How to Evaluate Taxa with Poorly Known Taxonomy
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Portugaliae Acta Biol. 20: 25-36. Lisboa, 2002 HOW TO EVALUATE TAXA WITH POORLY KNOWN TAXONOMY Jiří Váňa Department of Botany, Charles University, Benátská 2, CZ-128 01 Praha 2, Czech Republic. [email protected] Váňa, J. (2002). How to evaluate taxa with poorly known taxonomy. Portugaliae Acta Biol. 20: 25-36. Problems with evaluation of the taxa with poorly known taxonomy are discussed. The problems are presented on 13 taxa of liverworts and one of hornworts. As the results, there are three possibilities how the poorly known taxa should be evaluated: not to include in the Red Lists, include as DD (Data Deficient) or formerly as K (Insufficiently Known) or place the taxa in the normal Red List categories (CR, EN, VU). The last option is preferred. Key words: Bryophytes, Red list criteria, taxonomy. Váňa, J. (2002). Avaliação do estatuto de ameaça de taxa poucos conhecidos. Portugaliae Acta Biol. 20: 25-36. Neste trabalho são discutidos os problemas que surgem com a avaliação das ameaças de taxa pouco conhecidos sob o ponto de vista taxonómico. São referidas as dificuldades existentes com 13 taxa de hepáticas e de uma anthocerota. Como resultado são apresentadas três possibilidades de avaliação deste tipo de espécies para serem incluídas nas Listas Vermelhas: DD (Data Deficiente) para as anteriores K (Insuficientemente Conhecidas) ou integração nas novas categorias das Listas Vermelhas (CR, EN, VU). A integração nestas últimas categorias é sempre preferível. Palavras chave: Briófitos, Listas Vermelhas, taxonomia, estatuto de ameaça. INTRODUCTION There are many taxa in all taxonomic groups, which are poorly understood and need clarification. Naturally the same is true for bryophytes. Some taxa with poorly known taxonomy may be classified as threatened, along with well- understood taxa that are threatened. Based on this fact, they can be and sometimes are included in Red Lists or Red Data Books. As an example, in the 26 JIŘÍ VÁŇA Red Data Book of European Bryophytes (ECCB 1995) 50 bryophyte taxa (11 liverworts and 39 mosses) presenting taxonomic problems are mentioned. This number is naturally only approximate; the number of critical taxa changes and may increase or decrease with increasing knowledge and critical study of some groups. The question – how these taxa can be evaluated – is not easy. Many authors of Red Lists or Red Data Books (including also our committee) simply left these taxa out of consideration. Let me analyse the mentioned problem on some examples from the field of hepaticology, which is more familiar to me than muscology. Naturally many of the critical taxa are not threatened and should not be considered in our sense. But some of them are; I selected 13 species (or species pairs) that demonstrate the problems with those taxa where the taxonomic position is unclear. I give some suggestions, which can be discussed. Frullania cesatiana De Not. Included in the Red Lists of Bulgaria (R), Italy (R), Spain (K) and Switzerland (R), reported also from Austria, France and Slovenia. MÜLLER (1951-1958) treated F. cesatiana (type from Italy) as a synonym of F. riparia (type from North America). BISANG et al. (1989) reinstated F. cesatiana for the European populations named as F. riparia and united this species with the closely related east Asiatic, very polymorphic species F. muscicola, reported four years ago also for Macaronesia by SÉRGIO (1985). F. muscicola was maintained at the variety rank (as F. cesatiana var. muscicola). SCHUSTER (1992a) treated F. cesatiana as a taxonomic synonym of F. riparia like as MÜLLER. He kept F. muscicola as a separate species and gave the differences separating both taxa. SIM-SIM et al. (1999) presented some small differences between European populations (F. cesatiana) and North American populations (F. riparia) of this species. They suggested using modern biochemical techniques for solving the problem of whether one or two species are exist. SIM-SIM et al. (1995) described Macaronesian populations as the new species F. azorica. Grolle (GROLLE & LONG 2000) studied abundant material including the types of F. riparia and F. cesatiana. He is convinced that F. riparia and F. cesatiana are conspecific as treated by Müller and Schuster. F. muscicola he treated as a separate species. Suggestion: F. riparia is a complex of related taxa variously treated as species, varieties or synonyms. The taxonomic status of European populations of F. riparia (reported also under F. cesatiana or F. muscicola) and maybe also the relation to Asiatic F. muscicola should be tested by biosystematic (molecular) methods. However, and not dependent on the results of taxonomic studies, F. riparia should be included in the Red Lists or left in the present Red Lists because of its threatened status in Europe. This species is probably very rare in HOW TO EVALUATE TAXA WITH POORLY KNOWN TAXONOMY 27 all countries (incl. also Austria, France and Slovenia). It is known only from relatively small areas in the Pyrenees, Alps and Bulgarian mountains. Frullania illyrica Grolle Described by Grolle (MEYER & GROLLE 1963) from Albania; reported also from Slovenia. Reduced to subspecific level under F. inflata by Schuster (SCHUSTER 1983), later to varietal rank (SCHUSTER 1992a). This species was described on the basis of its few, large oil-bodies in the leaf cells. Recently the Austrian bryologist H. Köckinger (in litt.) studied oil-bodies in Austrian plants of F. inflata. He found they usually have 4-8 small oil-bodies per leaf cell (as usual), but sometimes only 2-3 large ones. The same situation is known from Japan; in some populations only a few, large oil-bodies were found (F. inflata var. magnicorpa Yamada). Therefore, F. illyrica can hardly be maintained and is treated now as a synonym of F. inflata (GROLLE & LONG 2000). Suggestion: This species was, fortunately, not included in national Red Lists (there are no Red Lists in Albania and only one of liverworts in Slovenia). Treated as rare in the European Red List (ECCB 1985), it should be deleted (and the data included in F. inflata). Marsupella spiniloba R. M. Schust. et Damsh. Only in the Red List of Norway (DD); reported also from Iceland and Sweden. Described recently by SCHUSTER & DAMSHOLT (1987), as a species closely related to M. sprucei, from Greenland and discussed in detail by SCHUSTER (1988). Because of the high polymorphism of M. sprucei (incl. also M. neglecta, which is probably an intermediate form transitional to this species, although the Scandinavian reports belong mostly to M. spiniloba; the central European and also northern North American has not yet been checked) it seems to be not completely clear if a good species or only an Arctic modification is at hand. Also SCHUSTER (l.c.) concluded in his discussion “I have no final opinion as to whether or not the last (= M. spiniloba) is a species distinct from M. sprucei.” This problem should be solved soon in connection with my prepared monograph of the genus Marsupella. Suggestion: At this time we do not have exact data about the taxonomic value of this very rare species. Also the reports are very scattered, so perhaps the distribution is incompletely or imperfectly known (to date known in Europe only from Scandinavia, although it may be present in the central European mountains). For the moment there is no exact data about either the species or it’s the threatened status– thus DD. Marsupella stableri Spruce Known only from Britain (not from Ireland), where it is more common than the closely related M. boeckii, and outside Europe only from British Colombia. 28 JIŘÍ VÁŇA Kept as a separate species f.e. by MÜLLER (1951-1958). SCHUSTER (1974) at first treated this taxon only as a variety of M. boeckii. His statement is based on the occurrence of transitional forms between M. boeckii and M. stableri in Greenland (cf. SCHUSTER & DAMSHOLT 1974, SCHUSTER 1988). SMITH (1990) accepted the opinion of SCHUSTER (l.c.). Recently PATON (1999) and GROLLE & LONG (2000) again kept both taxa as separate species. This taxonomic problem should be also solved soon in connection with my prepared monograph of the genus Marsupella. Suggestion: This taxon is not included in the Red List of Britain; its taxonomic status should be clarified. The suggestion for the present time is not to include it in Red Lists (not threatened, and taxonomically not a fully clarified species). Metzgeria simplex Lorb. ex Müll. Frib. Species included in the Red Lists of Bulgaria (R), Czech Republic (Ex), Germany (DD) and Hungary (R). Reported also from France, Italy and Poland. This poorly known taxon closely related to M. conjugata was probably firstly described as M. conjugata var. minor (SCHIFFNER 1893). Independently, KAVINA (1915) described it as M. furcata subsp. hamatiformis; this author also treated M. conjugata as a subspecies of M. furcata. It was newly described as a species by MÜLLER (1941) on the basis of Lorbeer’s studies. Lorbeer separated this species, as he did some other species (of different value), on the basis of different (in this case haploid) chromosome number (n = 9) from the diploid M. conjugata (n = 18); additional differences were found mainly in the cell size. HATTORI (1955), on the basis of the fact that Japanese populations of M. conjugata are haploid (n = 9) in contrast to European ones, named the Japanese populations as M. conjugata var. japonica. The mentioned variety was elevated later to subspecific rank (KUWAHARA 1958) and finally to specific rank (KUWAHARA 1978). On the basis of the above-mentioned facts GROLLE (1983) concluded that M. japonica and M. simplex might be conspecific (this conclusion was not checked). The earliest name of this taxon (if Grolle’s conclusion is correct) should be, however, M. lindbergii (described by SCHIFFNER 1898), as shown by PIIPPO (1991).