Monographs Details: Fomitiporella johnsoniana Murrill
Authority: Fidalgo, Oswaldo & Fidalgo, Maria E. 1968. Polyporaceae from Venezuela. I. Mem. New York Bot. Gard. 17 (2): 1--34.
Description:Species Description - MACROSCOPIC CHARACTERS. sporophore: effused-reflexed, imbricate, often entirely resupinate, firm, compact, heavy and woody, pileus: reflexed when formed, up to 2.5 cm long, up to 4.5 cm wide and 3 cm thick, abhymenial surface: very hard, encrusted, velutinate to glabrous, concentrically zonate, narrowly sulcate, brownish-black, MP-8J11 (Montella). margin: entire, obtuse, velvety, paler than the abhymenial surface, bright yellow-brown, MP-13E6 (Arizona). context: ligneous, very hard, dense, up to 2 mm thick, reddish-brown, MP-8L9 (Maracaibo), without black lines but limited at the surface by a black crust, 0.2-0.3 mm thick; with KOH the trama darkens but does not react intensively, tubes: in several indistinct layers, up to 5 mm long in each layer, ferruginous, MP-7A12 (Argus Brown), not pruinate. poroid surface: yellowish- to reddish-brown, usually MP-15E8 (Mustang +), with a sort of shine; pores minute, regular, circular or somewhat elliptic, (8-)9-11(-12) per mm, (46-)64-82.5(-92) µ diam; dissepiments entire, acute, 30-40 (-60) µ, thick. MICROSCOPIC CHARACTERS, surface: complex; represented by a crustiform cortex up to 600 p. thick without clear predominant orientation of the hyphae, covered by a crustiform palisadoderm up to 20 µ thick, formed by anticlinal hyphae, both portions built predominantly by generative hyphae 1-2 µ diam, yellow, thin-walled to somewhat thickened, with simple crosswalls and compactly agglutinated, context: dimitic hyphal system; generative hyphae hyaline to yellowish, thin-walled, 1-2.5 µ diam, branched, with simple crosswalls and no clamp-connections; some generative hyphae yellowish, binding-like, very tortuous and much branched, with abundant crosswalls; skeletal hyphae yellow to ferruginous, thick-walled to solid, with scattered spiny projections at the surface, 2-3.5 µ diam, lumen darker than the wall, no true crosswalls but with pseudo-crosswalls present. dissepiment: dimitic; generative hyphae hyaline to yellowish, thin-walled, 1-2 µ diam, with simple crosswalls; skeletal hyphae, yellow to pale ferruginous, thick-walled to nearly solid, 1.5-2.5 µ diam, with no crosswalls. hymenium: hyphal pegs and cystidia not present; hymenial setae very variable in color, shape, thickness, size and frequency, pale yellow to ferruginous, thin- to thick-walled, conical to subulate, (10-) 20-30 (-40) X (4.5-) 6-8 (-11) µ, sharp-pointed, tips straight and projecting beyond the hymenium 9-15 µ and according to the place examined they may be common or very scarce; basidia small, clavate, hyaline, 4-sterigmate, 5-7.5 X 3-5.5 µ basidiospores smooth, thin-walled, hyaline to yellow or light yellowish-brown with age, ellipsoid, broadly ovoid to nearly globose, non-amyloid, 2.5-4.5 X 2-4 µ.

Distribution and Ecology - Distribution. It has been previously recorded from the U. S. A. and Canada. The type collection of Pyropolyporus underwoodii is from Puerto Rico, near Coamo Springs, Underwood dc Griggs 239, Jun 14-Jul 22, 1901; the specimen of Fomitiporella johnsoniana which came mixed with the type collection of P underwoodii is the first record of the presence of F johnsoniana in Puerto Rico and in the tropics. It had never been reported from South America. This is the first report from Venezuela. VENEZUELA. Amazonas: Orinoco River, Caño Tama - Tama, a black water cano just above Tama-Tama, on right bank of Orinoco River, 150 m alt, Wurdack d Adderley 43162, Jun 23, 1959 (NY). Habitat, Host and Economic Importance. Reported to occur only on wood of angiosperms; no host is known from Venezuela. It produces a decay which starts as a white mottled rot and in advanced stages it transforms into a white soft laminated type as described from heart rot of Fra.rinus sp. from Louisiana, Ohio and Virginia in the U. S. A. (Davidson, Lombard & Campbell, 1959: 1148-1149).


Fig. 1.

Poria johnsoniana (Murr.) Sacc. & Trott. in Sacc, Syll. Fung. 21: 329-330. 1912.

Fames johnsonianus (Murr.) Lowe, Polyp. N. Amer., The genus Fomes. 36-37. 1957.

Erroneous Interpretations

Fomes densus auct. non Lloyd: Overh., Mycologia 23(2): 127. 1931; Campbell, Bull. Torrey Club 65(1): 41. 1938; Overh., Bull. Torrey Club 65(3): 174. 1938; Polyp. U.S. Alaska Can. 80-81. 1953.

Poria pereffusa auct. non (Murr.) Sacc. & Trott.: Weir (see Lowe, 1957: 37).

Type. Holotype, coll. Johnson 1764 at NY; isotypes at BPI, F H.

Type Locality. Ann Arbor, Alichigan, U. S. A.

Basionym. Fomitiporella johnsoniana Alurr., 1907.

Discussion. Murrill (1907b: 13) described Fomitiporella johnsoniana as having 5-6 pores per mm and no cystidia; in the type the pores are 9-11 per mm and the setae, although almost absent in some areas, are always present, measuring (13-)20-30(-40 )x (5-)6-8(-11) µ. Overholts (1953) mistook it for Fomes densus Lloyd, and Lowe (1952b: 231) considered it as a synonym of Phellinus dependens (Murr.) Imaz. Later, Lowe (1957: 36-37) recognized F. johnsoniana and P dependens as distinct, calling attention to the difference in shape and size of the setae of both species, which according to the drawings are quite different. We would also maintain these species as distinct, although in structure they are very similar and therefore closely related; however, we do not consider the differences in shape and size of the setae as the basic differences between them. In the tropics species of Phellinus and allied genera with thickened ventricose or subulate setae often have setae which are less thickened, somewhat longer and elongated than when they occur in temperate zones. This is exactly what happens with F. johnsoniana. Its type came from near the extreme north of the geographical distribution of the species. In the type we found setae 20-40 X 7-11 µ of the shape indicated by Lowe (1957), as well as a few ventricose, very thickened setae up to 17.5 X 7.5 µ as described for the setae of P dependens. In F. johnsoniana the ventricose and small thickened setae become more and more frequent in the collections from near the tropics. Specimens of F. johnsoniana are extensively attached to the substrate, mostly resupinate, more rarely effuse-reflexed to somewhat imbricate, but the forward projected portion of the pileus does not reach more than 2.5 cm from the base; pores are minute, 9-12 per mm; the abhymenial surface is rarely rimose mostly not showing the deep radial furrows. Phellinus dependens has its point of attachment to the substrate restricted to a small area; the fruitbody projects downward, and becomes entirely ungulate and pendent; the pores are a little larger, 7-9 (-10) per mm and the abhymenial surface is rimose with deep radial furrows. At NY two specimens supposed to belong to the type collection of Pyropolyporus underwoodii Murr. were found. One, kept in a box, is ungulate, has 3 pores per mm and agrees with the original description (Murrill, 1903: 116). The other one maintained on a sheet has a handwritten note: "part of the type." It is effused-reflexed, has pores 65-85 µ diam and dissepiments 25-60 µ thick, which means 9 or more pores per mm; the basidiospores are not more than 4.5 µ long and setae, although extremely scarce, are present, measuring 10-23 X 5-6 µ. The latter specimen is F. johnsoniana.