Monographs Details: Hexagona Fr.
Authority: Fidalgo, Oswaldo & Fidalgo, Maria E. 1968. Polyporaceae from Venezuela. I. Mem. New York Bot. Gard. 17 (2): 1--34.
Family:Polyporaceae
Scientific Name:Hexagona Fr.
Description:Species Description - Fruiting body lignicolous, annual, very rarely biennial, sessile, usually attached to the substrate by an attenuated base or small portion of the pileus, solitary to imbricate, dimidiate, flabelliform, applanate to conchate, very rarely effusedreflexed; coriaceous, corky-coriaceous to corky, rarely sublignose; pilear surface always with a shade of brown to blackish, strigose to velutinate; context brown, permanently darkening in KOH solution, subhomogeneous, fibrose; hymenial surface always poroid, usually with angular, hexagonal pores, very rarely with subcircular or subdaedaloid pores, never lamellate; tubes usually nonstratose but in two species occasionally indistinctly stratified. Pilear surface originally a trichoderm, fasciculate or loose, falling off or not; with age the outer layer of the pileus usually a cutis but in two species an atypical hymeniderm and a paraderm present. Context and dissepiments a trimitic hyphal system. Context, when seen in sections, of two more or less distinct layers: a compact lower layer of densely interwoven hyphae showing no definite orientation and a somewhat loose and fibrose upper layer, formed of hyphae mostly with periclinal orientation. Dissepiments formed by densely interwoven hyphae without a definite orientation. Subhymenium inconspicuous. Generative hyphae hyaline, septate, with clamps, branched, thin-walled, usually collapsed in the mature fruiting body. Skeletal hyphae yellowish-brown to brown, rarely with yellow walls, unbranched, thick-walled but mostly with a distinct lumen, rarely subsolid or solid, nonseptate, but many times with delicate, thin, simple septa near the apical region of the hypha. Binding hyphae hyaline to yellowish-brown, much branched to coralloid, with short branches, nonseptate, thick-walled to solid. Hymenium: lined by basidia and basidioles, frequently interrupted by the projection of hyphal pegs; true cystidia and setae not found; hyphal pegs always present, yellow, yellowish-brown to dark brown, built by skeletal hyphae closely attached to generative hyphae projecting beyond the hymenium, usually conic, in one species truncate and sometimes forked; cystidioid hyphae observed in two species represented by the projected endings of skeletal hyphae; pseudo-setae, dark brown and thick-walled, observed in one species; basidia clavate, tetrasterigmate, in most species apparently collapsing very early and forming a honeycombed structure; basidiospores hyaline, cylindrical, smooth, not amyloid, very seldom found in herbarium specimens. Species of tropical distribution.

Discussion:

Hexagona Fr., Fl. Scan. 339. 1835; Gen. Hymen. 11. 1836; Epicr. Syst. Mycol. 496. 1838, pro parte; Nova Acta Soc. Sci. Upsal. III. 1: 100, 1851, pro parte, non Hexagonia [Pollini, Pl. Nov. Horti ct Prov. Veron. 36. 1816].

Favolus [P. Beauv., Fl. Oware 1: 1.1805].

Polyporus subg Favolus (P. Beauv.) ex Fr.. Syst. Mycol. 1: 342. 1821, pro parte.

Favolus (P. Beauv. ex Fr., Syst. Orb. Veg. 76. 1825, pro parte, non Favolus Fr., Elench. Fung. 1: 44. 1828.

Polyporus trib Scenidium Kl., Linnaea 7: 200. 1832.

Scenidium (Kl.) Kuntze, Rev. Gen. Pl. 3(2): 515. 1898, pro parte.

Trametes sect Fibrosae Pat., Essai taxon. 92. 1900.

Pogonomyces Murr., Bull. Torrey Club 31: 609. 1904.

Type. Holotype not indicated; lectotype is Hexagona crinigera Fr., selected by Clements and Shear (1931: 347).