Cladonia Chlorophaea Research Articles

Orcinol-Type Depsides and Depsidones in the Lichens of the Cladonia chlorophaea Group (Ascomycotina, Cladoniaceae)

Five new lichen products-the depsidones stenosporonic and divaronic acids and the meta-depsides hyperhomosekikaic, submerochlorophaeic, and subpaludosic acids--are reported from species of the Cladonia chlorophaea group and from the genera Neofuscelia, Parmelia, Ramalina and Physcidia. These compounds fill previously vacant positions in four chemically homologous series of depsidones and meta-depsides involving 3- and 5-carbon sidechains. The chemical struc- tures are based upon chromatographic correlations, and those of the depsidones are confirmed by mass spectrometry. In the lichen fungi natural-product variation is so closely correlated with morphological variation that chemical characters have been intimately involved in systematics for more than a century. In general, each morphotype is chemically constant throughout its range and upon all substrates. Chemistry con- sequently becomes a key character in even routine taxonomic identifications. In some morphotypes, however, multiple chemical races have evolved, producing a noncongruence of chemistry and form that is the source of controversy regarding the sig- nificance of natural-product variation as a marker of evolutionary divergence. Most chemically vari- able morphotypes consist of only a few chemotypes that may be characterized by biosynthetically closely related compounds. There are, however, a few ex- amples of morphs with many chemical races rep- resenting a broad spectrum of biosynthetic differ- ences. An analysis of morphotypes with such extensive chemical diversity should lead to an eval- uation of the relative significance of levels of chem- ical divergence. The Cladonia chlorophaea group, in the broadest sense in which this name has been applied, offers one of the most complex examples of natural-prod- uct differentiation among the lichen-forming fungi. In its worldwide distribution, which includes all continents except Antarctica, it consists of at least 14 major chemotypes. Its remarkable chemical di- versity involves some 35 secondary products dis- tributed among four major categories: 1) orcinol- type para-depsides, meta-depsides and depsidones; 2) a 3-orcinol para-depside and 3-orcinol depsi- dones; 3) the unique aliphatic ester bourgeanic acid;

Cladonia chlorophaea sens. lat. in Southeastern Australia

The distribution of species within the Cladonia chlorophaea group in southeastern Australia has been determined from a chemical examination of 148 specimens. The commonest species is Cladonia merochlorophaea Asah.; Cladonia grayii Merr. ex Sandst. does not appear to occur in the area studied. Cladonia homosekikaica Nuno is reported for the first time from Australia. The Cladonia chlorophaea group contains several morphologically similar species which are differentiated on the basis of their constituent lichen acids. Five species of this group occur in Australia viz. C. chlorophaea (Flirke ex Sommerf.) Spreng. (fumarprotocetraric acid); C. cryptochlorophaea Asah. (cryptochlorophaeic acid ? fumarprotocetraric acid with traces of paludosic acid); C. merochlorophaea Asah. (merochlorophaeic and 4-O-methyl- cryptochlorophaeic acids ? fumarprotocetraric acid with traces of homosekikaic and cryp- tochlorophaeic acids); C. conoidea Ahti (atranorin and fumarprotocetraric acid) and C. homosekikaica Nuno, with homosekikaic and fumarprotocetraric acid. A recent chemical examination of 148 specimens of C. chlorophaea sens. lat. collected in southeastern Australia (excluding Tasmania) gave the results shown in Table 1. The specimens were collected from 31 locations as shown in Fig. 1. The altitudes of the collection sites ranged from 2200 m (Mt. Kosciusko, N.S.W.) to 50 m (Gladesville, N.S.W.). No collections were made from north and west of the 500 mm isohyet; C. chlorophaea was not found in this dryer area (Rogers & Lange 1972). Acetone extracts of the specimens were examined by thin-layer chromatography (Culberson 1972) and the separated com- pounds were detected with sulphuric acid (Culberson 1972) and MBTH (Archer 1978). Grayanic acid, for use as a reference compound, was extracted from Gymnoderma mela- carpum (Wilson) Yoshimura (Chester & Elix 1980). The results in Table 1 show that the most frequently collected species was C. merochloro- phaea; 58% of the specimens contained fumarprotocetraric acid compared to 89% in North America (Bowler 1972); C. merochlorophaea var. novochlorophaea Sipman (Sipman 1973) was not found. C. chlorophaea sens. str. formed 30% of the specimens examined and a further 13% were C. cryptochlorophaea; 75% of these contained fumarprotocetraric acid compared to 82% in North America. The less common species were C. conoidea and C. homosekikaica; the latter species is reported from Japan (Nuno 1975). The apparent absence of C. grayi from southeastern Australia is in marked contrast to the distribution of the species within the C. chlorophaea group reported from the Northern Hemisphere (Nourish & Oliver 1976), particularly from North Carolina (Kristinsson 1971) and the southern Appalachians (Dey 1978) where it was the most common species found. Cladonia merochlorophaea, the most common species in southeastern Australia, occurs relatively infrequently in North America. Cladonia grayi is not reported from South Aus- tralia (Filson & Rogers 1979) or Tasmania (Wetmore 1963) but is reported from South America (Dey 1978) and New Zealand (Martin 1958). However, a recent chemical ex-

Physiography and Fumarprotocetraric Acid Production in the Cladonia chlorophaea Group in North Carolina

Physiography and Fumarprotocetraric Acid Production in the Cladonia chlorophaea Group in North Carolina

Morphological and Chemical Correlations in the Cladonia chlorophaea Complex

Measurements of granules from within the podetial cups of different chemical variants of the Cladonia chlorophaea complex in North Carolina show clear correlation between granule size and certain chemical characters. The results support the view that the replacement of cryptochlorophaeic acid by grayanic acid in this group is taxonomically more significant than the presence or absence of fumarprotocetraric acid. In the species tested, the soredia of C. conista are the smallest, those of C. perlomera and C. grayi are intermediate, and those of C. cryptochlorophaea are the largest. The Cladonia chlorophaea group was treated by Sandstede (1931) as including two species-C. chlorophaea (Flirke) Spreng., containing fumarprotocetraric acid and consequently distinguished by a bitter taste, and C. grayi Merr. ex Sandst., lacking fumarprotocetraric acid and consequently with a mild taste. Asahina (1940) discovered grayanic acid, cryptochlorophaeic acid, and merochlorophaeic acid in this group and divided the complex into four species: Cladonia grayi, C. cryptochlorophaea Asah., and C. merochlo?rophaea Asah. are characterized by the presence of grayanic acid, cryptochlorophaeic acid, and merochlorophaeic acid, respectively, while C. chlorophaea is considered to have fumarprotocetraric acid only. Within each of the first three species, the presence or absence of fumarprotocetraric acid is generally ignored from taxonomic considerations, but Asahina treated such fumarprotocetraric acid variants as forms. Although these four species are the most common ones of the chlorophaea group, many other variants have been recorded (Ahti, 1966; Culberson & Kristinsson, 1969). The morphologic variability has generally been considered to be the same within all the chemically different races in the complex. Ahti (1966), however, indicated some morphological differences between some of the plants called C. merochlorophaea and those of the other chemical species, and Krog (1968) claimed that the rangiformic acid variant in Alaska has a characteristic morphology. Wetherbee (1969) has demonstrated substrate specificity in some of the chemical species in Michigan. The present paper deals with the morphology and distribution of the chemical variants of the C. chlorophaea group in North Carolina. Since a preliminary survey indicated that there was a significant difference in the size of the soredia in the podetial cups between some of the chemical variants, a large-scale survey was made. Other 1 This study was supported by grant GB-6041X from the National Science Foundation. I thank Dr. William Louis Culberson for his interest in this work and for linguistic corrections and Dr. Chicita F. Culberson for her advice on the identification of the lichen substances. 2 Department of Botany, Duke University, Durham, North Carolina 27706. Present address: NMttlirugripasafnit Q Akureyri, P.O. Box 580, Akureyri, Iceland. This content downloaded from 157.55.39.153 on Mon, 19 Sep 2016 04:46:55 UTC All use subject to http://about.jstor.org/terms 14 THE BRYOLOGIST [Volume 74 100 Cladonia grayi PD+ s ---C. grayi PD?. C. cryptochlorophaea PD+ . .... .. ........ C. cryptochlorophaea PDo/ .... C)' I 0 100 200 300p LLI N A

CLADONIA ECMOCYNA NYL. - INVESTIGATIONS ON THE ONTOGENY

SUMMARY The ontogeny of the podetium and the apothecium in Cladonia ecmocyna Nyl. is investigated morphologically and anatomically. The podetia are formed by generative tissue. Sexual organs and apothecia are only formed at the top of grown podetia. The development is the same as in Cladonia chlorophaea, described by Jahns 1969. The phyllocladia are formed by growth of the algal layer of the podetium. In the process a piece of the cortex is torn free at the basal side of the primordium of the phyllocladium and bent upwards. Phyllocladia are also formed at the margin of old cups. The phyllocladia of old, rotten podetia can assume the function of the thallus horizontalis. New podetia emerge from them. The tissue of the apothecium is not fundamentally determinant. It was observed that on the disc of an apothecium a phyllocladium had been formed by the subhymenial tissue. On this phyllocladium a pycnidium was found.

Studies on the Cladonia chlorophaea Group: A New Species, a New meta-Depside, and the Identity of "Novochlorophaeic Acid"

The new species Cladonia perlomera, known from eight localities in eastern North Carolina, produces merochlorophaeic and perlatolic in addition to a new meta-depside, 4-O-methylcryptochlorophaeic The isolation and proof of structure of the new compound is described. Re-examination of C. merochlorophaea shows that it also produces 4-O-methylcryptochlorophaeic acid, in addition to merochlorophaeic acid, which was originally found in this species. Four specimens of a variant previously thought to represent a rare strain of C. merochlorophaea characterized by containing novochlorophaeic acid with or without merochlorophaeic actually contain a mixture of sekikaic and homosekikaic acids and no merochlorophaic Extraction of an as yet unnamed chemical variant of the C. chlorophaea group yielded homosekikaic Imbricaric was found in two specimens of the C. chlorophaea group tested. Sekikaic and imbricaric were not previously known in the genus Cladonia, and homosekikaic and perlatolic are new to the C. chlorophaea group. Perhaps no chemically variable species group of lichens is better known to lichenologists than the Cladonia chlorophaea complex. These ubiquitous plants with their familiar goblet-shaped podetia exist as a series of perplexing chemical variants with slight associated morphological characters-or none at all. The group has recently been summarized by Thomson (1968) and discussed by Ahti (1986) and Krog (1968). The major chemical variants of the C. chlorophaea group are listed in Table 1. The purpose of the present paper is to report several new chemical variants of the C. chlorophaea complex, to describe a new species in the group, to give the proof of structure of a new meta-depside produced by the new species, and to report the identity of novochlorophaeic acid. 1 This research was supported by a grant (GM-08345) from the Division of General Medical Sciences, National Institutes of Health, and one (GB-6041X) from the National Science Foundation. We thank Dr. Teuvo Ahti and Dr. John W. Thomson for fragments of the specimens used to study novochlorophaeic acid and Dr. David Rosenthal for the mass spectra. 2 Department of Botany, Duke University, Durham, North Carolina 27706. This content downloaded from 157.55.39.102 on Mon, 03 Oct 2016 05:17:13 UTC All use subject to http://about.jstor.org/terms 432 THE BRYOLOGIST [Volume 72