Notes on lichenicolous Pleosporales, with two new species, Didymocyrtis azorica and Pseudopyrenidium epipertusariae (Phaeosphaeriaceae)
Author
Etayo, J.
Navarro Villoslada 16, 3 º dcha. 31003 Pamplona, Navarra, Spain.
Author
Pino-Bodas, R.
Royal Botanic Gardens, Kew, Richmond, Surrey, TW 9 3 DS, UK.
text
Phytotaxa
2021
2021-03-31
494
1
75
88
http://dx.doi.org/10.11646/phytotaxa.494.1.4
journal article
10.11646/phytotaxa.494.1.4
1179-3163
5423306
Didymocyrtis azorica
Etayo & Pino-Bodas
,
sp. nov.
(
Fig 4
)
Mycobank MB 838957
Diagnosis: Similar to
Didymocyrtis micropunctum
but this species has completely immersed ascomata, larger spores, 10.5–15 x 4–6 µm, with verruculose, not striate ornamentation. Furthermore, the
type
host of
D. micropunctum
is
Parmotrema
.
Type
:—
PORTUGAL
.
The
Azores
,
Terceira
,
Reserva Nacional Serra de Santa Barbara
, volcanic domes of
Misterios Negros
,
Lagoa do Negro
, on thallus of
Hypotrachyna rockii
(Zahlbr.) Hale
on mossy branches of laurisilva trees,
600–650 m
,
38º44’01’’N
,
27º17’05’’W
,
22 July 2017
,
J
. Etayo
30968 (PO-holotypus, hb. Etayo-isotypus)
.
FIGURE 4.
Didymocyrtis azorica
sp. nov.
(holotypus). A, B, habitus with immersed perithecia on
Hypotrachyna
thallus mixed with other smaller structures less developed. C, ascus and paraphyses (KI). D, E, H, asci (water). F, G, ascospores ornamented with striation subparallel with the large sporal axe. Scales A, B = 100 µm; C, E, F, G, H = 10 µm; D = 50 µm.
Ascomata perithecioid, black, immersed, subglobose, 90–120 µm diam., grouped but not confluent, mature mixed or not with younger ones or bad developed ones much more abundant. Ascomatal wall formed by thin, branched hyphae with thin wall, brown color, K+ greenish black, 1.5–2 µm thick surrounded by an extracellular pigment forming clusters. Hymenium I-, KI-. Paraphyses abundant, very thin, near 1 µm wide, branched-anastomosed, not capitated. Asci cylindrical, 8-spored, widened apically, KI-; epiplasm I, KI+ orange color, 58–73 × 6.5–8 µm. Ascospores brown, 1-septate, not constricted in the septum, with obtuse apex or, more frequently, slightly papillate in the apex, with a large oil guttule by cell, rarely two, with ornamented surface, striate around parallely to the long axe, (7.5–)8–9(–11) × 4.5–5.5 µm, without sheath when young.
Host and distribution: It is known only from Terceira where it has been collected in two localities on
Hypotrachyna rockii
.
Discussion: The most similar described species is
D. micropunctum
Etayo (2017: 176)
, reported on
Parmotrema
from
Ecuador
. This has larger spores 10.5–15 × 4–6 μm with not striate but verruculose surface. Its habitus is also different,
D. micropunctum
has perithecia completely sunken in the host thallus and they are difficult to see, while in
D. azorica
perithecia are more visible and intermixed with young or poorly developed ones. Furthermore,
D. azorica
has ascomata covered by thin and brown hyphae, K+ greenish black.
Polycoccum montis-wilhelmii
Diederich
in Aptroot
et. al.
(1997: 141), whose
type
was also collected on
Hypotrachyna
, is distinguished by its shorter and wider asci, 47–60 × 12–15 µm and larger ascospores 14.5–16 × 6.5–7 µm, with verruculose surface and with a thin sheath amongst other differences. Finally,
Didymocyrtis melanelixiae
has also been recorded on
Hypotrachyna
from
UK
(ERTZ
et al.
2015). This species differs from
D. azorica
in its larger perithecia (200–250 µm diam.), larger asci (70–100 x 7.5–10.5 µm and larger spores (11.5–15 x 4–5.5 µm) that are (1–)2(–3) septate with verruculose ornamentation (ERTZ
et al.
2015).
Additional studied specimens:
PORTUGAL
. The
Azores
: Terceira, Malha Grande, trail Rocha do Chambre, cresta ventosa, on
Hypotrachyna rockii
on big
Erica azorica
,
510 m
,
38º45’02’’N
,
27º15’08’’W
,
24 July 2017
,
J. Etayo
31009 (hb. Etayo).