Chloridium aquaticum M.J. Wei & H. Zhang, 2018

Wei, Ming-Jie, Zhang, Huang, Dong, Wei, Boonmee, Saranyaphat & Zhang, Di, 2018, Introducing Dictyochaeta aquatica sp. nov. and two new species of Chloridium (Chaetosphaeriaceae, Sordariomycetes) from aquatic habitats, Phytotaxa 362 (2), pp. 187-199 : 192-193

Chloridium aquaticum M.J. Wei & H. Zhang , sp. nov. ( Fig. 3 )

Type: — THAILAND. Chiang Rai: Khun Korn, on submerged wood, 26 February 2011, H. Zhang, e3 (holotype: MFLU 11-1133), ex-type culture MFLUCC 11-0212.

Index Fungorum number: — IF 554804; Facesoffungi number: —FoF 04771;

Etymology: — In reference to the aquatic habitat, where the holotype was collected.

Colonies on natural substrate, effuse, thinly hairy, greenish-grey or brown. Mycelium partly superficial, partly immersed, consisting of branched, septate, smooth, thin--walled, subhyaline hyphae. Stroma none. Setae and hyphopodia absent. Conidiophores 316–415 × 2.8–10.6 μm (= 379.17 × 6.06 μm, n = 10), macronematous, mononematous, scattered, solitary, cylindrical, wider at the base, slightly flexuous, erect, 1 or 2 whorls per conidiophore, whorl Penicillium -like, mid to dark brown, paler towards the apex, septate, smooth. Conidiogenous cells terminal, determinate, borne on top of the whorl, cylindrical, subhyaline to pale brown. Conidia 3.4–5.5 × 1.1–2.7 μm (= 4.38 × 2.06 μm, n = 10), acrogenous, solitary or formed in slimy masses, ellipsoidal to cylindrical, straight, hyaline, unicellular, smooth, thin-walled, with two guttula. Sexual morph: Undetermined.

Known distribution: — Thailand.

Culture characteristics: — On PDA, colony circular, reaching 23 mm in 13 days at 25°C, white at first, becoming yellowish when old, ring striate, olivaceous at the third ring, surface velvety with raised elevation in the center, dry, edge entire.

Notes: — Phylogenetic analysis shows that it clusters with C. aseptatum and C. gonytrichii in Chloridium . The obvious morphological difference between them is the number of whorls: C. aquaticum has 1–2 whorls in the each conidiophore, while C. aseptatum has no whorl and C. gonytrichii has 5–8 whorls in the each conidiophore. C. aquaticum is most similar to C. terricola in having Penicillium -like conidiophores, but C. aquaticum has 1–2 whorls and slimmer conidia (length/width = 2.13 vs. 0.95) (Wang et al. 2017).

Figures

FIGURE 3. Chloridium aquaticum (holotype, MFLU 11-1133). a–b. Colonies on substrate. c. Conidiophore. Note the percurrent proliferation. d–f. Conidiogenous cells. g. Colonies on PDA. h–i. Conidia. Bars: a–b = 150 μm, c = 50 μm, d–f = 30 μm, h–i = 5 μm.