History of name
Laccaria fraterna
(Cooke & Massee: Saccardo) Pegler
Agaricus fraternus Cooke & Massee in Cooke, Grevillea 16: 31. 1887,
non Agaricus fraternus Lasch, Linnaea 3: 402. 1828 (= Cortinarius sp.).
Naucoria fraterna (Cooke & Massee) Saccardo, Syll. Fung. 9: 110. 1891.
Laccaria fraterna (Cooke & Massee: Saccardo) Pegler, Austral. J. Bot.
13: 332. 1956.
Naucoria goosensiae Beeli, Bull. Soc. Roy. Bot. Belgique 61: 88. 1928.
Laccaria laccata f. bispora Heinemann, Bull. Jard. Bot. État 34:
310. 1964. (change of name).
Laccaria lateritia Malençon, Bull. Soc. Mycol. France 82: 189. 1966.
Type: Australia: vic. Port Phillip, French no. 1 (K!, holotype).
Species Synopsis:
Pileus mostly 10-35 mm broad, not striate to slightly translucent when fresh, rusty
red-brown. Lamellae pinkish rose. Stipe 25-65 mm long, striate, concolorous with
pileus; basal mycelium white. Basidia 2-sterigmate. Cheilocystidia lacking. Basidiospores
mostly 8.5-11 X 8-10.5 µm (excluding ornamentation), globose to subglobose,
echinulate; spines mostly 1-1.8 µm long, * 1 µm wide at base. Introduced
to North America, associated only with Eucalyptus.
Habitat and Distribution:
Under Eucalyptus and other introduced trees. Laccaria fraterna was
probably introduced along with Eucalyptus throughout the world. Commonly collected
under Eucalyptus throughout the world, including North America. See Specimens Examined for the list of specimens studied.
Observations:
Laccaria fraterna can be distinguished from other small Laccaria
taxa by its rusty red-brown basidiomata and 2-sterigmate basidia which bear globose
to broadly ellipsoid basidiospores that are < 11 µm long.
There has been considerable confusion in the literature concerning the correct name
for this taxon. Some workers have used the name L. ohiensis for this
taxon (e.g., Singer, 1942, 1946, 1949, 1967, 1975, 1977; McNabb, 1972), but an examination
of the holotype revealed that L. ohiensis has 4-sterigmate basidia. While
the most commonly used name for the taxon has been L. lateritia, the correct
name for this taxon is L. fraterna (Mueller and Vellinga, 1986; Vellinga and
Mueller, 1987).
Tom W. May (University of Melbourne, personal communication) reports the finding
of a potentially paratypic collection at MEL that better fits the protologue but
that is not contaxic with the type specimen housed at Kew. It has been assumed that
the report of ellipsoid basidiospores in the original diagnosis of A. fraternus
probably referred to another collection on the type sheet at KEW which was collected
in New Zealand (Pegler, 1965; Mueller and Vellinga, 1986). If the collection housed
at MEL is lectotypified, A. fraternus would not fit into the generic circumscription
of Laccaria and the correct basionym for the taxon treated here would be N.
goosensiae.
Ballero and Contu (1989) described L. singeri Ballero & Contu. This name,
however, is a later homonym of L. singeri Locquin & Sarwal (Sarwal and
Locquin, 1983) and Mueller and Vellinga (1990) renamed it L. impolita Vellinga
& G. M. Mueller. Laccaria impolita is similar in micromorphology to L.
fraterna but differs from it in basidioma color, lack of pileus striations, and
ectomycorrhizal hosts (north temperate trees).
Macromorphology:
Pileus 9-35(-55) mm broad, strongly convex to convex, becoming plane to uplifted,
often slightly depressed, not striate to slightly translucent-striate, finely fibrillose
to fibrillose, rusty red-brown (8D7 to 9E7), eventually becoming buff; margin decurved
to plane, entire to slightly undulate; context thin, concolorous with pileus. Lamellae
adnate, moderately distant to distant, thick, pinkish rose (near 8A3). Stipe
(17-)25-65 x 3-5 mm, equal or slightly clavate, at times caespitose, dry, fibrillose,
moderately longitudinally striate, concolorous or slightly darker than pileus (9C5-9D6).
Basal mycelium white, often copius. Basidiospores white in mass.
Micromorphology:
:Pileipellis of interwoven hyphae with scattered fascicles of ± perpendicular
hyphae; fascicles composed of 10-20 hyphae; terminal cells of fascicular hyphae 26-69
x 6.5-15 µm, filamentous to clavate; walls up to 0.5 µm thick, light yellowish
brown. Pileus trama tightly interwoven, morphologically undifferentiated,
hyaline, light yellowish brown toward pileipellis. Lamellar trama parallel;
hyphae mostly 3-10(-15.5) µm diam, thin-walled, hyaline to light yellowish brown;
cells barrel-shaped. Subhymenium morphologically undifferentiated. Basidia
29-46 x 8-12 µm, clavate, hyaline; sterigmata 2(-3), up to 11 µm long.
Cheilocystidia not observed. Basidiospores (excluding ornamentation)
[100/4] (7.8-)8.5-11(-13.5) x (7.4-)8-10.5(-13.5) µm [ = 9.7-10.5 x 8.9-9.9
µm], Q = 1-1.18(-1.22) ( = 1.01-1.11], globose to subglobose, hyaline, strongly
echinulate; echinulae 1-1.8 µm long, * 1 µm wide at base, crowded; hilar
appendix 1.3-2.8 µm long, prominent, truncate; plage present; contents occasionally
uniguttulate.