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Lasionectriella, a new genus in the Bionectriaceae, with two
new species from France and Spain, L. herbicola and L. rubioi
Christian LECHAT
Jacques FOURNIER
Ascomycete.org, 8 (2) : 59-65.
Mars 2016
Mise en ligne le 15/03/2016
Abstract: Lasionectriella rubioi gen. and sp. nov. and L. herbicola sp. nov. are described and illustrated based
on collections from France and Spain. The asexual morph of L. rubioi was obtained in culture and cultures of
both species were sequenced. The genus is placed in the Bionectriaceae based on ascomata not changing
colour in 3% KOH or lactic acid, acremonium-like asexual morph and phylogenetic comparison of LSU se-
quences with species in 13 genera of the Bionectriaceae. Lasionectriella is primarily characterized by subglo-
bose, pale yellow, pale orange to dark brownish orange, non-stromatic ascomata with a conical apex and
ascomatal surface covered by thick-walled hyphae proliferating from base and agglutinating to form a fringe
around the upper margin of ascomata. It is morphologically and phylogenetically compared with the most
similar genera Ijuhya, Lasionectria and Ochronectria.
Keywords: acremonium-like, Ascomycota, Hypocreales, Ijuhya, Lasionectria, ribosomal DNA, taxonomy.
Résumé : Lasionectriella rubioi gen. et sp. nov. et L. herbicola sp. nov. sont décrits et illustrés d’après des ré-
coltes eectuées en France et en Espagne. La forme asexuée de L. rubioi a été obtenue en culture et les cul-
tures des deux espèces ont été séquencées. Le genre est placé dans les Bionectriaceae d’après les ascomes
ne changeant pas de couleur dans KOH à 3% ou dans l’acide lactique, la forme asexuée acremonium-morphe
et la comparaison des séquences LSU avec des espèces représentant 13 genres de Bionectriaceae. Lasionec-
triella caractérisé par des ascomes subglobuleux, jaune pâle, orange pâle à orange-brunâtre foncé, non stro-
matiques, à sommet conique et la surface couverte d’hyphes à paroi épaisse se développant depuis la base
et s’agglutinant pour former une frange autour de la marge de l’ascome. Lasionectriella est morphologique-
ment et phylogénétiquement comparé avec les genre Ijuhya, Lasionectria et Ochronectria.
Mots-clés : acremonium-morphe, Ascomycota, Hypocreales, Ijuhya, Lasionectria, ADN ribosomal, taxinomie.
Introduction
In the course of a survey of hypocrealean fungi in Europe, three
collections on Ruscus aculeatus L. (Liliaceae) and one on unidentied
herbaceous stem were intriguing because of their unusual type of
vestiture. They were assigned to the Bionectriaceae based on their
pale yellow, pale orange or brownish-orange ascomata not chan-
ging colour in 3% KOH or lactic acid, which was conrmed by phy-
logenetic comparison of their LSU sequences with those of 13 other
bionectriaceous genera (Fig. 3). As they feature an ascomatal wall
less than 25 µm thick, composed of thick-walled cells, covered by
thick-walled hairs aggregated into a fringe around the upper margin
of perithecia, they appeared to closely resemble Lasionectria (Sacc.)
Cooke (COOKE, 1884) and Ijuhya Starbäck (STARBÄCK, 1899). However,
a thorough morphological comparison of our collections with these
genera showed a dierence in type of vestiture and in our phyloge-
netic dendrogram they appeared distant from the Lasionectria clade
and the Ijuhya clade and instead clustered with Ochronectria Ross-
man & Samuels on a separate branch. As our collections are mor-
phologically clearly dierent from the monotypic tropical genus
Ochronectria characterized by smooth thick-walled ascomata, the
wall of which comprises a middle layer rich in orange oily droplets,
we feel justied to introduce the new genus Lasionectriella to ac-
commodate our collections. As the three collections on Ruscus de-
viate from that on herbaceous stem by larger and spinulose
ascospores, they are accommodated in two dierent species, viz. L.
rubioi and L. herbicola respectively.
Both species were successfully cultured but only L. rubioi yielded
an acremonium-like asexual morph, while the culture of L. herbicola
remained sterile. The dierences of Lasionectriella with Lasionectria
and Ijuhya are discussed and an illustrated morphological compari-
son of Lasionectriella with Ochronectria is provided.
Materials and methods
The specimens were examined, cultured, sequenced and phylo-
genetically analysed using the methods described in LECHAT & FOUR-
NIER (2015).
Taxonomy
Lasionectriella Lechat & J. Fourn., gen. nov.
MycoBank 815673.
Diagnosis: Diers from Lasionectria and Ijuhya by a conical apex
and thick-walled hairs covering the ascomatal wall, proliferating
from base and agglutinating to form a fringe around the upper mar-
gin of perithecia.
Type species: Lasionectriella rubioi Lechat & J. Fourn.
Etymology: Lasionectriella refers to the resemblance of its hairy
ascomata with Lasionectria.
Lasionectriella rubioi Lechat & J. Fourn., sp. nov. – Fig. 1
MycoBank 815674.
Diagnosis: Ascomata supercial, non-stromatic, subglobose, cu-
pulate upon drying, pale yellow, pale brownish orange to reddish
brown, not changing colour in 3% KOH or lactic acid, covered by
thick-walled hairs arising from base, agglutinated and proliferating
to form a fringe around upper margin of perithecia; ascomatal wall
18–25 m thick composed of thick-walled, globose or ellipsoidal to
attened cells; asci 8-spored, fusoid-clavate without apical appara-
tus; ascospores 10–12 × 2–2.5 m, equally two-celled, spinulose.
Holotype: FRANCE, Deux-Sèvres: Villiers-en-Bois, Forêt de Chizé,
1 Mar. 2015, on dead stem of Ruscus aculeatus, leg. C. Lechat,
CLL15078 (LIP). Ex-type culture CBS 140157, GenBank KU593581.
Additional specimens examined (paratypes): FRANCE, Deux-Sè-
vres: Villiers-en-Bois, Forêt de Chizé, 30 Mar. 2012, on dead stem of
Ruscus aculeatus, leg. C. Lechat, CLL12011 (LIP); Culture: CBS 132543.
SPAIN, Asturias: Soto de los Infantes, 27 Jan. 2008, on dead stem of
Ruscus aculeatus, leg. E. Rubio, CLL7155 (LIP).
60 Ascomycete.org
Fig. 1 – a-h: Lasionectriella rubioi (holotype CLL15078). a-b: Ascomata on host substratum, c: Ascomatal wall in vertical section, d: Tip of
hairs covering ascomatal surface: Ascus and ascospores, f: Culture after two weeks, g: Conidia, h: Conidiophore and conidia.
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Fig. 2 – a-h: Lasionectriella herbicola (holotype CLL15077). a-b: Ascomata on host substratum, c: Vertical section through ascoma, d:
Vertical section through ascomatal wall, e: Culture after two weeks, f–g: Asci and ascospores.
Etymology: The epithet rubioi refers to the distinguished Spanish
mycologist Enrique Rubio Dominguez who collected the rst spe-
cimen of Lasionectriella.
Ascomata gregarious, solitary or crowded in groups of 3–8, su-
percial, subglobose, apex conical, 140–170 µm high × 140–180 µm
diam (X = 165 ×175 µm, n = 10), white when immature, later dark
orange to brownish-orange, collapsing cupulate when dry, not
changing colour in 3% KOH or lactic acid. Hyphae covering ascoma-
tal surface 2–3 µm diam, developing from ascomatal base, prolife-
rating and agglutinating to form a fringe around upper margin of
perithecia, hyaline to pale yellowish when dry, thick-walled, wall 1–
1.5 µm thick, swollen and rounded at tip, septate, intertwined and
dicult to separate. Perithecial wall 15–25 µm thick, composed of
two regions: outer region 10–15 µm wide, of globose to ellipsoid
cells 2–5 × 2.5–4.4 µm with hyaline to pale yellow wall; inner region
5–10 µm wide, of elongate, attened, hyaline cells 5–8 × 1.5–2.5 µm.
Asci 55–65 × 6–8 µm (X = 60 ×7.5 µm, n = 30), clavate to fusoid,
apex attened, without ring, with 8 irregularly biseriate ascospores.
Paraphyses moniliform, 8–12 µm wide at base, inserted between
asci. Ascospores (8.5–) 9–12 (–14) × 2.2–2.5 (–2.8) µm (X = 10.4
×2.4 µm, n = 30), hyaline, fusoid, rounded at ends, straight to lightly
curved, equally 2-celled, constricted at septum, spinulose, with two
yellow drops in each cell.
Asexual morph: acremonium-like.
Cultural characteristics: Colony after two weeks at 25°C on PDA
25–30 mm diam., greyish green in centre, white at margin, reverse
greenish yellow; after three weeks colony reaching 40–45 µm diam.,
greyish green in centre, white in median area and green at margin,
producing no coloration in medium. Mycelium with hyphae bran-
ching, septate, hyaline to pale brown, smooth, 3–5 µm diam. Coni-
diophores borne on aerial hyphae, macronematous,
mononematous, unbranched, exuous, hyaline, faintly roughened,
2.5–3.5 µm diam. Conidiogenous cells monophialidic, 23–45 µm
long, 1.5–1.8 µm wide at apex with a ared collarette, 2–2.2 µm wide
at base. Conidia grouped at tip of phialide to form a mucous head,
aseptate, narrowly ellipsoidal to subcylindrical with rounded apex,
attenuated at base with an apiculate hilum, walls smooth, at rst
hyaline, becoming dark green, appearing nearly black in mass, 3.5–
5.5 × 1.8–2.2 µm (X = 4.5 × 2 µm, n = 30).
Lasionectriella herbicola Lechat & J. Fourn., sp. nov. – Fig. 2
MycoBank 815675.
Diagnosis: Diers from L. rubioi by smooth smaller ascospores 8–
10 × 2–2.5 m.
Holotype: FRANCE, Deux-Sèvres: Villemanan, Chanc, 23 Apr. 2015,
on dead herbaceous stems, leg. Suzanne Buissonnet, CLL15077 (LIP).
Ex-type culture CBS 140156. GenBank: KU593582.
Etymology: The epithet herbicola refers to the substrate on which
this species was collected.
Ascomata gregarious, solitary or crowded in groups of 2–9, su-
percial, subglobose, apex conical, 120–150 µm high × 130–160 µm
diam (X = 145 ×150 µm, n = 10), dark brownish-orange, collapsing
cupulate when dry. Hyphae covering ascomatal surface 2–3 µm
diam, developing from ascomatal base, proliferating and agglutina-
ting to form a fringe around upper margin of perithecia, hyaline to
pale yellowish brown, thick-walled, wall 1–1,5 µm thick, cylindrical
and rounded at tip, septate, tightly intertwined and impossible to
separate. Perithecial wall 20–25 µm thick, composed of two re-
gions: outer region 15–20 µm wide, of subglobose to ellipsoidal,
thick-walled cells 4–10 × 2.5–3.5 µm with hyaline to pale yellow wall
1–1.5 µm thick; inner region 5–7 µm wide, of elongate, attened,
hyaline cells 5–8 × 1–1.5 µm, with sparse orange, oily droplets bet-
ween the cells and hymenium. Asci 45–55 × 5–7 µm (X = 50 ×6 µm,
n = 30), clavate to fusoid, apex attened, without ring, with 8 irre-
gularly biseriate ascospores. Paraphyses narrow, moniliform, 4–
6 µm wide at base, inserted between asci. Ascospores (7.5–) 8–10
(–11) × 2.2–2.5 (–2.8) µm (X = 9 ×2.3 µm, n = 30), hyaline, fusoid,
rounded at ends, straight to lightly curved, equally 2-celled, smooth,
with two yellow drops in each cell.
Asexual morph: unknown.
Cultural characteristics: Colony after two weeks at 25°C on PDA
25–30 mm diam., white in centre, greyish white to greyish yellow in
median area and white at margin, radially furrowed, reverse pale
yellow to pale yellowish brown; occose aerial mycelium white to
pale yellow in median area, white at margin, without coloration of
the medium. No conidia produced in culture after four weeks.
Discussion
Lasionectriella is characterised by the combination of pale brow-
nish orange to pale reddish brown ascomata with wall composed
of thick-walled cells not changing colour in 3% KOH or lactic acid,
collapsing cupulate upon drying, a conical apex surrounded by a
crown of hyaline to pale yellow, thick-walled entangled hairs and
an acremonium-like asexual morph. This set of characters strongly
suggests anities with the Bionectriaceae as dened by ROSSMAN et
al. (1999), especially with the genera Ijuhya and Lasionectria.
Ijuhya primarily diers from Lasionectriella and Lasionectria in ha-
ving ascomata usually with a at, discoidal apex and fasciculate hairs
agglutinated to form triangular teeth arranged in a stellate fringe
around the upper margin of the perithecia.
Lasionectria is morphologically the genus most closely related to
Lasionectriella in having hairs scattered over the ascomatal surface.
However, ascomatal hairs in Lasionectria are solitary or bound in
triangular fascicles while in Lasionectriella they cover the whole as-
comatal surface, developing from ascomatal base, proliferating and
agglutinating to form a fringe around the upper margin of perithe-
cia. The value of these morphological dierences of ascomatal ves-
titure is supported by our phylogenetic analysis showing
Lasionectriella is fairly distant from both Ijuhya and Lasionectria
(Fig. 3). We also considered comparing Lasionectriella to the mono-
typic genus Stephanonectria Schroers & Samuels which likewise be-
longs to the Bionectriaceae and features a crown-like structure
around the ostiolar area (SCHROERS et al., 1999). However, in S. keithii
(Berk. & Broome) Schroers & Samuels perithecia are stromatic, apical
crown is cellular, not hyphal as in Lasionectriella, ascospores are or-
namented with short striae and asexual morph, referred to myro-
thecium-like, diers from the known asexual morph of
Lasionectriella in being penicillate and in yielding hyaline conidia.
This set of morphological characters deviating from Lasionectriella
is supported by the position of S. keithii in our phylogram which
clusters with Bionectria ochroleuca (Schw.) Schroers & Samuels on a
distant branch. Moreover, Myrotecium appears very distant from Ste-
phanonectria, which suggests that the asexual morph of Stephano-
nectria is closer to Clonostachys (= Bionectria) than to Myrothecium
(Fig. 3).
This molecular analysis, comparing 13 genera in the Bionectria-
ceae, shows that the closest genus to Lasionectriella is Ochronectria.
Ochronectria, a monotypic genus known only from the tropics, has
an acremonium-like asexual morph (ROSSMAN et al., 1999), like Lasio-
nectriella, but is distinguished by glabrous ascomata seated on a
thin basal subiculum, ascomatal wall 45–60 µm thick, three-layered,
comprised of thin-walled cells, containing abundant orange oily
droplets in the median region, and multiseptate and striate
ascospores (Fig. 4). Despite apparent phylogenetic anities, Ochro-
nectria cannot be equated with Lasionectriella because of these
strong morphological dierences. However, the presence of sparse
orange oily droplets in hymenium and ascomatal wall observed in
62 Ascomycete.org
L. herbicola is reminiscent of Ochronectria, which also has orange
droplets but considerably more abundant than in L. herbicola. It is
unknown whether this character explains the apparent phylogene-
tic relationship between both genera. Thus, based on morphologi-
cal, cultural and molecular data, the new bionectriaceous genus
Lasionectriella is introduced to accommodate the new species L. her-
bicola and L. rubioi.
We do not regard the occurrence of moniliform basal paraphyses
reported here from both species of Lasionectriella as a dierential
character for the genus. While the absence of true basal paraphyses
is regarded as typical of Hypocreales (ROSSMAN et al., 1999), we repea-
tedly observed such moniliform paraphyses in either bionectria-
ceous or nectriaceous collections, provided that the material is fresh
and barely mature. These sparse, fragile, thin-walled paraphyses li-
kely deliquesce rapidly upon maturation of the centrum and cannot
be detected in dry herbarium material.
Lasionectriella herbicola is primarily distinguished from L. rubioi
by smaller and smooth ascospores and possibly by a dierent host
aliation. Further dierential characters which should be conrmed
by examination of more specimens are the overall darker ascomatal
colour of L. herbicola and the presence of sparse orange droplets in
hymenium and ascomatal wall. Finally, the fact that, under the same
conditions of culture, L. rubioi yields an asexual morph while L. her-
bicola does not is likely a further dierential character between the
two species.
The repeated occurrence of L. rubioi on Ruscus aculeatus suggests
a strong host-preference for this plant, if not host-specicity. It is no-
teworthy that several Hypocreales seem to be specic for this host,
including Coccinonectria rusci (Lechat, Gardiennet & J. Fourn.)
L. Lombard & Crous (LOMBARD et al., 2015) and others still under in-
vestigation.
Fig. 3 – Maximum likelihood phylogeny of Lasionectriella spp. inferred from comparison with LSU sequences of 13 genera in the Bionec-
triaceae, rooted with Geejayessia desmazieresii (Nectriaceae).
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64 Ascomycete.org
Fig 4 – a-i: Comparison of Lasionectriella spp. with Ochronectria. a-c: Ascomata in natural environment; a: Lasionectriella rubioi (holotype),
b: Lasionectriella herbicola (holotype), c: Ochronectria calami*; d–f: vertical section through ascomatal wall, g-i: Asci and ascospores in
lactic blue. *FWI, Martinique, Sainte-Marie, Forêt départementalo-domaniale, La Philippe; 22 Aug. 2012, on spathe of Cocos nucifera L.
CLLM12059 (LIP).
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Acknowledgments
The authors gratefully acknowledge Dr Amy Rossman (Oregon
State University, U.S.A.) for her advices and scientic help and for
her presubmission review. Suzanne Buissonnet and Enrique Rubio
Dominguez are warmly thanked for the material they collected, on
which this work is based.
References
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LOMBARD L., MERWE N.A. (VAN DER), GROENEWALD J.Z. & CROUS P.W. 2015. —
Generic concepts in Nectriaceae. Studies in Mycology, 80: 189-245.
ROSSMAN A.Y., SAMUELS G.J., ROGERSON C.T. & LOWEN R. 1999. — Genera
of Bionectriaceae, Hypocreaceae and Nectriaceae (Hypocreales, As-
comycetes). Studies in Mycology, 42: 1-248.
SCHROERS H.-J., SAMUELS G.J. & GAMS W. 1999. — Stephanonectria, a new
genus of the Hypocreales (Bionectriaceae), and its sporodochial
anamorph. Sydowia, 51 (1): 114-126.
STARBÄCK K. 1899. — Ascomyceten der ersten Regnellschen Expedi-
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ef
Jacques Fournier
Las Muros
09420 Rimont
France
jacques.fournier@club-internet.fr
Christian Lechat
64 route de Chizé
79360 Villiers-en-Bois
France
lechat@ascofrance.fr
