Pararhexoacrodictys minima Cantillo & Gusmão, 2019

Cantillo, Taimy, Almeida, Davi Augusto Carneiro De, Monteiro, Josiane Santana & Gusmão, Luís F. P., 2019, Pararhexoacrodictys (Incertae sedis, Ascomycetes) gen. nov., new combinations and new records of hyphomycetes from Brazil, Phytotaxa 397 (2), pp. 199-209 : 203

Pararhexoacrodictys minima Cantillo & Gusmão sp. nov. Fig. 2

MycoBank MB 824304

Etymology: —referring to the smaller size of conidiophores and the conidia when comparing with Pa. balansae .

Colonies effuse, brown to dark brown on natural substrate. Conidiophores macronematous, mononematous, erect, straight, arising singly or in small groups, cylindrical, smooth, light brown, darker at base, 30–55.5 × 4.5–7.5 μm. Conidiogenous cells monoblastic, integrated, terminal, cylindrical, with 1 (rarely 2) percurrent extension, pale brown, smooth. Secession rhexolytic. Conidia solitary, dry, acrogenous, holoblastic, variable in shape and cupulate, subglobose, globose or closely palmate, light brown, smooth, 30–37.5 × 21–46.5 μm. Basal cell distinctly protuberant, cuneate, truncate, 6.5–8 × 4–6.5 μm. Appendages 4–12 or more, aseptate, undulate, pale brown to subhyaline at apex, smooth, 6.5–9 × 1.5–3 μm, clustered at the apex or dispersed all over conidial body.

Material examined: — BRAZIL. Bahia: Serra da Jibóia, Santa Terezinha, from decaying bark tree, 12°46’S 39°31’W, 28 February 2006, L.F.P. Gusmão s.n (HUEFS 225278).

Notes:— When comparing this species with Pa. balansae (Y.R.Ma & X.G.Zhang) Cantillo & Gusmão comb. nov. (this article), they both have cylindrical conidiogenous cell, similar conidial shape and swollen undulate appendages. Differences are that conidiophores and conidia are larger in Pa. balansae (50–160 × 4.5–12 μm for conidiophores and 42–68 × 28–62 μm for conidia); also, appendages are frequently clustered at conidial apex and conidial shape is more variable than the described by Ma et al. (2016), having some cupulate (= turbinate) conidia with an almost palmate appearance ( Fig. 3E ). This last feature is similar to the observed in some conidia of Pa. magnicornuata (Fiuza, Gusmão & R.F. Castañeda) Cantillo & Gusmão comb. nov. (this article) but differentiated from the latter by the smaller conidia with shorter and not circinate appendages.

Geographical distribution:— BRAZIL. Bahia: Serra da Jibóia (this paper).

Figures

FIGURE 2. Pararhexoacrodictys minima (HUEFS 225278, holotype). A: conidia; B- E conidiophores and conidia; G. Bar =20 μm.

FIGURE 3. New records for Brazil: A Pseudoacrodictys aquatica HUEFS 203037. B, Pseudoacrodictys limoniaceae HUEFS 203038. C- E Shrungabeeja varijadencens HUEFS 216690: C, conidial bottom with striations from side and bottom view; hyaline septate hyphae observed in conidia initials (D) and in a fully development conidia (E). Scale bars: A–C, E, F= 20 μm; D= 30 μm.