, J.M. Torres et al. 599 ( CGMS) ; road next to morro Pão de Açúcar, 21º29’09.80”S, 57º55’46.10”W, 89 m elev., in a hill next to Paraguay river , corticolous, 13 June 2017, J.M. Torres et al. 632 ( CGMS) ; 637 ( CGMS).

Figures

FIGURE 2. A–F. Leptogium species. A. L. diaphanum (LC Canêz 3246). B. L. fusisporum (NK Honda 050). C–E. L. hondae (JM Torres 509, holotype). C. Detail of the thallus. D. Transversal section of the thallus. E. Transversal section of the apothecia, arrow = cortex of thalline exciple. F. L. isidiosellum (SS Moura 112). Bars: 2 mm (A–C, F); 50 μm (D–E).