Abstract：? Based on the specimens collected from Yunnan Province， the lichen genus Schizotrema Mangold & Lumbsch is reported as new to China， with the species Schizotrema guadeloupense （Hale） Mangold & Lumbsch. Among Graphidaceae， the genus is characterized by its ascomata with concentrically layered margins composed of carbonized excipular remnants of older hymenia; the proper exciple is fused to indistinctly free， periphysoids are usually present， and the ascospores are transversely septate to muriform. The species S. guadeloupense is also new to Asia. In addition， notes of other five species in the genus are also given， with ecology and distribution， and worldwide key to species of Schizotrema is described in the present paper. All these results provide basic data information for the taxonomy of the family Graphidaceae.

Key words： taxonomy， lichenized fungi， Ostropales， new record

CLC number：? Q949Document code：? A

摘要：? 該文報道了中國文字衣科地衣一新記錄屬——裂孔衣屬（Schizotrema Mangold & Lumbsch）及其1個新記錄種，即瓜島裂孔衣 [Schizotrema guadeloupense （Hale） Mangold & Lumbsch]，標本來自云南。該屬主要特征為地衣體殼狀，樹皮生，具子囊盤類或色盤衣類的子囊果，子囊果具再生層狀邊緣，固有盤被融合或不明顯，具側(cè)生側(cè)絲，子囊孢子橫隔透鏡或磚壁型。瓜島裂孔衣也是亞洲新記錄種。此外，該文還對裂孔衣屬其他5種的生態(tài)分布特征進行了描述，并提供了該屬世界范圍檢索表。以上結(jié)果為文字衣科地衣的分類學(xué)研究提供了基礎(chǔ)資料。

關(guān)鍵詞： 分類學(xué)， 地衣型真菌， 厚頂盤目， 新記錄

The genus Schizotrema Mangold & Lumbsch belonging to Graphidaceae， Ostropales Ostropomycetidae， Lecanoromycetes， Pezizomycotina， Ascomycota， only comprises six species in thelotremoidGraphidaceae（Kalb， 2009; Mangold et al.， 2009; Lumbsch et al.， 2010; Rivas Plata et al.， 2010， 2012， 2013; Lücking et al.， 2016）. It was rather recently established to accommodate species with rounded ascomata and a layered margin formed by concentrically arranged remnants of carbonized excipular tissue from older hymenia. In recent years， some small genera of graphidaceae have been reported in China， such as thelotremoid genera Chapsa （Xu & Jia， 2015） and Myriotrema （Xu et al.， 2016）， and graphioid genera Carbacarthographis （Jia et al.， 2017; Liu et al.， 2018）， Fissurina （Jia et al.， 2018） and Leiorreuma （Wang et al.， 2015）. Based on specimens collected from Yunnan Province， this genus is here newly reported from China， with a single species， Schizotrema guadeloupense.

1Materials and Methods

The specimens are deposited in Fungariuml of the College of Life Sciences， Liaocheng University， China （LCUF）. OLYMPUS SZX16 and TECH XTS30D dissecting microscopes， and OLYMPUS BX53 compound microscope were used for the morphological and anatomical studies， and the lichen substances were detected using standardized thin layer chromatography （TLC）. These were conducted as described in Jia & Wei （2016）.

2Descriptions

Schizotrema Mangold & Lumbsch， in Mangold， Elix & Lumbsch， Fl. Australia 57： 657 （2009）.

Type species： Schizotrema zebrinum Mangold.

Thallus corticolous， crustose， pale grey to yellowishgreen， smooth to rough. Photobiont trentepohlioid. Apothecia erumpent to prominent，± rounded，apothecioid but usually with a narrow pore， regenerating with concentrically layered excipula and laterally covered by thalline layer， concolorous with the thallus; excipula more or less carbonized， periphysoids usually present; new hymenia formed from below the previous hymenia; ascospores transversely septate or muriform， nonamyloid.

Chemistry： βorcinol depsidones， or no lichen substances present.

Notes： Schizotrema is characterized by erumpent to prominent， apothecioid ascomata with regenerating hymenia resulting in a ± distinctly layered margin， with an apically free proper exciple that is dark brown to carbonized， a strongly conglutinated hymenium， distinct lateral paraphyses， ascospores transversely septate to muriform， hyaline to yellowish or brownish at late maturity. The genus grows on bark and wood and is found worldwide， with a concentration of species in Australia， mainly in cooltemperate and warmtemperate rainforests， less commonly in subtropical and tropical habitats. Schizotrema is most similar to Topeliopsis Kantvilas & Vězda， but differs in the carbonized excipula. Several other genera of thelotremoid Graphidaceae form lateral paraphyses， viz. Acanthotrema Frisch， Chapsa A. Massal.， Melanotopelia Lumbsch & Mangold， Pseudoramonia Kantvilas & Vězda， Schizotrema Mangold & Lumbsch， Thelotrema Ach.， and Topeliopsis Kantvilas & Vězda. except for Melanotopelia and Schizotrema， have a noncarbonized excipulum， and Melanotrema differs from Schizotrema in the simple， nonlayered excipulum. Crutarndina Parnmen， Lücking & Lumbsch agrees with Schizotrema in the layered excipulum but only has the apical portion carbonized and both genera are phylogenetically unrelated.

Schizotrema guadeloupense （Hale） Mangold & Lumbsch， in Mangold， Elix & Lumbsch， Fl. Australia 57： 657 （2009）. —Thelotrema guadeloupense Hale， Phytologia 26： 416 （1973）; type： Guadeloupe， Parc National de Guadeloupe， M. E. Hale 31633;holotype： US！

Fig. 1

Thallus partially endoperidermal， pale greyish green to pale olive， dull to glossy， smooth to rough， corticate; cortex 15-20 μm thick; photobiont layer continuous.

Ascomata rounded to somewhat irregular， erumpent， 0.5-0.8 mm diam.， regenerating with layered margins. Disc usually hidden by excipular material， pore 0.2-0.4 mm diam.， rounded to angular， formed by the apices of the innermost excipular tissue. Proper exciple usually apically free， dark brown to carbonized and usually containing periderm cells. Hymenium 150-200 μm high; periphysoids conspicuous. Epithecium indistinct. Asci 8spored. Ascospores richly muriform， A， B. Thallus （Scales = 1 mm）; C. Asci with ascospores （Scale = 50 μm）; D， E. Asci with ascospores （Scale = 20 μm）.

ellipsoid to fusiform， with rounded to subacute ends， hyaline to brownish at late maturity，nonamyloid，40-70? μm × 15-20 μm， locules rounded to angular; ascospore wall thin， nonhalonate， I-.

Chemistry： Stictic acid （major） and constictic acid （minor）.

Notes： Schizotrema guadeloupense is similar to S. schizolomum （Müll. Arg.） Mangold & Lumbsch， but the latter species has larger ascospores （60-180? μm × 20-40 μm） and produces salazinic acid. S. cryptotrema （Nyl.） Rivas Plata & Mangold is also somewhat similar， but differs in the rather cryptic ascomata and the psoromic acid chemistry.

Ecology and Distribution： In China， the species grows on bark， known from tropical primeval forest of Mountain Daweishan in Yunnan Province， Southwest China. Associated lichens include species of Graphis. It was previously reported from the Antilles （Guadeloupe）， Argentina， Australia （including Tasmania）， and New Zealand （Mangold et al.， 2009; Lumbsch et al.， 2010）， and is new to China and to both continental and tropical Asia.

Specimens examined： China. YunnanGejiu City， Manhao Town， Malongdi， 1 280 m， 23 November 2011， Z. F. Jia 11488， 11493 （LCU）.

Notes on other five species of Schizotrema in the world

Schizotrema cryptotrema （Nyl.） Rivas Plata & Mangold， in Rivas Plata， Lücking， Sipman， Mangold， Kalb & Lumbsch， Lichenologist 42（2）： 184 （2010）. —Thelotrema cryptotrema Nyl.， Annls Sci. Nat.， Bot.， sér. 57： 319 （1867）.

Schizotrema cryptotrema is characterized by ascomata morphological cryptic， with indistinctly layered; ascospores muriform; presence of psoromic acid.

Ecology and Distribution： On bark. French Guiana， Brazil， Costa Rica （Nylander， 1867; Redinger， 1936）， Venezuela （Kalb， 2009）.

Schizotrema flavolucens （Sipman） Lücking， in Lücking， Mangold & Lumbsch， Herzogia 29： 506 （2016）. — Myriotrema flavolucens Sipman， Trop. Bryol. 6： 5 （1992）.

Schizotrema flavolucens is characterized by conspicuous， layered ascomata with carbonized proper exciple; asci 8spored; ascospores hyaline， nonamyloid， 18-25? μm × 7-11 μm， transversely septate， with （3-） 5 （-6） locules; presence of lichexanthone.

Ecology and Distribution： On twigs in humid savannah vegetation on sandstone flats at tableland. Veneznela （Sipman， 1992）.

Schizotrema schizolomum （Müll. Arg.） Mangold & Lumbsch， in Mangold， Elix & Lumbsch， Fl. Australia 57： 657 （2009）. — Leptotrema schizoloma Müll. Arg.， Nuov. Giorn. Botan. Ital. 21： 49 （1889）.

Schizotrema schizolomumis characterized by regenerating， distinctly layered and carbonized ascomata; 1-4 （-6） spored asci; large， thin walled， mainly nonamyloid， muriform ascospores sized 60-180? μm × 20-40 μm; presence of salazinic acid or no lichen substances .

Ecology and Distribution： On bark and wood in cooltemperate to warmtemperate rainforests.Tasmania， New Zealand， Argentina， Australia （Mangold et al.， 2009; Lumbsch et al.， 2010）.

Schizotrema subzebrinum Mangold， in Mangold ， Elix & Lumbsch， Fl. Australia 57： 657 （2009）.

Schizotrema subzebrinum is characterized by inconspicuous， erumpent， distinctly layered and distinctly carbonized ascomata; asci 8spored; ascospores hyaline， nonamyloid， 20-35 μm × 7-10 μm， submuriform， with 10-14 × 1-2 （-3） locules; absence of lichen substances.

Ecology and Distribution： On bark in warmtemperate rainforest. NSW （Mangold et al.， 2009）.

Schizotrema zebrinum Mangold， in Mangold， Elix & Lumbsch， Fl. Australia 57： 657 （2009）.

Schizotrema zebrinum is characterized by conspicuous， layered ascomata with carbonized thick proper exciple; asci 6-8spored; ascospores hyaline， nonamyloid， 30-80? μm × 6-11 μm， transversely septate， with 12-22 locules; presence of variable chemistry containing stictic acid， constictic acid， conprotocetraric acid， protocetraric acid， and so on （major to absent）.

Ecology and Distribution： On bark in cooltemperate to warmtemperate and tropical montane rainforests. Australia （Mangold et al.， 2009）， New Zealand （Lumbsch et al.， 2010）.

Worldwide key to species of Schizotrema1a. Ascospores transversely septate2

1b. Ascospores （sub） muriform 3

2a. Ascospores 30-80 μm × 6-11 μm， with 12-22 locules; stictic or fumarprotocetraric acids present

Schizotrema zebrinum Mangold

2b. Ascospores 18-25 μm × 7-11 μm， with （3-）5（-6） locules; lichexanthone present

S. flavolucens （Sipman） Lücking

3a. Ascospores submuriform， 20-35 μm × 7-10 μm; no lichen substancesS. subzebrinum Mangold

3b. Ascospores muriform， 35-180 μm × 15-40 μm; chemistry variable4

4a. Ascospores 60-180 μm × 20-40 μm; salazinic acid or no lichen substances

S. schizolomum （Müll. Arg.） Mangold & Lumbsch

4b. Ascospores 35-80 μm × 15-30 μm; psoromic or stictic acid or cinchonarum unknowns5

5a. Stictic acid （major） and constictic acid （trace）; apothecia with distinctly layered margins

S. guadeloupense （Hale） Mangold & Lumbsch

5b. Psoromic acid present; apothecia morphologically cryptic， with indistinctly layered margins

S. cryptotrema （Nyl.） Rivas Plata & Mangold

AcknowledgmentsThe first author is very grateful to Dr. Harrie Sipman for his help with TLC studies and also thanks the Botanic Garden and Botanical Museum （BGBM）， Free University of Berlin， for its hospitality during a research visit in Germany. The collaborative study of family Graphidaceae was also done with the project of Shandong Provincial Education Association for International Exchanges.

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（責(zé)任編輯 何永艷）