Content uploaded by Georgi Kunev
Author content
All content in this area was uploaded by Georgi Kunev on Jul 19, 2022
Content may be subject to copyright.
On the occurrence of Anogramma leptophylla in Bulgaria
Georgi Kunev1*, Krasimir Lakovski
1Department of Botany, Faculty of Biology, Sofia University “St. Kliment Ohridski”,
8 “Dragan Tzankov” Blvd., Sofia 1164, Bulgaria, e-mail: *gikunev@uni-sofia.bg
14TH SYMPOSIUM ON THE FLORA
OF SOUTHEASTERN SERBIA AND
NEIGHBORING REGIONS
26-29.06.2022, Kladovo, Serbia
Introduction
During the early vegetation season of 2022, we have found Anogramma leptophylla
(Pteridaceae) on the territory of Bulgaria, in two localities and about twenty
microsites. No herbarium materials of the species previously collected in Bulgaria
were found in the national indexed herbaria SO, SOM and SOA, nor any historical
records were traced back in the major floristic references on Bulgarian flora
(Ahtarov & Yordanov 1963; Assyov & Petrova 2012; Stoyanov & al.2021). Evidently,
this is the first registered find of the species in the country. With the current
presentation, we provide information on the species overall morphology, based on
collected specimens, SEM morphograps of spores and sporangia, phenology,
distribution and habitat characteristics, and provisional threatened status based on
the IUCN criteria.
Species description
Anogramma leptophylla is a fern species with unusual lifecycle. The sporophyte may live for a
few months, i.e. dies annually, while the gametophyte may stay perennial as dormant
underground tubercles. The fronds are dimorphic. First fronds that appeared during the season
(Fig. 1) are shorter, petioles up to 1-1.5 cm, lamina 2-3 cm, fan-shaped, deeply lobed, pinnae
broader, pinnules obovate at tips, mostly sterile. Secondary (fertile) fronds (Fig. 2) are taller, 3-8
(-12)cm, petioles 2-5 cm, lamina 3-7 cm, pale green, membranous, bi-or tripinnate, pinnae
narrower, pinnules obtuse-acute at tips, early in the season their margins are convolute to cover
immature sporangia (Fig. 3), sori oblong-linear, exindusiate, developed along dichotomously
brunched veins (Fig. 5). Sporangia are more or less spherical, variable in size, short stalked, 220-
310 µm in length (stalk included) (Fig. 13). Spores are brown to dark-brown, tetrahedral-
hemispherical in equatorial view, equatorial diameter is (45)-45.9-(48.1) µm (Figs. 11-12). The
data on spore morphology and measures correspond well to those presented by Vaganov & al.,
2017 for A. leptophylla from South-West Asia. Chromosome number n=26 (Rasbach & Reichstein
1990); n=29,58 (Tryon 1990). Materials from Bulgaria were not subject of chromosome count. Chronology of fieldwork with phenological observation on the species
1) The first observation of A. leptophylla was made by the first author, on 16.02.2022,on the slopes of ‘Skalata’height,
the Struma Valley (Southern), Blagoevgrad District, on the ground, under rock ledges, and in niches, at 120 m alt. At
this particular microsite, numerous gametophytes and about 80 sporophytes were noticed. Sporophytes were mostly
juvenile, with fertile fronds just starting to emerge (Fig. 1). No sporangia were observed at that date. 2) On
25.03.2022, the observed plants were bearing not fully developed fertile fronds with immature sporangia (Figs. 2-3).
Two more microsites were located on the slopes of 'Skalata' height with not more than 10 individuals at a spot. 3) On
23.04.2022 a third trip was taken on. The observed plants were in final stage of development of their sporangia, which
were mostly matured, dark-brown or blackish and ready for spore dispersal. Several individuals were collected, from
which latter spores for SEM examinations were extracted (materials at SO 108162 and SOM 177701) (Figs 4-5; 7-13).
More sites of the species were located on the neighboring ‘Pchelina’height, about 3.6 km in south direction from the
first observed locality. 4) On 28.04.2022, the second author observed the species on even more sites in both locations.
With the addition of these findings, the microsites of A. leptophylla reached 20 (Fig. 14), with about 1000 individuals
overall. This shows that the species has stable populations and it is perhaps distributed on the neighboring heights,
which however have been not investigated by us. During the last two field excursions, the sterile leaves on most of the
observed individuals of the species were withered or completely dried. However, in some individuals we have
observed well-developed sporangia on the ventral side of the so-called 'sterile' fronds, although less in number
comparing with the fertile fronds of the same individuals (Fig. 10). 5) On 19.06.2022, the individuals of the species at
‘Pchelina’height were completely dried with open sporangia and some spore still attached on the frond surface.
Therefore, it could be conclude that the aboveground phase of the lifecycle of A. leptophylla in Bulgarian populations
of the species completes in about 6 months - December-May.
Distribution and habitat
The species has been observed on steep, rocky slopes with inclination of about 40°.The
microsites are situated mostly at the base of tall rocks, under rock ledges, in niches or rarely in
аshallow negative topographic forms, in more or less shaded spots. Plants grow mostly from
soil or fine debris composed of sand, gravel particles and dried organic matter. Microsites
most often face West, Southwest or Northwest. The climate is of transitional Mediterranean
type, with mean annual temperature 15.2 °C, average temperature for the coldest month
(January) of 3.5°C and precipitation maximum during winter months (Climate-Data 2022). A.
leptophylla is an Atlantic-Mediterranean element, found in regions with high rainfall and
relative humidity. The Struma River and closely located hot thermal spring at ‘Rupite’locality
provide the required level of humidity for the growth of the species at the reported sites. The
species is noncompetitive and occupies pioneer sites. It grows solitary or it is associate with
other weak competitors, mostly annuals. The species composition at the localities includes
Teesdalia coronopifolia,Viola kitaibeliana,Asterolinon linum-stellatum,Crepis sancta,
Hypochaeris glabra,Umbilicus rupestris,Fumaria officinalis,F. rostellata,Myosotis
ramosissima,Cardamine hirsuta,Galium aparine,Spergula pentandra,Vulpia ciliata,Tolpis
umbellata,Aira elegantissima,Psilurus incurvus,Micropyrum tenellum,Filago arvensis, etc.
16.02.2022
Fig. 1 25.03.2022 25.03.2022
Fig. 2Fig. 3
Fig. 4Fig. 6Fig. 5
23.04.2022 23.04.2022
28.04.2022
km2(2 grid squares 2x2 km), therefore the species responds against criteria B1 and B2 as aCritically Endangered and
as Endangered against criterion D. Considering the historical records (SOA 000162, Stoyanov 1921; Micevski 1985) for
the species from the closely situated Belasitsa Mt (Mt Kerkini in Greece) and the availability of adequate habitats in
the neighboring heights ‘Byalata kashta’and ‘Kosmatitsa’(Fig.14), we propose provisional threatened status of A.
leptophylla in Bulgaria as Vulnerable.If more locations are found in following years the species than it would be better
down-listed to Nearly Threatened. (IUCN 2012). We recognized shrub encroachment as most serious threat for the
species in Bulgaria. This is especially true for the northern and northwestern slopes of the 'Skalata' height, where
Crataegus monogyna,Pyrus pyraster,P. amygdaliformis,Paliurus spina-christi,Prunus spinosa,Rubus spp. overgrow
upon significant areas. Moderate grazing of goats would stabilize this process and open up the grass-shrub coenoses
to establish suitable pioneer sites for A. leptophylla.
Conservation status and threats
A. leptophylla is a species evaluated as aLeast
Concern on European scale (Garcia Criado & al.
2017). However, it is impossible to evaluate the
status of the species at a regional scale, because not
all of the IUCN criteria could be applied at present
level of knowledge for its population trends in
Bulgaria. Currently two subpopulation with overall
20 microsites and up to 1000 individuals were
observed in the country. The ‘Extent of occurrence'
(EOO) is 0.8 km2and ‘Area of occupancy’ (AOO) is 8
Fig. 7Fig. 8 Fig. 9Fig. 10
Fig. 11 Fig. 12 Fig. 13
Fig. 14
References:
Ahtarov, B., & Yordanov, D. 1963: Pteridophyta. In: Jordanov, D. (ed.), Flora Reipublicae Popularis Bulgaricae, vol. 1, 82–144.In Aedibus Academiae Scientiarum Bulgaricae, Serdicae (in Bulgarian).
Assyov, B., Petrova, A. (eds.), 2012: Conspectus of the Bulgarian vascular flora. Distribution maps and floristic elements, ed. 4. BBF, Sofia.
Garcia Criado & al.2017: European red list of lycopods and ferns.
IUCN 2012: Guidelines for Application of IUCN Red List Criteria at Regional and National Levels, Version 4.0. Gland, Switzerland and Cambridge, UK
Micevski, K., 1985: Flora of FR Macedonia. 1/1, 52. Makedonska akademija na naukite umetnostite, Skopje (in Macedonian).
Nakazato, T., & Gastony, G. J. 2003: Molecular phylogenetics of Anogramma species and related genera (Pteridaceae: Taenitidoideae). Systematic Botany, 28(3), 490-502.
Rasbach, H., & Reichstein, T. 1990: The chromosome number of Anogramma leptophylla (Adiantaceae: Pteridophyta) from Europe. Fern Gaz, 13(6), 341-348.
Stoyanov, K., Raycheva Ts. & Cheschmedzhiev I. 2021: Key to the native and foreign vascular plants in Bulgaria. Agricultural University Plovdiv Academic Press (in Bulgarian).
Stoyanov, N. 1921: Floristic materials from Mt Belasitsa. Ann. of Sofia Univ. “St. Kliment Ohridski”, (in Bulgarian).
Tryon, R. M. 1990): Pteridaceae. In: Pteridophytes and gymnosperms, 230-256. Springer, Berlin, Heidelberg.
Vaganov, A. V., Gureyeva, I. I., Kuznetsov, A. A., Shmakov, A. I., & Romanets, R. S. 2017: Data on spore morphology of Cerosora microphylla (Anogramma microphylla)(Pteridaceae). Biosystems
Diversity, 25(2), 141-144.
Zhang, L., Zhou, X. M., Lu, N. T., & Zhang, L. B. 2017: Phylogeny of the fern subfamily Pteridoideae (Pteridaceae; Pteridophyta), with the description of a new genus: Gastoniella. Molecular
Phylogenetics and Evolution, 109,59-72.