Phaeogyroporus portentosusSynonymsGyroporus portentosus Phlebopus marginatus Phlebopus portentosus Boletus marginatus Boletus portentosus
BiostatusPresent in region - Origin uncertain
Images (click to enlarge) Caption: FIG. 1 e, Phaeogyroporus portentosus: e, spores. | Caption: Fig. 6 - a, Phaegyropus portentosus (x 1/3) |
Article: McNabb, R.F.R. (1968). The Boletaceae of New Zealand. New Zealand Journal of Botany 6(2): 137-176 (http://www.rsnz.org/publish/abstracts.php). Description: PILEUS: convex,
plano-convex, applanate or centrally depressed with reflexed margins, 14-23-(29)
cm diam., dry, tomentose to velutinate, often creviced with age, olive brown
to dark olive brown, occasionally dull brownish black in places, sometimes tinted
reddish brown, crevices khaki; cuticle a trichodermium, composed of erect, branched
hyphae 4-7 µm. diam., with clamp connections and rounded or acuminate apices,
terminal cells with brown contents; margin entire, often extending beyond pores,
sterile. HYMENOPHORE: tubes to 15mm long, slightly excavated around apex of
stipe, sordid yellow to yellowish brown when young, olive brown at maturity;
pores at first concolorous with tubes, darker at maturity, small, regular, 0.5-0.75
mm diam. STIPE: 4-8 cm long, stout, ventricose-bulbous, 3-5 cm diam. apically,
to 7 cm diam. basally, solid, dry, coarsely sulcate basally, finely tomentose
to velutinate, concolorous with pileus, deep mustard brown or dull brownish
black, usually darker basally; flesh sordid white to pallid fawn, at length
becoming pinkish on exposure to air, annulus absent.
SPORES: spore print
olive brown (Buffy Citrine); spores deep melleous, short-elliptical, obovate
or occasionally broadly obpyriform, 7.5-10-(13.5) X 5-7.2-(9.9) µm smooth. HYMENIUM:
basidia hyaline, clavate, 18-25 X 4-6 µm., 4-spored; cystidia absent. HYMENOPHORAL
TRAMA: bilateral, of the Boletus subtype, containing conspicuous oleiferous
hyphae to 11 µm. diam.; clamp connections present. CONTEXT OF PILEUS: white
to sordid white when young, becoming pallid fawn to pallid creamy yellow at
maturity, flushed with pink on exposure to air with greenish blue areas at apex
of stipe and immediately above tubes. TASTE: slightly acrid with oily texture.
SMELL: not distinctive. CHEMICAL REACTIONS: KOH on pileus—dark reddish brown;
on context of pileus—no definite reaction; NH4OH on pileus—dark reddish brown;
on context—faint pink flush. Habitat: HABITAT: Gregarious or occasionally solitary under native
broad-leaved trees and shrubs. Notes: It seems likely that Phaeogyroporus portentosus
is an indigenous species, for an immature specimen, indistinguishable from similarly
aged specimens of P. portentosus, has been collected in dense native
forest near Rotorua by Mr. G. B. Rawlings. When the natural geographical distribution
of the species is considered (Australia, Ceylon, Indonesia), its presence in
the warmer parts of New Zealand is not unexpected.
The mycorrhizal
status of P. portentosus is uncertain. Earlier descriptions contain little
information about its habitat, but, on the basis of field observations, Fisch
(1945) suggested that in Australia it formed mycorrhizal associations with Eucalyptus.
The fungus has appeared in the Auckland Domain for a number of years and is
restricted to a small area in a planted border of native trees and shrubs. The
only plant with which it could form an association in this area is a single
tree of Nothofagus truncata. The collection from Meadowbank was not associated
with any known mycorrhizal plant.
New Zealand specimens
agree closely with earlier descriptions of the species and with Australian specimens
identified by Cleland (ADW), except that both Fetch (1907) and Boedijn (1951)
described the pileus as smooth. P. portentosus readily fits within Singer's
(1962) circumscription of Phaeogyroporus. although cystidia are absent.
It seems likely that Phaeogyroporus is a later synonym of Phlebopus
(Heim) Singer 1936. Singer (1962) regarded Phlebopus as a nomen dubium
on the doubtful grounds that the type specimen of Boletus colossus Heim,
the only species originally described in the genus, was no longer in existence.
Heim (1965) recently pointed out that specimens of B. colossus are preserved
in Paris (PC). The two genera appear to be closely related and, if on re-examination
of B. colossus the presence of clamp connections is demonstrated, it
will be difficult to maintain them as separate genera.
The genus Phaeogyroporus
contains some of the largest Agaricales known: Cleland (1935) reported that
specimens of P. portentosus reached 60 cm in diameter and weighed up
to 7 lb 2 oz. P. portentosus is regarded as an edible species in Australia.
The species may be distinguished by the large, olive brown
fruitbodies, short-elliptical spores, and the presence of clamp connections.
It has not previously been recorded from New Zealand.
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