῏῕῍ΐῐ῔ῌ (48), pp. 91ῌ137, 2012 ῒ 3 ῎ 28 ῑ Mem. Natl. Mus. Nat. Sci., Tokyo, (48), pp. 91ῌ137, March28, 2012 A Synopsis of the Lichen Genus Usnea (Parmeliaceae, Ascomycota) in Taiwan Yoshihito Ohmura Department of Botany, National Museum of Nature and Science, 4ῌ1ῌ1 Amakubo, Tsukuba, Ibaraki 305ῌ0005, Japan E-mail: [email protected] Abstract. A key to the 40 taxa in the genus Usnea in Taiwan is presented. Usnea articulata is new to Taiwan. Usnea mutabilis is excluded from the lichen flora of Taiwan. Photographs of diagnostic features are also provided for the species that have not been adequately illustrated previously based on the Asian materials. Orthographical errors were corrected in U. shimadae and U. pseudogatae. Key words: flora, lichenized Ascomycota, morphology, secondary substances, taxonomy, TLC. accepted taxa (39 species and one variety) of Introduction the genus Usnea in Taiwan, along with the The genus Usnea (Parmeliaceae, Ascomy- diagnostic features with images which have not cota) consists of ca. 300 species, and is widely been adequately illustrated previously. distributed from polar zones to tropical area (Kirk et al., 2008). Diagnostic features of the Materials and Methods genus include a fruticose thallus with a cortex, medulla, and a cartilaginous central axis, and This study is primarily based on Ohmura the presence of usnic acid in the cortex. (2001) and Ohmura et al. (2010) and the Monophyly of the genus has been confirmed by herbarium specimens deposited in the National molecular phylogenetic methods using the Museum of Nature and Science, Tokyo (TNS) taxa having these synapomorphic features and the National Museum of Natural Science, (Ohmura, 2002; Ohmura & Kanda, 2004; Taichung (TNM), as well as specimens col- Articus, 2004; Wirtz et al., 2006), although lected mainly by the author between 2008 and Articus (2004) elevated several infrageneric 2010. All specimens examined are deposited in groups to generic level (i.e., Dolichousnea, TNS otherwise indicated. Eumitria, Neuropogon,andUsnea). Morphological observations were made The Usnea flora of Taiwan was primarily using a dissecting microscope or a bright field summarized by Ohmura (2001) who revised microscope. The diameter of branch was meas- the former studies in this area made by ured using a well-developed thicker branch. Zahlbruckner (1933), Motyka (1936ῌ1938), The ratios of thickness of the cortex, medulla, and Asahina (1956, 1963, 1965a, 1965b, 1967a, and axis for the branch were measured follow- 1967b, 1967c, 1967d, 1968a, 1968b, 1969a, ing the method of Clerc (1984). The minimum- 1969b, 1969c, 1969d, 1970, 1972a, 1972b). average-maximum values of them are shown in After that, several taxa were added to the the description. Cross sections of thallus were Usnea flora in Taiwan (Aptroot et al., 2002; cut by hand with a razor blade, and observed Clerc, 2004; Ohmura et al., 2010). after mounting in GAW (glycerin : ethanol : This paper provides a practical key to 40 water, 1:1:1). 92 Yoshihito Ohmura Fig. 1. TLC spots of major lichen substance detected from Taiwanese Usnea (solvent B). Control of Rf classes 2 (stictic acid), 4 (norstictic acid) and 7 (atranorin) is shown in the leftmost column. The spot of usnic acid is shown in all columns as a standard except in a control column. Spot of diagnostic substance is encicled with a bold line. Fatty acid is encircled with a dashed line (fatty acid is visible only in wet condition of TLC plate). Spot color after heating (110ῌ, 10 min) with 10% H2SO4 is shown. 2dPsoῌ2ῌ-O-demethylpsoromic acid, 4dBarῌ4-O-demethylbarbatic acid, Atῌatranorin, Bae ῌbaeomycesic acid, Barῌbarbatic acid, Capῌcaperatic acid, ConStῌconstictic acid, Difῌdi#ractaic acid, Eumῌeumitrin, Evῌevernic acid, Fumῌfumarprotocetraric acid, Galῌgalbinic acid, Lecῌ lecanoric acid, Menῌmenegazziaic acid, Norῌnorstictic acid, ProCῌ protocetraric acid, Psoῌ psoromic acid, Salῌsalazinic acid, Sqῌsquamatic acid, Sticῌstictic acid, Thamῌthamnolic acid, Usῌusnic acid, Zeoῌzeorin, and unidentified substances (US1, US2, US3, and US5; see in Ohmura, 2001). Lichen substances were examined using thin Usnic acid is a constant substance in the layer chromatography (TLC) (Culberson & cortex of Usnea spp. although it varies in Johnson, 1982). Solvent Bsystem (hexane : amount depending on the place of thallus. methyl tert-butyl ether : formic acid, 140: 72 : Atranorin is sometimes detected as an accessa- 18) was used for all TLC analyses. A summary ry substance in various species such as U. of lichen substances detected from Taiwanese baileyi, U. fuscorubens, U. rubicunda, U. Usnea taxa is shown in Fig. 1. rubrotincta, and U. trichodeoides, and consid- Morphological and chemical characteristics ered to be no taxonomic value for distinguish- for distinguishing taxa are followed by ing species in the genus. Salazinic acid is one of Ohmura (2001). common substances in Taiwanese Usnea taxa, and often follows norstictic (minor), pro- tocetraric (faint trace) and constictic acids Results and Discussion (faint trace) (Fig. 1A). It is found in e.g. U. baileyi, U. cornuta subsp. cornuta, U. dasaea, Lichen substances in Taiwanese Usnea U. dendritica, U. fuscorubens, U. glabrata, U. Diagnostic substances and several accessary glabrescens, U. himalayana, U. masudana, U. substances detected in Taiwanese Usnea by nidifica, U. orientalis, U. pangiana, U. TLC are summarized by schematic illustration pseudogatae, U. rubrotincta (Race 1), U. in Fig. 1. shimadae, U. trichodeoides, and U. wasmuthii. Synopsis of the Genus Usnea in Taiwan 93 Fig. 2. Red pigmentation patterns in Taiwanese Usnea. A. Wine red pigment present in the cortex-side of medulla (U. baileyi). B. Strawberry pink pigment present in the cortex-side of medulla (U. ceratina). C. Red pigment in both subcortical thin layer and parts of cortex (U. bicolorata). D. Red pigment in cortex (U. rubicunda and U. rubrotincta). A. Fistulose axis. B-D. Solid axis. Galbinic acid (Fig. 1B) is found in U. dasaea with fumarprotocetraric acid in U. tricho- (Race 2) and U. shimadae, and its TLC spot deoides (Race 2), the occurrence or concentra- might become smear if its concentration is tion of the substance seems to be variable. high. Stictic acid usually follows constictic, Protocetraric acid accompany with fumarpro- menegazziaic, and norstictic acids (Fig. 1C). It tocetraric acid was detected in Taiwanese ma- is found in e.g. U. aciculifera, U. bismolliuscula, terials of U. trichodeoides. Both succinprotoce- U. pectinata, U. pygmoidea, U. rubicunda, and traric and protocetraric acids might be present U. rubrotincta (Race 2). Unidentified sub- in U. trichodeoides (Race 2) when they would stances of US1 and US2 (Ohmura 2001) are be checked by High Performance Liquid diagnostic substances for U. hakonensis.The Chromatography (HPLC). Psoromic (major) TLC spots repel water on the plate and exhibit- and 2ῌ-O-demethylpsoromic acids (minor) ing a lemon yellow color after heating (Fig. 1D). (Fig. 1H) are detected as accessary substances Norstictic acid (Fig. 1E), without salazinic acid, from U. rubicunda in Taiwan. Barbatic acid stictic acid, US1 and US2, is detected in e.g. U. (major) usually follows 4-O-demethylbarbatic angulata, U. fulvoreagens, U. praetervisa, and acid (minor) (Fig. 1I). Barbatic acid without U. sinensis. Protocetraric acid (Fig. 1F) with- di#ractaic acid is detected from U. dendritica, out other distinct substances is detected from U. longissima (Race 1), U. pangiana (Race 2), U. cornuta subsp. brasiliensis and U. hesperina. and U. wasmuthii (Race 2). Di#ractaic acid Fumarprotocetraric acid (Fig. 1G) is found in (major) usually follows small amount of U. articulata and U. trichodeoides (Race 2). barbatic, 4-O-demethylbarbatic, baeomycesic, Although Ohmura (2001) reported the pres- and squamatic acids (Fig. 1J). It is found in U. ence of succinprotocetraric acid accompany ceratina, U. di#racta, U. fulvoreagens (Race 2), 94 Yoshihito Ohmura and U. longissima (Race 2). Evernic acid 5b. Terminal and subterminal branches elon- (major) follows lecanoric acid (minor) (Fig. gated; sorediate fibrils abundant on 1K), and it is only found in U. longissima branches; soralia present on both fibrils (Race 3). Thamnolic acid (Fig. 1L) is a diag- and thick branches nostic substance for U. florida and U. sub- ῌῌῌῌῌῌῌῌU. rubrotincta Stirt. floridana. Caperatic acid (Fig. 1M) is known 6a. Cortex fragile on main branches, decor- as a constant substance in U. angulata, U. ticate or areolately corticate; thallus nipparensis, and U. sinensis. Unidentified sub- “fish-bone” like appearance with nu- stance of US5 (Ohmura, 2001) (Fig. 1N) is a merous perpendicular fibrils on elon- medurally red pigment of U. ceratina. Zeorin gated branches ῌῌῌῌῌῌῌῌῌ7 (Fig. 1O) is found as a constant substance in 6b. Cortex stable, consistent on the branches; U. baileyi and U. fulvoreagens. Eumitrins (A1, thallus not as above ῌῌῌῌῌῌῌ9 A2 and B) are detected in U. baileyi which 7a. Thallus with black to dark brown base; species usually follows salazinic and norstictic annular-pseudocyphellae absent; stictic acids, although eumitrins A1 and Bare variable acid present; saxicolous or corticolous in amount (Fig. 1O). ῌῌῌῌU. pectinata Taylor (Fig. 24) 7b. Thallus with concolous or pale base; Key to the Usnea taxa in Taiwan annular-pseudocyphellae present espe- 1a. Red pigment present in thallus (including cially near the base of thallus; stictic scattered small red spots on cortex) acid absent; corticolousῌῌῌῌῌῌ8 (Fig. 2) ῌῌῌῌῌῌῌῌῌῌῌῌ2 8a. Salazinic or fumarprotocetraric