R E I N W A R D T I A

Published by Herbarium Bogoriense — LBN, Bogor
Vol. 9, Part 2, pp. 221 — 223 (1975)

A NOTE ON PODOCONIS MEGASPERMA BOEDIJN

MIEN A. RIFAI
Herbarium Bogorienses, Bogor, Indonesia

ABSTRACT

The lectotype specimen of Podoeonis megasperma is selected and this
species is reclassified as Exosporium megaspermum (Boedijn) Rifai, a
newly proposed combination. An illustrated redescription is presented.

ABSTRAK

Spesimen lektotipe untuk Podoeonis megasperma ditentukan dan jenis
ini diklasifikasikan sebagai Exosporium megapermum (Boedjjn) Rifai,
yang merupakan suatu kombinasi baru. Suatu pertelaan bergambar di-
sajikan.

Examination of the original specimens of Podoeonis megasperma
Boedijn (1933) revealed that this species cannot be considered to be conge-
neric with Podoeonis theae (Rant) Boedijn sensu Boedijn (1933) — the
lectotype and only other original species of the genus Podoeonis Boedijn
(Hughes 1953), which in turn was treated as a synonym of Sporidesmium
Link ex Fr. by Ellis (1958, 1971) — because its conidiogenous cells are
tretic and not monoblastic. The majority of these cells appear monotretic
so that at a glance Podoeonis megasperma resembles a species of Coryne-
spora Giissow. A diligent search for more mature conidiophores indicates,
however, that their proliferation is not percurrent through the previous
pore because in renewing their apices these conidiophores grow sympo-
dially. Consequently when proliferation took place the conidial scar was
pushed aside and the apical portion of the old conidiophore became irre-
gularly frayed, as has been illustrated by Boedijn (1933: 126, fig. 4/5).
Therefore Podoeonis megasperma should be classified as a species of
Exosporium Link ex Fr. as this genus is understood by Ellis (1961,
]971), inspite of the fact that its stroma is rather poorly developed and
its conidia are euseptate; in this respect this species resembles Exosporium
ampullaceum (Fetch) M.B. Ellis.

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222 R E I N W A R D T I A [VOL. 9 1975] RIFAI: On Podoconis megasperma
223

As Boedijn (1933) did not indicate which of the seven specimens he
cited should serve as the holotype specimen, the collection Boedijn 366 is
here formally indicated as the lectotype of Podoconis megasperma.

Exosporium megaspermum (Boedijn) Rifai, comb. nov. — Fig. 1

Podoconis -megasperma Boedijn in Bull. Jard. bot. Buitenz. I l l , 13: 133, fig. 3/15,
4/5, 7. 1933 (basionym).

Colonies widely effused, brownish black to black, finely hairy. Myce-
lium mostly immersed in the substrate, consisted of much branched,
septate, pale brown to brown, smooth walled, 1.8 — 4,5µm diam. hyphae.
Stromata poorly developed, immersed, composed a very few layers of
polygonal cells. Conidiophores arise singly or at the most in a group of
two's or three's, terete, unbranched, straight or flexuous, dark brown to
reddish brown and paler towards the slightly swollen apex, up to 480 µm
long by 8 —11.5 µm diam., often enlarged to about 18.5 µm diam. at the
base, septate, smooth walled. The outer wall of the conidiophore is
slightly thickened and dark at the apex and after the first conidium
which develops through a pore in the centre of this thickened apex has
fallen, the conidiophore grows out laterally below the scar splitting the
side wall and pushing the scar to one side, then growing for some distance
before forming the second conidium at the newly constituted apex. Conidia
maturing acrosporously, broadly obclavate to subfusoidal, often rostrate,
with truncated dark scars at the base, smooth walled, dark reddish brown
but paler towards the apex, 4 — 7 septate with the second cell from
below largest, 60 — 90 µm long by 20 — 28.5 µm wide at the widest part,
tapering to 3 •—- 4.5µm near the apex.

WEST JAVA. On decayed stems, Cibodas Nature Reserve, April 1930, Boedijn
SS2 (BO 11529), Boedijn 333 (BO 11458), Boedijn 366 (BO 11373, lectotype), Boedijn
515 (BO 11281); ibid., December 1930, Boedijn 945 (BO 12002); ibid., August 1931,
Boedijn 1597 (BO 12753), Boedijn 1599 (BO 12754).

REFERENCES
In Bull. Jard.BOEDIJN, K.B. (1933). Ueber eininge phragmosporen Dematiazeen.

'bot. Buitenz. I l l , 13: 120—134.
ELLIS, M.B. (1958). Clasterosporium and some allied Dematiaceae - Phragmospora

I. In C.M.I. Mycol. Pap. 70: 1—89.
ELLIS, M.B. (1961). Dematiaceous Hyphomycetes III.In C.M.I. Mycol. Pap-
ELLIS, M.B. (1971). Dematiaceous Hyphomycetes. Comm. Mycol. Inst.,
HUGHES, S.J. (1953). Podoconis in Britain. In Naturalist, Lond. 864:

Fig. 1. Exosporium megaspermum (from Boedijn 366)


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