J. Hattori Bot. Lab. No. 76: 173- 181 (Oct. 1994)

TAXONOMY AND PHYTOGEOGRAPHY OF

IS THE PACIFIC AN AREA OF SPECIATION FOR SOME FOLIOSE GENERA OF THE FAMILY ?

ROLAND MOBERG1

ABSTRACT. Speciation in lichens is poorly known, as the nature of the sexual reproduction is equivocal and there is no support from fossil lichens. Using examples from the Physciaceae, criteria for speciation in lichens are discussed. Some of the genera are well-developed in the Pacific, and for Phaeophyscia the and world distribution is presented and correlated with presumed speciation processes. The Physconia, which is represented by a larger number of species in the northern Pacific than in other parts of the world, is discussed and compared with the presence in other areas. In the southern Pacific the genus is fairly well-developed and evidence for areas of speciation is presented.

INTRODUCTION During my work on the lichen family Physciaceae, I became aware that the number of species of various genera are significally different in different parts of the world. The reason for such differences may be difficult to find but it obviously has some connection with speciation. Speciation within vascular plants is fairly well known and there are a number of comprehensive books on the subject (e.g. Grant 1981). The general idea of speciation accepted for flowering plants may be defined as the rate of gene flow and the intensity of selection. This means that a sexual process has to be involved. In higher plants sexuality is well-known and sexual processes are advanta­ geous when the environment is changing. The selection then acts upon the diversity. Vegetative reproduction on the other hand is advantageous for a species in a ± constant environment. This general statement should also be valid for lichens even though we know very little about their sexual processes and thus about gene flow. Another problem with lichens is our poor knowledge of the age of existing species and we have no idea at all of ancestral, extinct species as no fossil material is known. However, the following presentation is based on the assumption that speciation in lichens follows the same general pattern as in vascular plants; isolation of genotypic variation and selection. Several recent papers deal with various aspects of speciation. Karnefelt ( 1990) put forward the idea that speciation must be slow, as some species appear in both South

1 Botanical Museum, Uppsala University, Villaviigen 6, S- 752 36 Uppsala, Sweden. 174 J. Hattori Bot. Lab. No. 76 I 9 9 4

America and Africa, two continents now separated by plate tectonics. Galloway ( 1988) on the other hand thinks that "it is simplistic to view tectonic plates as Noah's Ark, transporting vicariant remnants of a Mesozoic Gondwana biota". The different parts of Gondwanaland started to rift apart some 80 million years ago. Another aspect which should be taken into consideration is the species-pair concept of Poelt (1970, 1972). Perhaps primary and secondary species concept is a better terminology. A recent summary is to be found in Mattsson and Lumbsch ( 1989). Generally, primary and secondary species are treated at species level but it has been suggested that a secondary species is just a reproductive strategy of a primary species and thus a subspecific taxon (Tehler 1982). In my view, primary and secondary species are closely related species which may have differences other than a different mode of dispersal. However, most probably both types have their beginning in a common ancestor. This will not be discussed further here, but it should be stressed that asexual propagation is common in lichens and that many species have both sexual and asexual modes of propagation.

SPECIATION IN THE PHYSCIACEAE In the Physciaceae it is difficult to relate speciation to plate tectonics or to know which species are secondary species of primary species. In some cases it is fairly evident which species constitute species pairs but in most cases there may be more than two species involved. Bearing the above definition of speciation in mind, we know that only fertile species are involved in the process. In such cases the primary and secondary species should be of interest if we assume that they differ not only in their reproduction strategies. The number of species in the one or the other group may give us some ideas about speciation within a genus. To test this idea the species in the generaPhaeophyscia, Physcia and Physconia were grouped according to different reproduction strategies in various parts of the world (in Table 1- 3 the various species are listed). In Figs. 1- 3 these groupings are presented graphically. In general there are differences in the size of distribution areas between sexual and asexual species. A species with sexual reproduction usually has a more restricted distribution area while a species with asexual reproduction has a much wider area of distribution. Examples of the first category are the fertile Phaeophyscia hirtuosa and Phaeophys­ cia pyrrhophora in E. Asia, Phaeophyscia laciniata in Hawaii, Physcia dilatata in E. Africa, Physcia coronifera in S. America, Physconia grumosa in E. Asia and Physconia servitii in Europe. Examples of the second category are the sorediate species Phaeophyscia chloantha, Phaeophyscia hispidula, Physcia adscendens, Physcia tribacia . Physconia enteroxantha, and Physconia perisidiosa. There are, as usual, exceptions from this general statement as some fertile species have a fairly extensive distribution area e.g. Phaeophyscia ciliata, Phaeophyscia en­ dococcinodes, Physcia aipo/ia, Physcia stellaris, and Physconia distorta. Sorediate species with limited distributions are other exceptions e.g. Phaeophyscia R. MOBERG: Speciation for some foliose genera of Physciacae 175

Table 1. Accepted species of Phaeophyscia with distribution (a = apothecia only, s = soredia, i= isidia, != lobules) . a s i 1 Eur EAs EAf NAm SAm 1. adiastola (Essl.) Essl. s x x 2. chloantha ( Ach.) Moberg s x x x x x 3. ciliata (Hoffm.) Moberg a x x x 4. confusa Moberg a x x 5. constipata (Norrl. & Nyl.) Moberg a x x x 6. denigrata (Hue) (incl. P. nepalensis) a x x 7. endococcina (Korb.) Moberg a x x x (incl. P. decolor and P. erythrocardia) 8. endococcinodes (Poelt) Essl. a x x x x x 9. endophoenicea (Harm.) Moberg s x 10. fumosa Moberg a x 11. hirsuta (Mereschk.) Essl. s x x x x (incl. P. cernohorskyi) 12. hirtella Essl. a x 13. hirtuosa (Krempelh.) Essl. a x 14. hispidula (Ach.) Essl. s x x x x x 15. imbricata (Vain.) Essl. a x x 16. insignis (Mereschk.) Moberg s x x 17. kairamoi (Vain.) Moberg x x x 18. laciniata Essl. Hawaii a 19. leana (Tuck.) Essl. a x 20. melanchra (Hue) Hale s x x 21. nigricans (Flk.) Moberg x x 22 . orbicularis (Neck.) Moberg s x x (incl. P. pusilloides) s 23. poeltii (Frey) Nimis a x 24. primaria (Poelt) Trass a x 25. pyrrhophora (Poelt) Awas. & Joshi a x 26. rubropulchra (Degel.) Essl. s x x 27 . sciastra (Ach.) Moberg s i x x x x 28 . trichophora (Hue) Essl. a x 14 17 7 19 5 endophoenicea, Phaeophyscia insignis, Physcia albo-plumbea and Physcia rolfii. Another aspect to bear in mind is that there is a tendency within genera to have more asexual species towards the Poles, just as we find in higher plants (vivipary). Species with soralia and/or isidia have been regarded as secondary species and all others as primary species. This means that species with lobules and those which might be dispersed by fragmentation are included in the group of primary species. Three groupings have been made: a. Total number of species in the various areas Europe, East Asia, East Africa, North America and South America. 176 J. Hattori Bot. Lab. No. 76 I 9 9 4

Table 2. Accepted species of Physcia with distribution (a = apothecia only, s = soredia, i = isidia, 1= lobules). a s Eur EAs EAf NAm SAm

I. adscendens (Fr.) Oliv. s x x x x x 2. aipolia (Humb .) Ftinrohr a x x x x x 3. alba (Fee) Mtill. Arg. a x x 4. albata (F. Wils.) Hale s x x 5. albinea ((Ach.) Malbr. a x x x 6. albo-plumbea (Tay!.) Nyl. s x 7. americana G. K. Merr. a x 8. atrostriata Moberg s x x x x 9. biziana (A. Massal.) Zahlbr. a x x x x 10. caesia (Hoffm.) Ftirnrohr s x x x x x 11. cinerea Moberg a x 12. clementei (Sm.) Maas Gest. x x 13. convexa Moberg a x x 14. convexella Moberg a x 15. coronifera Moberg a x 16. crispa Nyl. s x x x 17. decorticata Moberg x 18. dilatata Nyl. a x 19. dimidiata (Arnold) Nyl. s x x x x 20. dubia (Hoffm.) Lettau s x x x x x 21. erumpens Moberg s x x x 22. halei Thoms. a x 23. integrata Nyl. a x x x 24. kalbii Moberg a x 25 . krogiae Moberg s x x x 26. lacinulata Miill. Arg. a x x 27. /obulata Moberg a x 28. /opezii Moberg x 29. magnussonii Frey a x 30. manuelii Moberg a x 31. mexicana de Lesd. a x 32. millegrana Degelius a x 33. nubila Moberg s x 34. pachyphylla Miill. Arg. a x 35. phaea (Tuck.) Thoms. a x x x 36. phaeocarpa (Nyl.) Hue a x 37. ponsinsii Hue s x x 38. rolfii Moberg s x 39. scopu/orum (Lamb. & Vezda) Poelt & Nimis a x 40. semipinnata (Gmelin) Moberg a x 41. sinuosa Moberg s x 42. sorediosa (Vain.) Lynge s x x x 43. stellaris (L.) Nyl. a x x x x x 44. subtilis Degelius s i x 45. tenella (Scop.) DC. s x x x 46. tenuis Moberg a x 47. tribacia (Ach.) Nyl. s x x x x x 48. tribacoides Ny!. s x x x 49. undulata Moberg s x x x 50. verrucosa Moberg a x 51. vitii Nadv. s x 20 14 21 21 34 R. MOBERG: Speciation for some foliose genera of Physciacae 177

Table 3. Accepted Physconia species with distribution (a= apotheciaonly, s = soredia, I= lobules). a s Eur EAf EAs NAm SAm

I. detersa (Nyl.) Poelt s x x x 2. distorta (With.) J. Laundon a x x x x 3. enteroxantha (Nyl.) Poelt s x x x 4. grisea (Lam.) Poelt s x x 5. grumosa Kashiw. & Poelt a x 6. hokkaidensis Kashiw. a x 7. kurokawae Kashiw. s x x 8. lobu/ifera Kashiw. a x 9. muscigena (Ach.) Poelt a x x x 10. perisidiosa (Erichs.) Moberg s x x x x 11. servitii (Nadv.) Poelt a x 12. subpulverulenta (Szat.) Poelt a x 13. venusta (Ach.) Poelt a x

tot Eur EAs EAf NAm SAm 28 14 17 7 19 5

~ Eur EAs EAf NAm SAm Fig. I. Dispersal strategies in Phaeophyscia. Left-hand column primary species, right-hand column secondary species. Lower part shows species restricted to various areas. 178 J. Hattori Bot. Lab. No. 76 I 9 9 4

tot Eur EAs EAf NAm SAm 51 20 14 21 21 34

Eur EAs EAf NAm SAm Fig. 2. Dispersal strategies in Physcia . Left-hand column primary species, right­ hand column secondary species. Lower part shows species restricted to various areas.

b. Proportion of primary species in the various areas. c. Proportion of primary species restricted to the various areas in relation to the total number of primary species. These groups are judged to be of interest as regards areas of speciation of a genus and a high proportion is thought to indicate strong evidence for an evolutionary centre. R. M OBERG: Speciation fo r some fo liose genera of Physc iacae 179

tot Eur EAs EAf NAm SAm 13 8 8 3 6 1

Eur EA s EAf NAm SAm Fig. 3. Dispersal strategies in Physconia . Left-hand column primary species, right-hand column secondary species. Lower part shows species restricted to various areas.

RESULTS Phaeophyscia Of the 28 species listed (Table 1) 16 (61 % ) are primary species (P) and 12 (39% ) secondary species (S). In Europe these proportions are: P = 5 (36% ) and S= 9 (64% ); in East Asia: P = l l (65 % ) and S= 6 (35% ); in East Africa: P = 3 (43 % ) and S= 4 (57% ); in North America: P = 8 (42% )and S= 11 (58% ); in South America: P = 1 (20% ) and S= 4 (80%). Fig. 1. For species restricted to Europe only, the proportions are: P = 1 ( 50% ) and S = 1 (50%); species restricted to East Asia: P = 4 (100%) and S= O; species restricted to East Africa: P = 1 (100%) and S= O; species restricted to North America; P = 2 (100% ) and S= O; no species are restricted to South America. Fig. 1. Physcia Of the 51 species listed (Table 2) 27 (53 % ) are primary species (P) and 24 (47% ) secondary species (S). In Europe these proportions are: P = 8 (40% ) and S= 12 (60% ); in East Asia: P = 5 (36% ) and S= 9 (64% ); in East Africa: P = 6 (29%) and S= 15 (71 % ); in North America: P = 12 (57% ) and S= 9 (43% ); in South America: P = 16 (47% ) and S= 18 (53% ). Fig. 2. For species restricted to Europe only, the proportions are: P=3 (75 % ) and S= 1 (25 % ); no species are restricted to East Asia only; species restricted to East Africa: P = 2 (67% ) and S= 1 (33% ); species restricted to North America: P = 4 (80% ) and 180 J. Hattori Bot. Lab. No. 76 I 9 9 4

S= 1 (20%); species restricted to South America: P = 9 (64%) and S= 5 (36%). Fig. 2. Physconia Of the 13 species listed (Table 3) 8 (62%) are primary species (P) and 5 (38%) secondary species (S). In Europe these proportions are: P = 5 (63%) and S= 3 (37%); in East Asia: P = 4 (50%) and S= 4 (50%); in East Africa: P = 2 (67%) and S= 1 (33%); in North America: P = 2 (33%) and S= 4 (67%); in South America: P = O and S= 1 (100%). Fig. 3. For species restricted to Europe only the proportions are: P = 3 ( 100%) and S = O; species restricted to East Asia: P = 3 ( 100%) and S = 0. No species are restricted to East Africa or to North America or to South America. Fig. 3.

It is obvious from Figs. 1-3 that there are differences between the genera treated in the various areas. In Europe Phaeophyscia has 14 (50%) species, Physcia 18 (35%) species, and Physconia 8 (62%) species. In East Asia Phaeophyscia is represented by 17 (61%) species, Physcia 14 (27%) species, and Physconia 8 (62%) species. In East Africa Phaeophyscia comprises of 7 (25%) species, Physcia 21 ( 41 %) species, and Physconia 3 (23 % ) species. For North America the numbers are: Phaeophyscia 19 (68%) species, Physcia 21 (41%) species, and Physconia 6 (46%) species. In South America Phaeophyscia has 5 (18%) species, Physcia 34 (66%) species, and Physconia 1 (8%) species.

DISCUSSION Phaeophyscia has the highest number of species in North America (68%), Physcia in South America (66%), and Physconia in Europe (62%) and East Asia (62%). In Table 4 this is marked (a). The next grouping (b) represents the dispersal strategies where we assume that primary species better reflect evolution than secondary species. The highest numbers of primary species for this grouping is for Phaeophyscia in East Asia (65%), for Physcia in South America (57%), and for Physconia in East Asia (67%). In Table 4 this is

Table 4. Genera with the highest number of representatives (marked with a, b or c) in various areas as regards the total number of species, number of primary species, and species restricted to the different areas. Eur EAs EAf NAm SAm Phaeophyscia be a Physcia abc Physconia ac abc R. MOBERG: Speciation for some foliose genera of Physciacae 181 marked (b). Finally, considering grouping c, the primary species restricted to the different areas compared with the total number of primary species show the highest ratio for Phaeophyscia in East Asia (25%), for Physcia in South America (33%), and for Physconia in Europe (38%) and East Asia (38%). In Table 4 this is marked (c). Counting the numbers of markings in Table 4 we find that Phaeophyscia has two hits in East Asia, one in North America, and none in the other areas; Physcia has three hits in South America and none in the other areas; Physconia has three hits in East Asia and two in Europe. This means that Phaeophyscia has more primary species in East Asia than elswhere and of the species restricted to various areas, the highest proportion of primary species is in East Asia. Evidently Phaeophyscia has its main area of speciation in East Asia. In the same Table, the genus Physcia has three hits in South America and consequently this area is the main area of speciation for Physcia, and the genus Physconia has three hits in East Asia and two in Europe which suggests that its main area of speciation is East Asia. Of course these conclusions are founded on assump­ tions, but at least it gives some idea of possible evolutionary tendencies in the genera concerned. Some areas still have to be more thoroughly examined, e.g., Australia and South Africa, but preliminary examinations indicate that the pattern presented will not differ greatly.

ACKNOWLEDGEMENTS I am very greatful to Dr. David Galloway for valuable comments on the manu­ script and for revision of the English text.

R EFERENCES Galloway, D. J. 1988. Plate tectonics and the distribution of cool temperate Southern Hemi­ sphere macrolichens. Bot. J. Linn. Soc. 96: 45- 55. Grant, V. 1981. Plant speciation, 2nd ed. New York. Karnefelt, I. 1990. Evidence of a slow evolutionary change in the speciation of lichens. Bibliotheca Lich. 38: 291- 306. Mattsson, J.-E. & H. T. Lumbsch. 1989. The use of the species pair concept in lichen taxonomy. Taxon 38: 238- 241. Poelt, J. 1970. Das Konzept der Artenpaare bei den Flechten. Dtsch. Bot. Ges. Neue Falge 4: 187- 198. Poelt, J. 1972. Die taxonomische Behandlung von Artenpaaren bei den Flechten. Bot. Notiser 125: 77- 81. Tehler, A. 1982. The species pair concept in lichenology. Taxon 31: 708- 714.