Ph.D. thesis presented to the University of Lordon January, 1966. 3. A. revision of the lichen genus Liman* in Europe and its taxonomic, affinities J. qr. Sheard, V.So., D.I.C., Department of Botany, Imperial College, London 501.7. 2 t Abstract A partial revision of the genus Rinodina in Europe has been undertaken. 96 species have been studied and 41 of these have been reduced to synonomy. The remaining 50 species include speolespalasdtimp) new to science and 2 new combinations. This revision has been carried out with the aid of more refined sectioning and optical equipment than was available to previous workers and with a greater knowledge of the effects of environ- mental modification. The author has also attempted, to apply modern taxonomic principles during the studies and recent dis- coveries regarding the onotgeny and range of form of the apotheeha have also helped in defining the limits of related genera. The subdivision of the genus has been redefined using the spore structure, rather than the spore septation and tballus morphology, as the principle criterion. The relational*p of the genus Rinodim with the other genera of the Bue=awe, end rivaciacea, has also been examined. It has tentatively been suggested that two genera be redesaribed; the genus k4ismajaQi5 to accommodate certain species previously, placed in BuoUi or Rim Klima, end the monospeoifio genus Dita,010141 previously placed under %Lelia, to be transferred to the Plysataoeao. 3. introduotion 5 The problem 5 Historical review 6 Review of lichen taxonomy with particular reference to the genus Ameba 6 Classification' within the Suellitaceae and aainaidatfa 9 Basis of revision and limits of work 15 Materials and methods 16 Herbaria consulted 16 Sectioning and preparation of material for detailed examination ' 17 Reagents and mounting fluids used 18 Apparatus used. 19 Revision of the genus angana 19 Presentation of the species 19 Artificial key to the British species of the genus Nadi1151 21 The genus Natant 21 Sect. Oroular.4. Species i 26 Sect. Evrinodina. Species 2 - 33 29 Seat. itischoblasti4. Species 34. 108 Scot. PlacesthPllto. Species 48 51 145 4. Discussion 156 Modern concepts of lichen taxonomy 156 The dual nature of lichens and their nomenolature 156 Classification of lichens 158 Taxonomic status of 'chemical species' 160 The species concept 162 Subapecific taxa 167 The ontogeny midrange of apothecial structure within the licheoised fungi 169 Nomenclature of apotheoial tissues 169 The ontogeny of the lichen apotheoium 171 Range of apotheolal structure 172 Morphology and anatomy of the species 178 Thallus morphology 178 Apotheoia - morphology 187 Apotheoia - anatomy 192 Taxonomy of the genus Rinodixia 227 The species and taxa of lower rank 227 Subdivision of the genus 235 Relationships with other genera 242 Phylogeny within the Buelliaosas andayiamit 248 Summary 253 Acknowledgements 255 Bibliography 256 5. Introduiotion The Problesi Until the present decade liohenologists have largely limited their studies to the publication of floristio works and have almost totally neglected the monographic treatment of genera. Davis and Heywood (1963) have pointed out that, in respect of the Angiosperms, this is most unfortunate for two reasons: firstly because floras could be written much better if more monographs were available and secondly because systematics cannot advance without monographio research. The same undoubtedly holds true for the lichens and any other group of plants. Following the treatment of the genus Buellia in the British Isles (Mesa, 1960 the author became interested in the delimitation of the two genera Buellia and Rinodina. In the absence of any monographic treatment of all the species of Apladina it was thought desirable that such a work should be commenced in the hope that it would do something to elucidate the problem. This thesis gives the results of the first two years work on the monograph and establishes the blueprint for the remainder of the studies. 6. Historical Review Review of lichen taxonomy with particular reference to the genus Rinodina. The first species belonging to the genus Masa were described after the introduction of the binary system of nomenclature (Linnaeus, 1753) by Aoharius (1798). Two species were described, Lichen sonhodes andis gas. Aoharius was the first worker to devote his attention entirely to lichens and shortly after this time he introduced a system for the classification of the group (Acharius, 1803). In this arrangement greatest importance was given to the form of the thallus but the structure of the apothecium was also taken into account. The species of the genus were placed under,Parmelia Sect. Lecaneria in which the tballus was orustose and the apotheoia partly formed from the thallus. In a later publication (Acharius, 1810) this section was renamed Lecanora subgenus Rinodina and two more species, Lecanora colobina and L. milivina were added to the list, although numerous other subspecies'and varieties were also described that are now regarded as separate species. Gray (1821) was the first worker to use Rinodina as a generic name but it was still used in the same sense as Acharius' Sect. Lecanaria, to include the modern genera Lecanora and Caloolaca amongst others. 7. The great works of Plerke (1815-19), Pries(1831) and Sohaerer (1850) all followed the classification of Acharius although their species conception varied considerably. The use, by De Notaris (1846), of spore characters in classification constituted a great advance in liehenology. Such a system had previously been suggested by Fee (1824) but never utilised. The value of this system of classification was quickly realised and the works of Massalongo (1852), Koerber (1855) and Mudd (1861) all employed spore characters in defining genera, while morphological characters were retained for the classification of Families. Thus, in Veda (loc. cit.) the genus,Rinodin, is found with Calloeismq (palotlaca), /meanie, Lecanor and Itaggdosa in the Tribe (Family) jeoanoraceeel the genera being separated primari4 by spore characters. Not all authors were of the same opinion however, and !Wander (1854) rejected the use of ascospore Characters except where they were of use in species diagnosis. The occurrence of green cells in lichen 0414 had been known for a considerable time and had, been intensively studied by iallroth (1825) and. Koerber (1839), but it remained for Schwendener (1867) to announce the composite nature of the lichen plant. The association of fungi and algae within lichens came to be regarded as a high/7 developed form of symbiosis and the taxonomic views of most liohenologists of the El • time maybe summed up in the words of Smith (19211):- "AA, system of classification that claims to be a natural one, must, while following as far as possible the line of plant development, take into account the double origin of lichens both from algae and fungi, the essential unity of the class however being proved by the recurring aLalarity between the thalline types of the different *viler. This was the basis for the classification of lichens constructed by Reinke (189496) and elaborated by Zahlbruckner (1926). Although it is now regarded as having severe limitations it is still used in the majority of taxonomio works. In this system the Ascolichena are divided into Series and Subseries based on apothecial structure and morphology. The Families are variously defined, by thallus morphology, algal cells and apotheium structure. The genus Rinodina is thus found in:- Subclass Asooliohens Series Gynmooarpeae Subseries Cyolocarpineae Family Buelliaceae The Family PhYsoiaceae is distinguished from the Buspiacete by its foliose thallus. The genera Buellia and Rinodina constitute the Buelliaceae and are distinguished by their lecideine and lecanorine apothecia respectively. The Physolaceae inoludes the genus PVxine separated from,Phvsoia and Anaotychla in a similar manner by the absence of a thalline margin. The latter 9. two genera differ in the structure of the thallus. A later olassification byliratoon(1928) oombined these two Families as the Phrscipiocae and included the genus Rhizocayson, placed by Zahlbruokner in the Livitmeeae. In many ways this arrangement is a retrograde step and has been shown to be erroneous, at least in part, by Lamb (1940) ana,Sheard (1961.). Unfortunately it is the basis of the current classification of British lichens (Watson, 1953), Classification within the Buelliacese and Physciaoeae. The classification of the Buelliaceae by Zahlbruckner (1926) may be summarised as follows:- Buellia De Notrs. Sect. I Rubue11414 Sect. II Diralotomma Th. Fr. Sect. III D of Stzbgr. Rinodina S. Gray Sect. I Oroularia Malme Soot. I/ Etrinodinft Stzbgr. Sub3oct. Paanvenoria Malmo Conradia Malmo II/ Nischoblastia Mame IV ilacothallia Buelliq Sect. DiuloiciA and MOIL& Sect. Placothallia are distinguished from the other sections of their genera by their squamulose thallus forms. 4310.14 Sect. Diulotomma is distinguished from Sect. Rubuellia by its pseudomuriform or 3-septate spores and spurious thallino margin. Speoles with 3-septate spores are however, found 10. in Sect. Eubuellia but those lack a spurious margin to the apothecia. There are indications (Sheard, 196?.) that soot. AuMaki should be divided into subsections based on spore characters and insertion of the apothecia on the thallue. Thus the Btteilia ditectiformis group of species have pointedly ellipsoid spores differing in structure from the bluntly ellipsoid spores of the At jgadat§ and groups of species. The B. aethelea, group differs from the other groups in having innate apotheota and areolate thalli. The position of those species in the genus with polarilooular spores (Imshaugh: 1955, and Malmo, 1927) has not yet been considered from the tatenamio point of view. Classification within the genus Molina is equally complex and owes much to the -.7ork of Name (1902). The genus is again sub- divided by the use of spore characters. sect..W.4=Q contains those species in which thickening of the spore Ilan is limited to the septum (placodionorph), 38ot.