Hab.: In foliis Clusiae sp.
Holotypus: Guyana (Samuels 4854, N Y ).
Anamorph: None known
Perithecia solitary, superficial, non-stromatic,
anchored to substrate by hyphae, easily removed
from the substrate, globose to subglobose, 180-
260 Atm diam., nonpapillate, not collapsed when
dry, wall red when dry and in 3 % K O H , yellow
in 100% lactic acid, with a white furfuraceous
coating on the perithecial wall, ostiolar area glabrous;
the entire perithecium appearing white
with a red, areolate apex; furfuraceous coating
of amorphous material, dissolving in 3 % K O H.
Cells at the surface ofthe perithecial wall angular
in outUne, 10-20 µm, walls ca. 1 µm thick, not
perforated by pores. Perithecial wall ca. 25 µm
wide, exterior 1-2 layers of cells with angular to
circular lumina, 5-10 µm, walls to 2 µm thick;
cells of interior region ca. 10 µm wide, of 2-3
layers of cells with lumina elliptic to flattened,
10-15 µm long, walls ca. 2 µm thick but progressively
thinner toward the locule. Perithecial
apex of small, nearly circular cells with walls to
2 µm thick, ostiolar canal of narrow hyphal elements
arising from the inner perithecial wall
region and continuous with the periphyses. Paraphyses
not observed among mature asci. Asci
narrowly clavate, 50-70 x 7-10 µm, apex with
a minute refractive ring, 8-spored, sessile. Ascospores ellipsoidal, (8-)9-ll(-12.6) x (2.7-)3.2-
4(-4.5) µm, unicellular, colorless, smooth, partially
to completely biseriate in asci.
Habitat. Recently fallen leaves of Clusia spp.
Etymology of the Specific Epithet. Refers to
the host plant.
Known Distribution. Guyana.
TYPE. GUYANA. Cuyuni-Mazaruni Region, VH:
Mazaruni Subregion, VII-2, foothills immediately S of
Mt. Ayanganna, ca. 1 km W of Pong River, 05º28'N,
60º04'W, elev. 550-650 m, on decaying leaf of Clusia
sp., 26 Feb 1987, Samuels (4854), Pipoly, Gharbarran,
Chin & Edwards (holotype N Y , isotype BRG).
Additional Specimen Examined. GUYANA. Mt.
Wokomung, Wokomung Base Camp, ca. 8 hr walk NE
of Kopinang ViUage in tall, wet forest dominated by
Euphorbiaceae, 05°05'N, 59º50'W, elev. 1070 m, on
decaying leaves of Clusia sp., Jun-Jul 1989, Samuels
(6461), Boom & Bacchus (BRG, NY).
Notes. Pseudonectria clusiae is found only on
leaves of Clusia species that have recently fallen.
Because perithecia appear so quickly on these
leaves, and not on leaves of other trees, it is Ukely
that the species is an endophyte of Clusia.
The coating on the perithecial wall appears to
be hyphal when observed at low magnification.
In microscopic preparations in water no structure
was observed. In K O H the coating came
away from the perithecia in large sheets and then
Ascospores of neither of the specimens cited
above germinated on C M D at 20°C. Chaetopsina
cf. fulva RambeUi accompanied P. clusiae on both
of the collections (Fig. 41). The conidiophores
were more robust, and the conidia much larger
(17-18 X 2-3 Atm) than those described by Samuels
(198 5) for the Chaetopsina cf. fulva anamorph
of Nectria chaetopsinae Samuels.
Pseudonectria Seaver accommodates Nectria
Fr. species that have superficial, non-stromatic
perithecia and unicellular ascospores. It is a genus
of fewer than ten described species, of which
only a few have been critically examined. Pseudonectria
clusiae is anatomically similar to P.
rousseliana (Mont.) Seaver (Bezerra, 1963), the
type species of the genus. Perithecia of P. rousseliana
occur on living leaves of Buxus sempervirens
L.; they are described as light orange to
greenish and thick-walled setae arise from the
surface of the perithecial wall.