Griggsia F.L. Stevens & N. Dalbey

Thambugala, Kasun M., Singtripop, Chonticha, Chunfang, Yu, Mckenzie, Eric H. C., Liu, Zuo-Yi, Chukeatirote, Ekachai & Hyde, Kevin D., 2014, Towards a natural classification of Dothideomycetes 7: The genera Allosoma, Austropleospora, Dangeardiella, Griggsia and Karschia (Dothideomycetes incertae sedis), Phytotaxa 181 (1), pp. 34-46 : 43-45

Griggsia F.L. Stevens & N. Dalbey , Bot. Gag. 68(3): 222–224 (1919)

MycoBank: MB 2137

Type species:— Griggsia cyathea F.L. Stevens & N. Dalbey , Bot. Gaz. 68(3): 222–224 (1919) MycoBank: MB 228343. FIG. 6 a–u .

Epiphytic on leaves of Cyathea arborea ( Cyatheaceae ). Sexual state: Ascomata 132–198 µm high × 204–261 µm diam. (x = 132 × 243 µm, n=5), superficial, stromatic on epidermis, gregarious, thick-walled, dimidiate, dark brown to black, without ostiole, opening by irregular cleavage of internal vegetative mycelium at the apex. Peridium 34–62 µm diam, thick-walled, comprising cells forming a textura angularis, brown to dark brown at the outer layer, hyaline at inner layer. Hamathecium comprising of thick-walled, cylindrical, hyaline, long, filamentous, septate, branched, apically free paraphyses. Asci 59–81 long × 17–35 µm wide (x = 76 × 24 µm, n=10), 8-spored, unitunicate, broadly obovoid, short-pedicellate, apically rounded. Ascospores 26–36 × 10–13 µm (x = 36 × 12 µm, n=15), overlapping, broadly to elongate-oval, with rounded ends, hyaline, 1-celled and rough. Asexual state: Conidiomata 90–119 µm high × 193–236 µm diam. (x = 104 × 213 µm, n=5), pycnidium, superficial, epidermal, dimidiate, circular, black, closely reticulate and numerous, opening by a rugged cleft. Conidiomata wall 21–32 µm wide, comprising thick-walled cells forming a textura angularis, brown to dark brown outside, with hyaline inner layer of cells. Conidiogenous cells 11–15 × 6–8 µm (x =12 × 7 µm, n=5 µm, n=10), phialidic, short, cylindrical, integrated, hyaline, with a short collarette at the tip. Conidia 26–34 µm high × 8–15 µm diam. (x = 28 × 13 µm, n=20), broadly obovoid to pyriform, truncate at the base, rounded at the tip.

Material examined:— PUERTO RICO. Maricao: Alto de Bandera, on Cyathea arborea ( Cyatheaceae ). 14 & 19 July 1915. F. L . Stevens. No. 8276 and 8794. ( NY 01102841 !, holotype) .

Notes:— Griggsia was introduced by Stevens & Dalbey (1919) as a monotypic genus and is typified by Griggsia cyathea . It is characterized by superficial ascomata, filamentous, unbranched, septate, pseudoparaphyses, unitunicate, broadly obovoid asci and broadly oval, hyaline, 1-celled ascospores. Lumbsch & Huhndorf (2010) included this genus under Dothideomycetes, genera incertae sedis. Griggsia should be excluded from Dothideomycetes because asci are unitunicate ( Schoch et al. 2006, Hyde et al. 2013). Therefore we place Griggsia in Sordariomycetes incertae sedis pending molecular investigation. The species needs recollecting, sequencing and epitypifying in order to clarify the familial status.

Figures

FIGURE 6. Griggsia cyathea (NY 01102841, holotype). a. Material label. b. Appearance of sexual state on host. c. Section through ascoma. d. Peridium. e. Paraphyses. f–i. Mature asci. j Ascospore. k.Appearance of asexual state on host. l. Section through fruiting body m, n. Close up of conidiogenous cell with conidia. o. Peridium. p–u. Conidia. Scale bars: b, k = 200 µm, c = 100 µm, d, l = 50 µm. f–h = 30 µm, e, i, m–n = 20 µm, j, o–u = 10 µm.**i–j. Redrawn from Stevens and Dalbey (1919).