Ann. Bot. Fennici 39: 273–299 ISSN 0003-3847 Helsinki 11 December 2002 © Finnish Zoological and Botanical Publishing Board 2002 Morphology, anatomy, and ontogeny in the Asterothyriaceae (Ascomycota: Ostropales), a misunderstood group of lichenized fungi Aino Henssen1 & Robert Lücking2 1) Fachbereich Biologie/Botanik, Philipps-Universität, D-35032 Marburg, Germany 2) Department of Botany, The Field Museum, 1400 South Lake Shore Drive, Chicago, IL 60605-2496, U.S.A. Received 21 February 2001, accepted 17 January 2002 Henssen, A. & Lücking, R. 2002: Morphology, anatomy, and ontogeny in the Asterothyriaceae (Ascomycota: Ostropales), a misunderstood group of lichenized fungi. — Ann. Bot. Fennici 39: 273–299. Based on morphological, anatomical, and ontogenetical data, the systematics of Aster- othyrium, Psorotheciopsis, and Gyalidea (including Solorinella) is revised. The three genera form a natural group for which the name Asterothyriaceae is retained; they share hemiangiocarpous apothecia, true paraphyses, non-amyloid, “annelascaceous” asci, euseptate ascospores, and a chlorococcoid phycobiont. Apothecial ontogeny is characterized by the formation of a covering layer which ruptures during develop- ment. Apothecia are sessile (most species of Gyalidea, Psorotheciopsis) or immersed- erumpent with overarching or recurved teeth formed by the covering layer (some spe- cies of Gyalidea, Asterothyrium). Flask-shaped, immersed pycnidia (type I) occur in all three genera. Squad-conical pycnidia adnate to the margin of the thallus (type II) were found in Psorotheciopsis and Asterothyrium, while applanate pycnidia immersed in the thallus centre (type III) are restricted to Asterothyrium. All pycnidial types produce conidia of variable size, shape and septation. Several characters shared by Psorothe- ciopsis and Asterothyrium, i.e. corticate, whitish thalli, pigmented and/or immersed- erumpent apothecia, large and thick-walled ascospores, and frequent formation of pyc- nidia, are possibly adaptations to their preferred habitat: canopy leaves in the tropical rain forests. The closest relative of the Asterothyriaceae is Gyalideopsis in the Gom- phillaceae. It agrees in most aspects with Gyalidea, but differs by its anastomosing paraphysoids and hyphophorous conidiomata. Both families are placed in Ostropales, sharing hemiangiocarpous apothecia, non-amyloid asci, and “annelascaceous” ascus type, with the Stictidaceae, Odontotremataceae, Thelotremataceae, and Graphidaceae. Key words: Asterothyrium, Gomphillaceae, Gyalidea, Gyalideopsis, lichen, Psorothe- ciopsis, Solorinella, taxonomy 274 Henssen & Lücking • ANN. BOT. FENNICI Vol. 39 Introduction genera of lichenized and non-lichenized fungi (Table 1). Psorotheciopsis itself was assigned to In his monograph of foliicolous lichens, Santes- families such as the operculate Pezizazeae and son (1952: p. 331) wrote about Psorotheciopsis Megalosporaceae in the Lecanorales (Table 2). Rehm: “The lichens of this genus have been A similar situation is found in Asterothyrium stumbling-blocks for mycologists.” Indeed, the Müll. Arg.: the ten species listed in Santesson three species recognized by him do have three (including A. rotuliforme (Müll. Arg.) Sérus. generic synonyms and were referred to ten further and A. umbilicatum (Müll. Arg.) Müll. Arg.; see Sérusiaux & de Sloover 1986, Lücking et al. 1998) have seven generic synonyms (two of Table 1. Generic synonyms of Asterothyrium and Pso- them invalid) and were partly referred to further rotheciopsis, and genera to which species of Asterothy- 12 genera of lichenized and non-lichenized fungi rium and Psorotheciopsis were referred to by different (Table 1). Asterothyrium itself was included in authors (based on Santesson 1952, Lücking et al. 1998, 1999). the Patellariaceae and Thelotremataceae, among other families (Table 2). Asterothyrium (10 species): The Asterothyriaceae are based on Vainioʼs Generic synonyms: (1896) and Zahlbrucknerʼs (1905) Ectolechi- Asterothyrium Müll. Arg. aceae, which included Asterothyrium, Tricharia Psorotheciella Sacc. & Syd. Stictoclypeolum Rehm Fée, Echinoplaca Fée, Actinoplaca Müll. Arg., Lopadiopsis Zahlbr. Diplopeltopsis P. Henn. ex von Höhnel Actinoteichus Cavalc. & Poroca Table 2. Families to which the generic names Aster- Tegoa Bat. nom. inval. othyrium, Psorotheciopsis, Linhartia (= Psorotheciop- Stictopela Bat. nom. inval. sis), Solorinella, and Gyalidea, were referred by differ- Other genera to which species were referred: ent authors, before their rearrangement in Asterothyr- Asterina Lév. iaceae (Lücking 1999). Diplopeltis P. Henn. nom. inval. (non Diplopeltis Endl.) Myxodictyon A. Massal. Asterothyrium Linhartia Sacc. & Syd. Patellariaceae (Müll. Arg. 1890) Psorotheciopsis Rehm Ectolechiaceae (Zahlbruckner 1905) Gyalectidium Müll. Arg. Asterothyriaceae (Watson 1929) Platygrapha Berk. & Broome Asterothyriaceae s.lato (Santesson 1952) Rotula (Müll. Arg.) Müll. Arg. Asterothyriaceae s.stricto (Vezda & Poelt 1987) Mazosia A. Massal. Thelotremataceae (Aptroot in Aptroot et al. 1994) Microphiale (Stiz.) Zahlbr. Psorotheciopsis Ectolechia Trevis. Mollisiaceae (Rehm 1900) Sporopodium Mont. Pezizazeae (Saccardo 1902) Asterothyriaceae s.lato (Santesson 1952) Psorotheciopsis (3 species): Megalosporaceae (Vezda 1973) Generic synonyms: Asterothyriaceae s.stricto (Lücking 1992) Psorotheciopsis Rehm Gomphillaceae (Eriksson & Hawksworth 1987) Linhartia Sacc. & Syd. Linhartia Monospermella Speg. Mollisiaceae (Saccardo 1902) Conicosolen F. Schill. Asterothyriaceae s.lato (Santesson 1952) Other genera to which species were referred: Asterothyriaceae s.stricto (Vezda & Poelt 1987) Calloria Fr. Solorinellaceae (Vezda & Poelt 1990) Trichobelonium (Sacc.) Rehm Solorinella Johansonia Sacc. Peltigeraceae Dumort Tapesia (Pers.) Fuckel Gyalectaceae (Vezda & Poelt 1969) Actinoscypha P. Karst. Asterothyriaceae (Vezda 1979) Megalospora Meyen Solorinellaceae (Vezda & Poelt 1990) Microphiale (Stiz.) Zahlbr. Gyalidea Patellaria Fr. Asterothyriaceae s.lato (Vezda 1966) Catillaria A. Massal. Asterothyriaceae s.stricto (Vezda & Poelt 1987) Bacidia DeNot. Solorinellaceae (Vezda & Poelt 1990) ANN. BOT. FENNICI Vol. 39 • Ontogeny of Asterothyriaceae 275 Sporopodium Mont., and Byssolecania Vain., by Dennetière and Péroni (1998), analyzing 15 among others. When fi rst introducing the name characters in 15 taxa. Psorotheciopsis premnella Asterothyriaceae, Watson (1929) retained Aster- fell in a clade with Linhartia, while Asterothy- othyrium, Byssolecania, and Actinoplaca, still rium merged with Graphidaceae and Thelotrem- a highly heterogeneous assemblage. Santesson ataceae. However, performing a more detailed (1952) recognized six genera as being related: analysis of 31 characters in 24 taxa, Lücking Asterothyrium, Psorotheciopsis, Calenia Müll. Arg., (1999) found that Asterothyriaceae sensu Eriks- Gyalectidium Müll. Arg., Echinoplaca (including son and Hawksworth (1987) and Gomphillaceae Actinoplaca), and Tricharia. This group largely sensu Vezda and Poelt (1987) form coher- corresponds to Ectolechiaceae sensu Vainio and ent groups related to Thelotremataceae and Zahlbruckner, but since the type genus, Sporo- Graphidaceae in the Ostropales. He therefore podium, had to be referred to the Lecanorales, reinstated Asterothyriaceae sensu Eriksson and Santesson adopted the name Asterothyriaceae. Hawksworth (1987), placing Solorinellaceae in Vezda (1979) presented the fi rst modern synonymy. Based on another analysis, using 125 treatment of the family, adding Gyalidea Lett. phenotype characters in 24 species, and follow- (Vezda 1966, Lumbsch et al. 1991), Solorinella ing earlier observations made by Aptroot and Anzi (Poelt & Vezda 1969), Gyalideopsis Vezda Sipman (1991), Aptroot and Lücking (2002) (Vezda 1972, Lumbsch & Hawksworth 1987), merged Solorinella with Gyalidea, leaving the Gomphillus Nyl., and Aulaxina Fée. Linhar- Asterothyriaceae with three genera. tia was segregated from Psorotheciopsis, and In this paper, we present data on the apoth- the latter, on account of its large, thick-walled ecial morphology, anatomy and ontogeny of ascospores, was referred to the Megalosporaceae Gyalidea (including Solorinella), Psorotheciop- (Vezda 1973) and, more recently, to the Gomphil- sis, and Asterothyrium, in order to test our view laceae (Eriksson & Hawksworth 1987, 1993). of this group as a natural entity and to study the Vezda (1979) recognized two entities within the relationships between the different genera and Asterothyriaceae: one with branched and anasto- species. mosing paraphysoids and hyphophorous conidi- omata (Vezda 1973), and a one with unbranched paraphyses and pycnidial conidiomata, including Material and methods Asterothyrium, Gyalidea, Linhartia, and Solo- rinella. After segregating the taxa producing The following taxa were used for morphological, hyphophores in a separate family Gomphillaceae anatomical, and ontogenetic studies: (Vezda & Poelt 1987), the remaining four genera were retained as Asterothyriaceae s.stricto Asterothyrium anomalum Kalb & Vezda var. anomalum: (Eriksson & Hawksworth (1987). Brazil, Kalb s.n. (hb. Vezda, isotype). Argentina, Vanni et However, Vezda and Poelt (1987) consid- al. 3654 (CTES, hb. Lücking). Asterothyrium anomalum var. pallidum Lücking & ered Asterothyrium to take an isolated position, Henssen: Costa Rica, Lücking 92-51 (hb. Lücking). although they gave no reasons for their view, and Asterothyrium argenteum Müll.Arg. (type species of later assigned Gyalidea, Linhartia, and Solo- Asterothyrium): Costa