Porpidinia brevispora, a new species and the second representative of the genus Porpidinia (Lecideaceae, Lecanorales) from the Russian Far East

Abstract

Porpidinia brevispora sp. nov. from Shikhote-Alin Range, Primorye Territory, Russian Far East is described and illustrated. The new species resembles Porpidinia tumidula morphologically, but is distinct in its spherical to ellipsoid, significantly smaller ascospores that do not overlap in size with those of P. tumidula, as well as a lower hymenium with paraphyses embedded into hyaline gelatinous envelopes, up to 5 µm wide. Porpidinia brevispora inhabits carbonate rocks at low elevations.

Full text

Phytotaxa 459 (1): 075–080
https://www.mapress.com/j/pt/
Copyright © 2020 Magnolia Press Article PHYTOTAXA
ISSN 1179-3155 (print edition)
ISSN 1179-3163 (online edition)
Accepted by Christian Printzen: 29 Aug. 2020; published: 9 Sept. 2020
https://doi.org/10.11646/phytotaxa.459.1.8
75
Porpidinia brevispora, a new species and the second representative of the genus
Porpidinia (Lecideaceae, Lecanorales) from the Russian Far East
LIDIA YAKOVCHENKO1,5, EVGENY A. DAVYDOV2,6*, ALEXANDER PAUKOV3,7 & YOSHIHITO
OHMURA4,8
1 Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS, 100th anniversary of Vladivostok Avenue, 159, Vladivostok
690022, Russian Federation.
2 Altai State University, Lenin Ave. 61, 656049 Barnaul, Russia.
3 Institute of Natural Sciences and Mathematics, Department of Biology, Ural Federal University, Lenin Ave., 51, 620000 Ekaterinburg,
Russia.
4 National Museum of Nature and Science, Tokyo, Amakubo 4-1-1, Tsukuba city, 305-0005 Japan.
5
�
lidiyakovchenko@mail.ru; https://orcid.org/0000-0002-4342-7771
6
�
eadavydov@yandex.ru; https://orcid.org/0000-0002-2316-8506
7
�
alexander_paukov@mail.ru; https://orcid.org/0000-0001-6689-7189
8
�
ohmura-y@kahaku.go.jp; https://orcid.org/0000-0003-2557-2761
Abstract
Porpidinia brevispora sp. nov. from Shikhote-Alin Range, Primorye Territory, Russian Far East is described and illustrated.
The new species resembles Porpidinia tumidula morphologically, but is distinct in its spherical to ellipsoid, significantly
smaller ascospores that do not overlap in size with those of P. tumidula, as well as a lower hymenium with paraphyses
embedded into hyaline gelatinous envelopes, up to 5 µm wide. Porpidinia brevispora inhabits carbonate rocks at low
elevations.
Keywords: new taxa, East Asia, Porpidinia tumidula, calciphilous lichen, Shikhote-Alin Range, squamulose growth form
Introduction
The genus Porpidinia was established by Timdal (2010) to accommodate Porpidinia tumidula (Sm.) Timdal, a species
previously placed in Toninia due to its thallus organization but which did not fit the concept of Toninia in having
Psora-type asci, non-amyloid hymenial gelatin and more closely conglutinated paraphyses with a sharply delimited
pigmented cap. In contrast, Toninia s. str. has Bacidia-type asci, amyloid hymenial gelatin and weakly conglutinated
paraphyses with diffusely pigmented tips (Timdal 1991, 2010). Porpidinia also resembled Psora, but differs from the
Psoraceae in having a well-developed, deeply pigmented proper exciple, more loosely conglutinated paraphyses with a
more sharply delimited pigment cap, and a non-amyloid hymenial gelatin (Timdal 2010), and according to recent data
belong to Lecideaceae (Lücking et al. 2017). Porpidinia differs from the squamulose genus Romjularia (Lecideaceae)
in black (not dark brown) apothecia, non-amyloid hymenial gelatin, a dark brown (not pale brown) hypothecium and
paraphyses with swollen apical cells.
Porpidinia is characterized by an irregular squamulose thallus composed of large (up to 8 mm in diam.), roundish
to lobate, ±convex, pale greenish gray to pale olive-brown squamules with a dense white pruina (rarely epruinose),
brown-black to black, marginal lecideine apothecia, a brown K–, N– epihymenium, a dark-brown hypothecium and an
exciple with calcium oxalate crystals, closely agglutinated paraphyses with swollen brown-pigmented tips, 8-spored
asci of the Psora-type, and colourless, simple to 1-septate, narrowly ellipsoid ascospores, (10–)12–16(–18) × 3–5
μm. (Bredkina et al. 2003, Hitch et al. 2009, Timdal 2010, Wirth et al. 2013) The thalli contained either no lichen
substances or an unknown UV+ blue substance (Timdal 2010).
Porpidinia tumidula inhabits exposed calcareous rocks in a wide range of habitats from maritime to montane
zones (Timdal 2010, Wirth et al. 2013). It is widely distributed in southern Europe and is also reported from central,
western and northern Europe, northern Africa (Algeria), Asia (Russian part of Caucasus) and New Zealand (Galloway
2007, Hitch et al. 2009, Timdal 2010, Wirth et al. 2013, Urbanavichus & Ismailov 2016).

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76 • Phytotaxa 459 (1) © 2020 Magnolia Press
A putative new species of Porpidinia was collected several times from carbonate rocks in the southern part of
the Sikhote-Alin Range, which is located in a fairly isolated part of the Primorye Territory. The largest massifs of
the central Sikhote-Alin are located in the vicinity of Dal’negorsk. This is an almost continuous massif of limestone
covered by a mixed forest, with prominent, exposed steep rocks. The total length of the massif is about 4 km with the
maximum elevation ca. 600 m. Separate limestone outcrops with an elevation ca. 300 m are located in the vicinity
of Kavalerovo, ca. 65 km to the south-west from Dal’negorsk. This second species of the genus is described here.
Morphologically it resembles Porpidinia tumidula, but is distinguished by its almost spherical to ellipsoid, significantly
smaller ascospores and its thinner hymenium with paraphyses embedded in hyaline, gelatinous envelopes to 5 µm
wide. Porpidinia brevispora inhabits carbonate rocks at low elevations.
Material and methods
The material studied comprised eight specimens of Porpidinia brevispora collected in 2011 and 2017 from limestone
outcrops in the lowlands of the central Sikhote-Alin Range. Two exsiccata and one other collection of Porpidinia
tumidula from Europe, which were received on loan from the herbarium of the Komarov Botanical Institute, Saint
Petersburg (LE) were also studied. Herbarium specimens were examined using a stereomicroscope (Zeiss Stemi 2000-
C) and a compound microscope (Zeiss Axio Lab.A1). Anatomical examination was undertaken using hand-cut sections
mounted in water with following reagents (R): 10% KOH (K), 10% HNO3 (N), lactophenol cotton blue (LCB) and
Lugol’s solution (I). Polarized light (pol) was used for locating crystals in the sections. Measurements of ascospores,
apothecia, squamules and hymenium are presented as follows: (smallest value recorded) (X-SE)–X–(X+SE) (largest
value recorded), where X is the (arithmetic) sample mean, and SE is the sample error of mean. Other measurements
are presented as (extreme minimum) minimum‒maximum (extreme maximum). The measurements of anatomical
structures were made to the nearest 0.5 μm. Lichen substances were examined using thin layer chromatography (TLC)
with solvent systems B’ (hexane: methyl tert-butyl ether: formic acid, 140: 72: 18) and C (toluene : acetic acid = 170 :
30) following Orange et al. (2001).
Results
Porpidinia brevispora Yakovchenko & Davydov, sp. nov. (Figure 1A–E)
MycoBank No.: MB 835375
Thallus squamulose. Apothecia lecideine, black, located on the margins of the squamules. Hypothecium and exciple
dark brown. Hymenium not amyloid; paraphyses embedded in gelatinous envelopes, agglutinated, brown at the
tips. Asci clavate, 8-spored, of the Psora-type; ascospores spherical, ovoid to ellipsoid, (5.5–)7.0–8.0–9.0(–9.5) ×
(3.5–)4.0–4.5–5.0(–5.0) µm. Similar to Porpidinia tumidula but differing by its spherical to ellipsoid, significantly smaller ascospores
and the thinner hymenium with paraphyses embedded in hyaline gelatinous envelopes to 5 µm wide.
Type:—RUSSIA, Primorye Territory: Kavalerovskiy District: to S from Kavalerovo settlement, eastern macroslope of central Sikhote-
Alin Range, at the right bank of the Zerkal’naya River, 44°14′50″N, 135°03′38.5″E, elev. 290 m, near the summit of a calcareous
cliff surrounded by a polydominant broadleaf deciduous forest, on calcareous rocks, 1 September 2017, E.A. Davydov 19340 & L.S.
Yakovchenko (holotype, LE–L15308, isotype, O).
Thallus squamulose, irregular, to 7 cm in diameter, without a hypothallus, R–. Squamules (0.5–)1.3–2.0–2.6(–4.0) mm
diam. (n=130), scattered to continuous or partially overlapping, rounded to lobed or partly angular if crowded, flattened
to convex or bullate, to 0.8 (–1.0) mm thick. Upper surface white, pale greenish grey to pale grey-olive, dull, rough
to heavy fissured, pruinose at least along the margins, often entirely densely pruinose. Margins swollen if squamules
flattened, concolorous with the upper surface to paler, often with finely grained white pruina. Vegetative propagules,
pores and pseudocyphellae absent. Medulla white, non-amyloid. Lower surface pale brown with concolorous
root-like holdfasts at the base. Upper cortex 45–70 µm high (n=15), colourless, brownish above, sometimes with
an epinecral layer, composed of anticlinally arranged, thick-walled hyphae with shortly cylindrical lumina, densely
inspersed with calcium oxalate crystals. Algal layer continuous, 50–80 µm high (n=15); algae chlorococcoid, to 15
µm in diam. Medulla grey, opaque, with a poorly distinguishable structure. Lower cortex dark brown, extending

A NEW SPECIES OF PORPIDINIA BREVISPORA Phytotaxa 459 (1) © 2020 Magnolia Press • 77
FIGURE 1. Porpidinia brevispora (holotype): (A) holotype specimen (LE–L15308); (B) section of thallus; (C) section of apothecium;
(D) asci and paraphyses with caps and thick gelatinose envelopes, in lactophenol cotton blue; (E) ascospores. Bars: A=2 mm; B&C=50
µm; D=20 µm; E=10 µm.

YAKOVCHENKO ET AL.
78 • Phytotaxa 459 (1) © 2020 Magnolia Press
beyond the borders of the squamules and forming a rim to 40 µm thick, poorly developed at the base. Apothecia
usually present, marginal, (0.2–)0.6–0.8–1.0(–1.6) mm diam. (n=137), lecideine, single, rarely confluent, 1–3 per
squamule, rounded, sessile, widely attached to slightly constricted at the base. Disc black, flat to convex, matt, smooth,
epruinose. Proper margin black, to 0.1 mm thick, even, matt to slightly shiny, at the same level as the disc or becoming
excluded with age. Hymenium (45.0–)50.0–54.0–57.0(–60.0) µm thick (n=20), hyaline. Epihymenium olive-brown,
K–, N–. Hypothecium poorly discernable from the proper exciple, dark brown, without crystals. Proper exciple dark
red-brown, in the uppermost part sometimes greyish brown, fan-shaped, expanding at the margin to 150 µm thick,
composed of conglutinated, thick-walled hyphae with angular to narrowly cylindrical lumina, 5–15 × 2.5–4 µm (n=20),
without crystals (pol–). Paraphyses septate, simple to branched or anastomosed, closely coherent even in K, 2.0–2.5
µm (n=20), with a hyaline, gelatinous envelope to 5 µm wide in the middle part of the hymenium; apical cells to 5 µm
wide, with brown gelatinous caps. Asci 8-spored, clavate, 37.5–50.0 × 9.0–12.0 µm (n=20), with a well-developed,
amyloid tholus containing an indistinct darker amyloid tube most pronounced in the upper part. Ascospores simple,
hyaline, spherical to ovoid to ellipsoid, rounded to somewhat pointed at one or both ends, (5.5–)7.0–8.0–9.0(–9.5) ×
(3.5–)4.0–4.5–5.0(–5.0) µm (n=70). Pycnidia not found.
Chemistry: no lichen substances detected by TLC; medulla and cortex K–, KC–, C–, Pd–, I–.
Etymology: The name refers to the small size of ascospores, an essential character distinguishing this species
from its closest relative, Porpidinia tumidula.
Ecology: Porpidinia brevispora grows exposed, sunny calcareous rocks, often in shallow fissures. It is rarely found
in more shaded conditions, such as in limestone caves and on rocks in the forest. The species is found at elevations
of 290−570 m. Due to the large size of thalli, Porpidinia brevispora is a dominant species in lichen associations on
rocky surfaces. It commonly grows together with representatives of the Verrucariaceae and Lichinaceae. Associated
species include Endocarpon pusillum Hedw., Placynthium nigrum (Huds.) Gray, Protoblastenia calva (Dicks.) Zahlbr.,
Psorotichia shaereri (A. Massal.) Arnold, and Verricaria nigrescens Pers.
Distribution: The species is so far known from only five localities on the eastern macroslope of the central
Sikhote-Alin Range, which belong to two administrative districts of the Primorye territory (Russian Far East). The
distance between the most remote localities is ca. 75 km.
Additional specimens of Porpidinia brevispora examined: RUSSIA, Primorye Territory: Dalnegorskiy district,
eastern macroslope of Sikhote-Alin Range: at 6.5 km NE from Dal’negorsk toward to Cheremshany settlement,
Gorbusha River valley (Rudnaya River’s basin), 44°37′01.4″N, 135°39′26.3″E, elev. 349 m, limestone cave at
the top of the mountain, on calcareous rocks, 16 September 2011, L.S. Yakovchenko 1206 (herbarium Davydov &
Yakovchenko); ibid., at 3 km NW from Dal’negorsk, upstream the Barachnyi Stream, 44°34′55″N, 135°33′10″E,
elev. 480 m, polydominant mixed forest with a calcareous rocks massif, on calcareous rocks, 2 September 2017, E.A.
Davydov 19314 & L.S. Yakovchenko (H, herbarium Davydov & Yakovchenko); ibid., at 3.5 km NW from Dal’negorsk,
upstream the Barachnyi Stream, polydominant broadleaf deciduous forest, 44°35′21″N, 135°33′15″E, elev. 570
m, S exposed carbonate cliff, on calcareous rocks, 3 September 2017, E.A. Davydov 19365 & L.S. Yakovchenko
(O, herbarium Davydov & Yakovchenko); ibid., at 3.5 km NW from Dal’negorsk, upstream the Barachnyi Stream,
polydominant broadleaf deciduous forest, 44°35′19″N, 135°33′12″E, elev. 550 m, carbonate rock in the forest, on
calcareous rocks, 3 September 2017, E.A. Davydov 19346 & L.S. Yakovchenko (herbarium Davydov & Yakovchenko);
ibid., at 3.5 km NW from Dal’negorsk, upstream the Barachnyi Stream, polydominant broadleaf decideous forest,
44°35′19″N, 135°33′12″E, elev. 550 m, S exposed limestone massif, on calcareous rocks, 3 September 2017, E.A.
Davydov 19350 & L.S. Yakovchenko (FR).
The examined specimens of Porpidinia tumidula fits well to the descriptions given in the literature (Bredkina et
al. 2003, Hitch et al. 2009, Timdal 2010, Wirth et al. 2013), however some characters were not discussed before, but
seem to be diagnostically important. Margin of squamules not swollen, concolorous with the upper surface to paler,
epruinose. Paraphyses without a hyaline gelatinous cover (Fig. 2A)
Specimens of Porpidinia tumidula examined: [ITALY], Massalongo, Lich. Exs. Ital. 29 (LE), [AUSTRIA], Hertel,
Lich. Alp. 105 (LE); Kalenderberg bei Mödling nächst Wien. 20 October 1867 (LE ex. Herb. Eggerth).
Discussion
The differences between P. brevispora and its closest relative, P. tumidula, based on the available descriptions (Bredkina
et al. 2003, Hitch et al. 2009, Timdal 2010, Wirth et al. 2013), and our own examination of the loaned specimens, are
given in the Table 1.

A NEW SPECIES OF PORPIDINIA BREVISPORA Phytotaxa 459 (1) © 2020 Magnolia Press • 79
TABLE 1. The diagnostic characters of Porpidinia brevispora and P. tumidula.
Character P. brevispora P. tumidula
Thallus size of squamules to 2.6 (–4.0) mm diam. to 6 (–8) mm diam.
margin of squamules
swollen in flattened squamules; with
a fine-grained white pruina, rarely
epruinose
not swollen; epruinose
presence and location of pruina entirely heavily pruinose or pruinose
at least along the margins not pruinose to weakly pruinose
chemistry no lichen substance
no lichen substances or an unknown
UV+ blue substance with Rf values
similar to those of atranorin
Apothecia colour black brown-black to black
glossiness dull with a shiny to dull proper margin shiny
crystals in the proper exciple absent present
hymenium height 45–60 µm 67–80 µm
Paraphyses
2.0–2.5 µm in the midhymenium with
hyaline gelatinous envelopes, to 5 µm
wide; tips up to 5 µm wide
to 2.5(–3) µm in the midhymenium,
without hyaline gelatinous envelopes;
tips to 6 µm wide
ascospores shape simple, spherical to ovoid, broadly
ellipsoid, and ellipsoid
simple to 1-septate, narrowly ellipsoid
to ellipsoid
ascospores size (5.5–)7.0–8.0–9.0(–9.5) × (3.5–)4.0–
4.5–5.0(–5.0) µm (10–)12–16(–18) × 3–5 μm
FIGURE 2. Porpidinia tumidula: (A) asci and paraphyses without thick gelatinose envelopes, in lactophenol cotton blue; (B) ascospores.
Bars: A=20 µm; B=10 µm.

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80 • Phytotaxa 459 (1) © 2020 Magnolia Press
The range of ascospore sizes of Porpidinia tumidula given in the literature was found to be a little higher than the
variation observed by us, i.e 12–18 × 4–5 μm: “simple, narrowly-ellipsoid” (Timdal 2010, With et al. 2013), 10–16 ×
3–5 μm: “simple to one-septeted, ellipsoid” (Bredkina et al. 2003, Hitch et al. 2009). The presence of atranorin (thallus
K+ yellow) was reported for P. tumidula (Timdal 1991, Bredkina et al. 2003) but later refuted (Timdal 2010, Wirth et
al. 2013).
The two species of Porpidinia are very similar morphologically. Although the maximum size of squamules of
Porpidinia tumidula is twice that of those of P. brevispora, this character is not diagnostic because the average size
of squamules of both species overlaps. The size of the apothecia in both species is also the same. An additional
morphological trait which is usually observed in P. brevispora is the presence of swollen margins, usually covered
by a fine-grained white pruina (better seen in young squamules). This trait seems to be useful in distinguishing
sterile specimens. However, the unequivocal feature for separating these two species is the size and the shape of the
ascospores: spherical to ovoid and broadly ellipsoid, 5.5–9.5 × 3.5–5 μm in P. brevispora (Fig. 1E), and narrowly
ellipsoid, 10–18.0 × 3–5 μm in P. tumidula (Fig. 2B). Ellipsoid ascospores are known in both species but they are
smaller in P. brevispora and the sizes never overlap. Additional characters which distinguish P. brevispora from P.
tumidula are the lower hymenium, the absence of crystals in the exciple, the paraphyses embedded in a gelatinous
sheath throughout their entire length. Both species have similar ecological preferences, inhabiting calcareous montane
rocks. Their geographical distributions do not overlap: P. brevispora is so far known from the East Asia only, whereas
P. tumidula occurs in Europe, North Africa, Asia (Caucasus), and New Zealand. The New Zealand records are unusual
and invite further scrutiny.
Acknowledgements
The study of LY was carried out within the framework of the institutional research project no. AAAA-A17-
117062710098-4 of the Federal Scientific Center of the East Asia Terrestrial Biodiversity FEB RAS.
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