Obba
Obba Miettinen & Rajchenb. 2012, in Miettinen& Rajchenberg, Mycological Progress, 11, 131-147 (2012).
Etymology: Obba (Lat.), a type of household container for liquids used in Rome; refers to the broad bottle-shaped cystidioles characteristic of the genus.
Description: Basidiocarp resupinate, annual to biennial, white when fresh, cream to ochraceous when dry, a few millimetres up to 13 cm long, up to 3 mm thick. Consistency soft when fresh, drying hard to brittle. Subiculum thin, cartilaginous line when dry. Hyphal system monomitic, clamps present, CB–, IKI–, CRB+. Hyphae mostly thin-walled to slightly thick-walled, mostly 2–3 μm in diameter. Coarse crystal rosettes in trama and tube mouths, (2)4–7(9) μm in diameter, also rhomboidal plates. Subicular hyphae often agglutinated. Tramal hyphae interwoven to subparallel, tissue rather dense, upper trama may be agglutinated. In KOH part of hyphal walls swell inwards and gelatinise, resulting in a capillary, distinct lumen. Free oil droplets present in microscopic slides. Cystidia none. Hymenium. Cells large (about 15–20×6–9 μm), with oily contents. Basidia mostly clavate, with 4 sterigmata. Cystidioles subulate to mammiform, common. Basidiospores subglobose to globose, CB(+), plasma stained in CB, with a large hyaline oil droplet, thin- to slightly thick-walled, smooth.
Index Fungorum Number: IF519509
Type species: Obba valdiviana (Rajchenb.) Miettinen & Rajchenb. 2012, in Miettinen& Rajchenberg, Mycological Progress, 11, 131-147 (2012).
Species:
Obba rivulosa (Berk. & M.A. Curtis) Miettinen & Rajchenb. 2012
Obba thailandica G.J. Ren & F. Wu 2017
Obba valdiviana (Rajchenb.) Miettinen & Rajchenb. 2012
Reference:
Miettinen, O., & Rajchenberg, M. (2012). Obba and Sebipora, new polypore genera related to Cinereomyces and Gelatoporia (Polyporales, Basidiomycota). Mycological Progress, 11, 131-147.
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