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РОССИЙСКАЯ АКАДЕМИЯ НАУК БОТАНИЧЕСКИЙ ИНСТИТУТ им. В. Л. КОМАРОВА
ACADEMIA SCIENTIARUM ROSSICA INSTITUTUM BOTANICUM NOMINE V. L. KOMAROVII
НОВОСТИ СИСТЕМАТИКИ НИЗШИХ РАСТЕНИЙ
ТОМ 46
NOVITATES SYSTEMATICAE PLANTARUM NON VASCULARIUM
TOMUS XLVI
Ботанический институт им. В. Л. Комарова РАН Санкт-Петербург 2012
Новости систематики низших растений. Том 46, 2012
Alexey D. Potemkin1 Teuvo Ahti2
А. Д. Потёмкин Т. Ахти
ON RICCIA MARGINATA AND RELATED SPECIES (RICCIACEAE, MARCHANTIOPHYTA)
О RICCIA MARGINATA И РОДСТВЕННЫХ ВИДАХ (RICCIACEAE, MARCHANTIOPHYTA)
1 Laboratory of Lichenology and Bryology Komarov Botanical Institute RAS 2 Professor Popov Str., St. Petersburg, 197376 Russia Potemkin_alexey@mail.ru 2 Botanical Museum Finnish Museum of Natural History P.O. Box 7, FI-00014 University of Helsinki Finland Teuvo.Ahti@helsinki.fi
Riccia marginata Lindb. was described by S. O. Lindberg (1877) from the outskirts of the town of Sortavala near the north shore of Lake Ladoga, Republic of Karelia, Russia. The species has been forgotten in most recent liverwort accounts of Europe, including Russia. Lectotypification of R. marginata is provided. R. marginata shares most characters with R. beyrichiana Hampe ex Lehm. It differs from «typical» plants of R. beyrichiana in having smaller spores, with ± distinctly finely areolate to roughly papillose proximal surfaces and a narrower and shorter thallus, as well as in scarcity or absence of marginal hairs. It may represent continental populations of the suboceanic-submediterranean R. beyrichiana, known in Russia from the Leningrad Region and Karelia only. The variability of spore surfaces in R. beyrichiana is discussed and illustrated by SEM images. A comparison with the spores of R. bifurca Hoffm. is provided. The question how distinct R. marginata is from R. beyrichiana needs to be clarified by molecular studies in the future, when adequate material is available. R. marginata is for the time being, provisionally, included in R. beyrichiana.
Keywords: nomenclature, lectotypification, taxonomy, Riccia marginata, Riccia beyrichiana, Riccia lescuriana var. glaucescens, Riccia bifurca, spores.
Riccia marginata Lindb. была описана S. O. Lindberg (1877) из окрестностей г. Сортавала, находящегося на северном берегу Ладожского озера в Республике Карелия. Вид был пропущен во всех современных сводках по печеночникам Европы и России. На основании изучения синтипа и оригинального описания проведена лектотипификация R. marginata. R. marginata по большинству признаков сходна с R. beyrichiana Hampe ex Lehm., от «типичных» растений которой отличается более мелкими спорами с более или менее явной мелкоячеистой или продолговатобугорчатой в зрелом состоянии структурой проксимальной поверхности, более узким слоевищем и едва развитыми или отсутствующими ресничками. R. marginata может представлять континентальные популяции
R. beyrichiana, известной в России только из Ленинградкой области и Карелии. Рассмотрена и проиллюстрирована (SEM) изменчивость структуры спор R. marginata и R. beyrichiana. Проведено сравнение со спорами R. bifurca Hoffm. Степень таксономической обособленности R. marginata от R. beyrichiana может быть выяснена посредством молекулярных исследований при наличии достаточного материала. В настоящее время R. marginata рассматривается как провизорный синоним R. beyrichiana.
Ключевые слова: номенклатура, лектотипификация, таксономия, Riccia marginata, Riccia beyrichiana, Riccia lescuriana var. glaucescens, Riccia bifurca, споры.
During the work on the liverwort collections in the Herbarium of Sex-tus Otto Lindberg, Botanical Museum, University of Helsinki (H-SOL), it was discovered that Riccia marginata Lindb., described from the territory of the Republic of Karelia, was not mentioned in Russian liverwort accounts (Savicz, Ladyzhenskaya, 1936; Schljakov, 1982; Konstantinova, Potemkin, Schljakov, 1992; Konstantinova, Bakalin et al., 2009[2010]; Potemkin, Sofronova, 2009).
This species was not at all listed in most treatments of Scandinavian liverworts (Jergensen, 1934; Buch, 1936; Koponen et al., 1977; Damsholt, 2002) either, and is not represented in the Index Hepati-carum Names Database. However, it was mentioned by J. P. Norrlin (1878: 22) and listed as a synonym of R. beyrichiana Hampe ex Lehm. in К. Muller's (1905-1916, 1951-1958) treatment of European and S. Arnell's (1956) treatment of Fennoscandian liverworts. In Muller's flora (l. c.) it was listed as R. marginata Lindb. msc.! A reference to the original description of R. marginata is provided only in Arnell (1956), Index Hepaticarum volume 12 (Geissler, Bischler, 1990) and «Tropicos Database».
Original description of Riccia marginata (Lindberg, 1877 — fig. 1).
«The chairman Professor S. O. Lindberg presented numerous observations concerning the genera Riccia, Preissia, Metzgeria, Radula, etc. Of the genus Riccia the chairman had found during his botanical trip to Ladoga Karelia last summer besides R. natans — earlier known from these areas — also the species R. fluitans, R. minima L. (= sorocarpa Bisch.) and a formerly undescribed species R. marginata Lindberg, which is one of the largest among the Scandinavian species as well as notable through its unusually loose tissue composed of large cells and through the ovally elliptic, blunt, centrally flat lobes with swollen margins. It is closest related to the North American R. Lesquereuxii. The former one of the last-mentioned two species [must mean R. sorocarpa. — T. A.] had occurred at several places in the Kirjavalaks and Puutsalo regions in humus-
Ordforanden professor Lindberg meddelade atskilliga iakttagelser rorande slagtena Riccia, Preissia, Metzgeria, Radula m. fl. Af slagtet Riccia hade ordforanden under en senaste sommar foretagen botanisk resa i Ladoga
Karelen furinit utom den forut fran dessa trakter kanda R. nutans, arterna fluitans, minima L. (= sorocarpa Hisch.), samt en forut obeskrifven art R. marginata Lindberg en af de storsta bland de skandinaviska arterna samt utmarkt genom sin utomordentligt losa, af stora celler bestaende vaf-nad och sina ovalt elliptiska, trubbiga med ansvallda kanter foj-sedda och i midten platta flikar, narmast beslagtad med den nordamerikanska R. Lesquereuxii. Den forra af de tva sistnamnda hade forekommit pa flere stallen i Kirjavalaks och Puutsalo trakterna i mullrika och fuktiga bergsprickor, den senare jmnigt pa tva lokaler i Sordavala trakten. Af
Fig. 1. Original description of Riccia marginata: Meddelanden af Societas pro Fauna et Flora Fennica "1876" 3 Feb - 3 Mar 1877. 1: 105-106. [In Swedish]
rich and moist rock crevices, the latter one [must mean R. marginata. — T. A. ] at two places in the Sordavala tract.»1
This description does not provide enough basis for correct species interpretation according to the present taxonomy. However, it includes morphological characters which Lindberg clearly regarded as diagnostic, such as large size, unusually loose tissue with large cells, and elliptic, blunt, centrally flat lobes with swollen margins. Therefore R. marginata is regarded as undoubtedly validly published.
Typification of Riccia marginata
Syntypes of Riccia marginata were found in H-SOL in folders of R. bifurca Hoffm. (7 specimens) and among Piippo: Hepaticae exsicca-tae S. O. Lindbergii (no. 525) as R. beyrichiana. The former 7 specimens were studied in 1926 by C. E. O. Jensen and annotated as R. lescuriana Austin, which today is considered to be a synonym of R. beyrichiana. The syntype materials are homogeneous and represented by plants with the habit of R. beyrichiana and spores with a sculpturing, similar to that species, but the spores are generally of smaller size.
1 Translated from Swedish by T. Ahti.
Riccia marginata Lindb., Meddelanden af Societas pro Fauna et Flora Fennica "1876" 3 Feb - 3 Mar 1877. 1: 106. (Plates I: 3-9; III: 1-6, 8, 9).
[Morgonbladet 1874 (237): 1. 13 Oct 1874 (nom. nud.); Helsingfors Dagblad 1874(289): 2. 23 Oct. 1874 (nom. nud.); Bot. Not. 1874: 156. 3 Nov. 1874 (nom. nud.)].
Thalli in partial rosettes or in intricate mats or single, glistening, pale or greyish-green, frequently with violet or reddish-purple margins near branch apices, usually becoming yellowish-white to brownish with age. Thalli 1-3 furcate or simple, 2-5 mm long, ultimate branches (0.75)1-1.5(2) mm broad, 1-2 mm long, linear-cuneate to linear-obovate, with a broad flat channel (1/4)1/3-1/2 of branch-width or wider and thick, raised and slightly convex margins, 250-350(500) ^m wide, the apex broadly rounded or somewhat narrowed or retuse; the margins mostly entire, sometimes with a few short, generally thin-walled, blunt and ± smooth hairs, with apical wall not thickened, to 125 ^m long and 30-40 ^m wide (Plate III: 2, 8, 9). Thallus long persistent, in section near apices of ultimate lobes x 1.5-2 as wide as high, in older sectors x 2.5-3.5(4) as wide as high, sides ± oblique and ± swollen to lobe apices. Cells of dorsal thallus surface 45-55 x 45-60 ^m. Ventral scales violet to hyaline. Cells of ventral scales 38-80 ^m long and (25)35-55 ^m wide (hyaline scales usually have larger cells, whereas pigmented scales have shorter cells), with thin to somewhat thickened walls.
?Monoicous, often fertile. The archegonium neck deep violet. Spores deep brown at maturity, yellowish and brownish when immature, rounded triangular in outline, 75-90(115) ^m in diam., with wing-like lighter pigmented and finely papillose, not areolate edge, which gets broader (to 7 ^m) toward the angles. Angles often with pores. Distal spore surface with 5-6(7) alveoles across, each 10-13(15) ^m, some alveoles may be incomplete. Proximal spore surface distinctly finely areo-late-papillose (areoles 5-7 ^m in diam.) when immature to indistinctly areolate and roughly papillose when mature (Plate I: 3, 5, 7, 8). Trilete scar ± distinct.
Ecology. On partly shaded or open, moderately dry, bare brown humus soil over and in crevices of granite rocks near Lake Ladoga in area of high air humidity. Associated with Riccia sorocarpa Bisch. and Asterella gracilis (F. Weber) Underw. [Mannia gracilis (F. Weber) Schill et D. G. Long]. The type locality also has amphibolite in the bedrock.
Lectotype (designated here): Russia. Republic of Karelia. Karelia ladogensis: "occidentem versus Liikolavuori1, ad terram nudam apricam
Liikkolanmaki or Liikkolanvuori at present.
et in fissuris humosis solo apertis, numquam in umbratis montis, 3 verst e Sordavala", 9 Julii 1874. S. O. Lindberg in Piippo: Hepaticae exsiccatae S. O. Lindbergii no. 525, as Riccia beyrichiana Lehm. (H 4230603).
Syntypes. Russia. Republic of Karelia. "Fennia, Ladoga, Sordavala, in monte Liikolavuori", 9 Julii 1874 S. O. Lindberg (H-SOL 2745018); "Karelia ladogensis, Sordavala, in m. Liikolavuori", 1 Julii 1874 S. O. Lindberg (H-SOL 2745020); "Fennia, Ladoga, Sordavala, in fiss. humosis mont. Liikolavuori", 18 Junii 1874 S. O. Lindberg (H-SOL 2745001); "Fennia, Ladoga, Sordavala, una c. R. minima et Fimbriaria ad terram nudam apricam et in fissuris humosis solo apertis, numquam in umbrosis, mont. amphibol. Liikolavuori, occidentem versus non rara", ... 18 Junii 1874 S. O. Lindberg (H-SOL 2745015); "Sordavala, Liikolavuori", 18 Junii 1874 S. O. Lindberg (H 4230602).
Specimens not cited in the protologue: "Fennia, Ladoga, ins. Puut-salo, in terram humosam et humidiusculam praeruptis rup. granit", 30 Junii 1874 S. O. Lindberg (H-SOL 2745 016); Ladoga, ins. Puutsalo, 30 Junii 1874 S. O. Lindberg (H 4230601).
Topotype. Russia. Republic of Karelia. North shore of Lake Ladoga, outskirts of town of Sortavala, western slope of Liikkolanmaki (Liik-kolanvuori) Mt., near highway (61°43'31.1" N, 30°42'06.0" E), open granitic rocky slope surrounded by forest, on exposed bare moderately dry brown soil over granite rock, ass. with Riccia sorocarpa and Asterella gracilis, 19 July 2011 A. D. Potemkin, V. M. Kotkova, A. I. Maksimov № L11-21, L11-22b (LE). A few thalli with immature green and brown spores.
Taxonomic position of Riccia marginata
Riccia marginata shares most characters of R. beyrichiana as treated by recent European authors (Jovet-Ast, 1986; Paton, 1999; Damsholt, 2002). It differs, however, from the latter in a mostly narrower [(0.75)1.0-1.5(2.0) mm vs. 0.8-2.5(3.0) mm)] and shorter thallus (2-5 mm vs. 5-15 mm) and smaller spores [75-90(115) ^m vs. (70)90-120(130) ^m] with fewer distal alveoles [5-6(7) vs. (5)6-9] as well as in a weaker development of marginal hairs or in totally lacking hairs.
Spore structure in the Riccia beyrichiana-marginata complex
Spores of both the treated species are rounded-triangular in outline. Their general structure in R. marginata is essentially similar to what is found in R. beyrichiana. It should be noted that light microscope observations of the spores may result in misinterpretation of the structure and above all in delimitation of the wing. The marginal area of spore
surface (the area between distal and proximal spore surfaces) in these species is usually devoid of areolation, ± papillose and looks lighter than the rest of spore surface (Plate I). Because of that it may be defined as a wing. In fact the wing in these species is mostly not developed and the marginal spore area represents a structure resembling a mountain range between the distal and proximal spore surfaces (Plate I: 10, 11; Macvicar, 1926: 18, Fig. 3). The marginal spore area often bears pores, located at the angles and they are mostly turned to the distal surface of the spore (Plate I: 2-4, 10, 11). The papillose structure of marginal surface in Riccia marginata and most phenotypes of R. beyrichiana differs from R. bifurca. The latter species has spore size similar to R. marginata but has a more extensive areolation of the distal surfaces expanded to the almost smooth wing (Plate II: 1, 3, 7). Occasionally R. beyrichiana may develop spores similar to R. bifurca both in areolation and wing. Such spores have been found in material issued in V. Schiffner: Hepaticae europaeae exsiccatae no. 1141, as R. lescuriana Austin var. glaucescens (Carrington) Müll. Frib. (Plate II: 4-6, 8), and are also illustrated by Jovet-Ast (1986: Pl. 64: 61, 62) and on website "Identification des Ricciaceae d'Europe". Spores of R. lescuriana var. glaucescens differ from spores of R. bifurca in being larger [100-115 pm vs. (65)70-90(100) pm], in having variable areolation of the proximal surface and in distinctness of the trilete scar (cf.: Plate II: 4-6, 8 vs. 1, 3, 7). Spores of R. beyrichiana from the Mediterranean (Jovet-Ast, 1986: Pl. 39: 9, 10; 64: 61, 62; website "Identification des Ricciaceae d'Europe") are even more similar to R. bifurca in areolation of the proximal surfaces. They mostly differ from spores of the latter species in larger size. The Mediterranean specimens of R. beyrichiana have a variable trilete scar, according to Jovet-Ast (1986: 337) strongly or feebly developed — "à marque triradiée forte or faible" (cf. Jovet-Ast, 1986: Pl. 39: 9, 10).
The structure of proximal spore surfaces of Riccia marginata and R. beyrichiana apparently depends on spore maturity and, according to Damsholt (2002: 792), probably on humidity of the habitat. Damsholt (l. c.) mentioned that "plants from Nordic countries, as well as plants from Greenland and North America, have spores with smooth inner face (i. e. proximal surface), but some Nordic plants have spores with shallowly and indistinctly alveolate inner face. These plants originate from the very humid northern part of the Swedish west-coast, perhaps indicating a character linked to humid climatic conditions." It is possible, that the distinct areolation of proximal surfaces of spores, found in Mediterranean populations and illustrated by Jovet-Ast (1986), could be caused by a more humid local climate.
The immature, yellowish brown spores develop distinct fine areolation on proximal surface (Plate I: 5), whereas the mature dark brown spores loose such an areolation apparently due to thickening of the spore wall beneath the areolation and the lamellae of the alveoles (Plate I: 1, 3, 7, 8). Paton (1999: 578) noted: "As spores mature the lamellae forming the wall of the alveolae may become thicker and the tubercules may be more robust and the spores often darken with age". Such correlations between spore maturity and structure of its surface definitely must be taken into account, when spore structure is considered, as well as humidity conditions during spore maturation should be considered.
A comparison of Riccia marginata and R. beyrichiana in thallus characters provides little differences. R. marginata differs from R. beyrichiana in the mostly narrower and shorter thalli and the scarce formation of marginal hairs. The latter species, however, is variable in those characters (Jovet-Ast, 1986; Schuster, 1992; Paton, 1999) and the above-mentioned distinctions cannot be diagnostic. It can be hypothesized that R. marginata may represent an isolated population of R. beyrichiana, formed after the Pleistocene, with origin in spores, distributed in -, and transferred from western Europe.
In 2011, one of the authors, Potemkin, made an attempt to collect R. marginata at the type locality near Sortavala to obtain fresh material for molecular comparison of R. marginata and R. beyrichiana. However, only few and rather weakly developed thalli (Plate III: 3) were found (see topotype cited above).
The facts above persuaded us to recognize Riccia marginata as a phase of R. beyrichiana distinguished by smaller spores and thalli. To which degree it is taxonomically distinct from R. beyrichiana needs to be clarified by molecular studies in the future, when sufficient material is available. Taking into account that R. beyrichiana was described from North America and the American populations are reported to differ from the European ones (Schuster, 1992), material from both continents and from northern and southern localities with different climate and humidity must be considered for such a study.
Acknowledgements
Anatoliy I. Maksimov and Oleg L. Kuznetsov are gratefully acknowledged for organization of a trip to the type locality of Riccia marginata near Sortavala. A. I. Maksimov and Vera M. Kotkova are thanked for assistance in the field. We are grateful to Pekka Isoviita for confirmation of C. E. O. Jensen's handwritings on labels of Riccia marginata. This study would be impossible without technical assistance with SEM study kindly provided by Lyudmila A. Kartseva and loan arrangements of cited materi-
als from Botanical Museum University of Helsinki to St. Petersburg. Kell Damsholt is gratefully acknowledged for reading the manuscript, and providing valuable advice and corrections.
References
Arnell S. Illustrated Moss Flora of Fennoscandia. I. Hepaticae. Lund, 1956. P. 1-308. — Buch H. Suomen Maksasammalet. Otava, 1936. 116 p. — Damsholt K. Illustrated flora ofNordic Liverworts and Hornworts. Lund, 2002. 840 p. — Identification des Ricciaceae d'Europe. URL: http://abiris.snv.jus-sieu.fr/hepatiques/riccia.html#applet — Geissler P., Bischler H. (eds.). Index Hepaticarum. Racemigemma to Zoopsis. Vol. 12. Berlin; Stuttgart, 1990. 337 p. — Index Hepaticarum Names Database. URL: http://www.ville-ge.ch/ musinfo/bd/cjb/hepatic/index.php — Jorgensen E. Norges Levermoser // Bergens Mus. Skrifter. 1934. N 16. P. 1-343. — Jovet-Ast S. Les Riccia de la région Méditerranéenne // Cryptog. Bryol. Lichénol. 1986. Vol. 7., Suppl. Fasc. 3. P. 287-431, pls. 1-65. — Konstantinova N.A., Potemkin A. D., Schlja-ko v R. N. Check-list of the Hepaticae and Anthocerotae of the former USSR // Arctoa. 1992. Vol. 1. P. 87-127. — Konstantinova N. A., Bakalin V. A. et al. Checklist of liverworts (Marchantiophyta) of Russia // Arctoa. 2009. Vol. 18. P. 1-64. — Koponen T., Isoviita P., Lammes T. The bryophytes of Finland: an annotated checklist // Flora Fennica 6. Helsinki-Helsingfors, 1977. 77 p. — Lindberg S. O. Sällskapets pro Fauna & Flora Fennica sammanträde den 3 oktober // Meddelanden af Societas pro Fauna et Flora Fennica "1876" 3 Feb - 3 Mar 1877. Haft. 1. S. 105-107. — Macvicar S. M. The student's handbook of British hepatics. Eastbourne; London, 1926. 464+x p. — Müller K. Die Lebermoose Deutschlands, Oesterreich u. d. Schweiz // Rabenhorst's Krypto-gamen Flora, 2 Aufl. Leipzig, 1905-1916. Bd. 6. S. 1-870. — Müller K. Die Lebermoose Europas // Rabenhorst's Kryptogamen Flora, 3 Aufl. Leipzig, 19511958. Bd. 6. S. 1-1365. — Norrlin J. P. Symbolae ad floram Ladogensi-Kareli-cam // Meddelanden af Societas pro Fauna et Flora Fennica. 1878. Haft. 2. S. 1-33. — Paton J. A. The liverwort flora of the British Isles. Essex, 1999. 626 p. — Potemkin A. D., Sofronova E. V. = Потёмкин А. Д., Софронова Е. В. Печеночники и антоцеротовые России. Т. 1. = Liverworts and hornworts of Russia. Vol. 1. СПб.; Якутск, 2009. 368 с. [in Russian and partly in English] — [Savicz L. I., Ladyzhenskaj a K. I.] Савич Л. И., Ладыженская К. И. Определитель печеночных мхов Севера Европейской части СССР [Handbook of the liverworts of the North of European part of the USSR]. М.; Л., 1936. 309 с. [in Russian] — [Schljakov R. N.] Шляков Р. Н. Печеночные мхи Севера СССР. Вып. 5. Печеночники: Лофоколеевые — Риччиевые. [Liverworts and hornworts of the North of the USSR. Iss. 5. Liverworts: Lophocoleineae - Ricciineae]. Л., 1982. 196 c. [in Russian] — Schuster R. M. The Hepaticae and Anthocerotae of North America east of the hundredth meridian. Chicago, 1992. Vol. 6. xvii + 937 p. — Tropicos Database. URL: http://www.tropicos.org/
Plate I. Spores of Riccia marginata (3-9) and R. beyrichiana (1, 2, 10, 11). 1, 3, 5, 7, 8 — proximal surface (5 — of immature yellowish-brown spore); 2, 6, 9 — distal surface (2 — with pores at angles; 6 — of immature yellowish-brown spore); 4 — distal and lateral aspect with pore; 10 — lateral aspect with pore; 11 — structure of edge between distal and proximal surfaces (fragment of 10, magnified). 1, 2 — from Sweden, Bohuslan H-SOL 2745012; 3 — from H-SOL 274501 (syntype of R. marginata); 4-6, 8, 9 —from H-SOL 4230603 (lectotype of R. marginata); 7 — from H-SOL 2745018 (syntype of R. marginata); 10, 11 — from Belarus, 24.06.1989 D. I. Tretjakov (LE).
Plate II. Spores of Riccia bifurca (1-3, 7) and R. beyrichiana (R. lescuriana
var. glaucescens) (4-6, 8). 1, 4, 7 — proximal surface; 2 — lateral aspect; 3, 5, 6, 8 — distal surface. 1-3, 7 — from Orel Region, Kotkova OP 09-130a, LE; 4-6, 8 — from North Wales, Portmadoc, V. Schiffner: Hepat. Europ. Exs, no. 1141, as R. lescuriana var. glaucescens (LE).
Plate III. Riccia marginata (1-6, 8, 9) and Riccia bifurca (7). 1, 2 — apical part of thalli (2 — with vestigial marginal cilia); 3, 7 — thalli; 4, 5 — spores, light microscope view, proximal and distal surfaces respectively; 6 — thallus cross section; 8, 9 — marginal cilia. 1 — from H-SOL 274501 (Syntype of R. marginata); 2-6, 8, 9 — from topotype of R. marginata Potemkin, Kotkova, Maksi-mov № L11-21 (LE); 7 — from Orel Region, Kotkova OP 09-130a (LE). Scale bars:
1--300 ^m; 2--100 ^m; 3-- 350 ^m; 4, 5--25 ^m; 6--150 ^m; 7 —
~ 500 ^m; 8, 9--10 ^m.
