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Page number:317 
Description type:Non-original description 
Description:Fomitopsis rubidus (Berk.) Roy & De, comb. nov.
Basionym : Polyporus rubidus Berk.,.Lond. J. Bot. 6 : 500, 1847. Basidiocarp annual, rarely biennial to perennial, sessile or effused-reflexed, corky, becoming woody on age, dimidiate to semicircular, applanate, conchate or some ungulate, imbricate, 2.0-6.0 x 1.0-3.5 x 0.2-0.5 cm; upper surface cinnamon buff to µmkish brown, at first minutely tomentose, soon glabrous, zonate; margin thin, slightly incurved; context light µmkish brown, fibrous, 1.0-2.5 mm thick; hymenial surface light µmkish brown to pale cinnamon, pores small, circular to subangular, 6-8 per mm, pore tubes up to 3 mm long.
Hyphal system trimitic. Generative hyphae hyaline, thin-walled, clamped, 1.5-2.5 µm wide (Fig.1). Skeletal hyphae (Fig.2) hyaline or nearly so, thick-walled to subsolid, straight or flexuous, 2.5-4.5 pum wide. Binding hyphae (Fig.3) moderately branched, hyaline, thick-walled to solid, 2.5-4.5 pum wide. Basidia (Fig.4) clavate, 4-sterigmate, 10-15 x 3-5 µm. Basidiospores hyaline, thin-walled , smooth, cylindric-ellipsoid, apiculate, 5.0-7.5 x 3.5-4.0 µm (Fig.5), amyloid, cyanophilous.
SPECIMENS EXAMINED : VBMH 80701 on dead wood of Bambusa arundinacea Willd.; VBMH 80702 on dead wood of Tectona grandis L.f., VBMH80 ˱ log of Shorea robusta Gaertn. f.; VBMH 84704 on dead wood of Polyporus VBMH 84705 on dead wood of Castanea sativa MI R- 85705 on dead wood of Dipterocarpus indicus Bedd.; VBMH 86706 on dead wood of Eucalyptus citriodora Hook.; VBMH 87707 on dead branch of Michelia sp.; VBMH 89708- on dead wood of Terminalia tomentosa Wright et Arn.
DISTRIBUTION IN INDIA : Dehra Dun (U.P.), Calcutta (W.B.), North and South India.
From the foregoing description it is evident that this species possesses trimitic hyphal system. The hyphal system. i.e. monomitic, dimitic, or trimitic of a species has been considered to be taxonomically important in circumscribing genera (Bondartzeva 1961, Teixeira 1962, Donk 1964, Fidalgo and Fidalgo 1967). These authors would not include two species with different hyphal systems in the same genus. Thus Polyporus rubidus Berk. possessing a trimitic hyphal system, can not be placed under the dimitic genus Polyporus Mich. ex. Fr.
Ryvarden (197 studied the type specimen of Polyporus rubidus Berk. and concluded that it was "Trametes feei (Fr.) Pat." Later Ryvarden and Johansen (1980) listed P. rubidus as a synonym of T. feei. Ryvarden (1977) and Ryvarden and Johansen l980) regarded P. rubidus (=T. feei) as a member of the genus Trametes Fr. because P. rubidus resembles Trametes suaveolens (L.:Fr.) Fr., the type species of the genus Trametes Fr., by the following features : (i)pileus surface tomentose when young but becomes glabrous when old; (ii)pores circular to angular; (iii)hyphal system trimitic with clamped generative hyphae; and (iv)hyaline, thin-walled, smooth basidiospores. But our study reveals that P. rubidus causes brown rot, gives negative result in oxidase test and possesses bipolar type of sexuality whereas T. suaveolens causes white rot, gives positive result in oxidase test and possesses tetrapolar type of sexuality (Nobles 1965). These differences rule out the possibility of considering P. rubidus and T. suaveolens as congeneric.
Critical observations on the morphological, cultural and certain biological characters of Polyporus rubidus Berk. reveal its close relationship with Fomitopsis pinicola (Swartz: Fr.) Karst., the type species of the genus Fomitopsis Karst. Both produce effused-reflexed to sessile, woody, applanate to ungulate basidiocarps with circular pores. Both have a trimitic hyphal system with hyaline, clamped generative hyphae; ellipsoid-cylindric, hyaline, smooth, delicate-walled basidiospores; and cause brown rot of wood. The cultural characters of the two are similar as evident by comparing the species code of F. pinicola which is with that of P. rubidus given above. Moreover, both the species give negative result in oxidase test and show bipolar sexuality. The great number of similarities between the two species indicate a phylogenetic relationship. Therefore, it is concluded that Polyporus rubidus and Fomitopsis pinicola are congeneric and the transfer to Fomitopsis is proposed.
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