Introduction
The family Graphidaceae, with 1200 species (now also including Thelotremataceae), is one of the largest groups of crustose lichens and has a wide distribution in tropical regions. The family belongs to Ostropales, which is the largest order within Ostropomycetidae (Lumbsch & Huhndorf Reference Lumbsch and Huhndorf2007; Kirk et al. Reference Kirk, Cannon, Minter and Stalpers2008; Mangold et al. Reference Mangold, Martín, Lücking and Lumbsch2008). Staiger (Reference Staiger2002) revised the spore-based generic system established by Müller Argoviensis (Reference Müller Argoviensis1880a , Reference Müller Argoviensis b , Reference Müller Argoviensis1882) for the family Graphidaceae, and reintroduced several genera with a revised concept, including the genus Platygramme Fée. Platygramme is a tropical and subtropical taxon, which is characterized by lirelliform ascomata, an apically or laterally carbonized proper exciple often wedge-like in appearance, an inspersed hymenium and greyish to pale brown transversely septate or muriform ascospores.
In a study of the genus Platygramme for the Flora Lichenum Sinicorum, Miao et al. (Reference Miao, Jia, Meng and Wei2007) reported two species from China, namely P. discurrens (Nyl.) Staiger, which was also reported as Graphis discurrens from Hong Kong (Nylander Reference Nylander1863), and P. pachyspora (Redinger) Staiger, described as a new record for China. Subsequently, Platygramme muelleri was added by Li (Reference Li2010). In the present paper, Platygramme pudica and P. platyloma are reported from China for the first time, and the two species Platygramme hainanensis and P. lueckingii are described as new to science.
Materials and Methods
The lichen specimens were examined with a dissecting microscope (TECH XTS-20 and AIGO Digital Viewer GE-5) and a compound microscope (OLYMPUS CHB-213) for morphological and anatomical studies. Hand-cut sections mounted in tap water were routinely examined. Amyloidity of the ascospores was tested using Lugol's solution. Spot tests with KOH (20%) were performed on the thallus surface and on thin thallus sections. The chemistry was determined by thin-layer chromatography (TLC) using standard methods.
Key to the species of Platygramme from China
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1 Ascospores with transverse septa, 5–25(–30)×5–8 µm ... Platygramme discurrens (Nyl.) Staiger
Ascospores submuriform or muriform ... 2
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2(1) Ascospores 1 per ascus, longer than 100 µm when mature ... 3
Ascospores 2–8 per ascus, shorter than 100 µm when mature ... 5
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3(2) Echinocarpic acid present, ascospores 150–180×18–25 µm; disc concealed, labia covered by thallus ... Platygramme pudica (Mont. & Bosch.) M. Nakan. & Kashiw.
Lichen compounds absent ... 4
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4(3) Lirellae conspicuously open, disc visible; ascospores 110–160×18–25 µm ... Platygramme muelleri (A. W. Archer) Staiger
Lirellae closed to slightly open, disc concealed, with thick labia; ascospores 120–180×25–35 µm ... Platygramme platyloma (Müll. Arg.) M. Nakan. & Kashiw.
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5(2) Ascospores submuriform, 45–80×12–18 µm; disc very narrow ... Platygramme pachyspora (Redinger) Staiger
Ascospores muriform, shorter than 50 µm; disc concealed, labia covered by thallus ... 6
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6(5) Ascospores 8 per ascus, 30–50×6·5–13·0 µm ... Platygramme hainanensis Z.F. Jia & Kalb
Ascospores 2(4) per ascus, 35–45×11·0–15·5 µm ... Platygramme lueckingii Z.F. Jia & Kalb
The Species
Platygramme hainanensis Z.F. Jia & Kalb sp. nov.
MycoBank No: MB801119
Sicut P. australiensis sed sporis minoribus differt.
Typus: China, Hainan Island, Mt. Wuzhishan, 18°92′N, 109°68′E, alt. 680 m, 28 August 2008, coll. Jing Li HN081281 (HMAS-L—holotypus).
Fig. 1. Platygramme hainanensis (Jing Li HN081281). A, habit; B, cross-section of an apothecium; C, ascus containing ascospores; D, ascospore. Scales: A=1 mm; B=50 µm; C=50 µm; D=50 µm. In colour online.
Thallus corticolous, crustose, pale white to greenish, unevenly thickened, tightly attached to the substratum.
Apothecia elongate, 1–10 mm long, 0·2–0·4 mm wide, simple or rarely slightly branched, prominent, with basal thalline margin, black, curved and straight, often rounded at the ends, not striate, scattered over the thallus, labia covered with thin white pruina; disc concealed. Proper exciple apically to laterally carbonized. Epithecium 8–10 µm thick, brownish. Hymenium colourless, inspersed, 130–180 µm high, I−. Paraphyses unbranched, filiform, up to 1·0–1·5 µm wide. Asci cylindrical, 110–150×15–25 µm, 8-spored. Ascospores greyish brown, oblong to ellipsoid, muriform, 8–9×1–3-locular, 30–50×6·5–13·0 µm, I+ red-brown. Hypothecium brownish, 8–15 µm high.
Chemistry
No lichen compounds detected.
Etymology
The specific epithet ‘hainanensis’ refers to the type locality of the new species, Hainan Island.
Remarks
Platygramme hainanensis is characterized by the conspicuous, closed, prominent, apically-carbonized lirellae with closed disc and thick labia, the muriform ascospores (30–50 µm long), and by the absence of lichen compounds. It is distinguished from P. australiensis Staiger & Malthes-Leicht by smaller ascospores.
Additional specimens examined. China: Hainan: Mt. Wuzhishan, 790 m, 2009, Li Jing HN216 (HMAS-L); 730 m, 2009, Li Jing HN233 & HN 233-1 (HMAS-L).
Platygramme lueckingii Z.F. Jia & Kalb sp. nov.
MycoBank No: MB801120
Sicut P. hainanensis sed ascis 2-sporis differt.
Typus: China, Hainan Island, Mt. Jianfengling, 18°71′N, 108°83′E, alt. 740 m, 1 October, 2008, Li Jing HN081395 (HMAS-L—holotypus).
Fig. 2. Platygramme lueckingii (Li Jing HN081395). A, habit; B, cross-section of an apothecium; C, ascospores. Scales: A=1 mm; B=50 µm; C=50 µm. In colour online.
Thallus corticolous, crustose, yellowish green to greenish, thin, tightly attached to the substratum.
Apothecia elongate, lirelliform, 1–5 mm long, 0·3–0·4 mm wide, simple, often branched, erumpent to prominent, with basal thalline margin, black, curved and straight, often rounded at the ends, not striate, scattered over the thallus, labia covered with white pruina; disc concealed. Proper exciple apically wedge-shaped, carbonized. Epithecium 8–10 µm thick, brownish. Hymenium colourless, inspersed, 110–160 µm high, I−. Paraphyses unbranched, filiform, up to 1·0–1·5 µm wide. Asci cylindrical, 90–110×13–25 µm, 2-spored. Ascospores greyish, oblong to ellipsoid, muriform, 8–9×1–3-locular, 35–45×11·0–15·5 µm, I+ weakly blue. Hypothecium brownish, 8–15 µm high.
Chemistry
No lichen compounds detected.
Etymology
The new species is named in honour of our colleague and friend Dr Robert Lücking for his many contributions to the knowledge of Graphidaceae.
Remarks
Platygramme lueckingii is characterized by the conspicuous, closed, erumpent to prominent, apically carbonized lirellae with closed disc and thick labia, the muriform ascospores (35–45 µm long), and the absence of lichen products. It is distinguished from P. hainanensis by the 2-spored asci. At present the new species is known only from Mt. Jianfengling, Hainan Island, which is situated in the tropical parts of China.
Platygramme discurrens (Nyl.) Staiger
Biblioth. Lichenol. 85: 361 (2002).—Graphis discurrens Nyl., Ann. Sci. Nat., Bot. sér. 4, 19: 358 (1863b).—Phaeographina discurrens (Nyl.) Müll. Arg., Flora, 65: 604 (1882).
Fig. 3. Platygramme discurrens (Jing Li HN081281). A, habit; B, cross-section of an apothecium. P. muelleri (Jing Li HN081281). C, habit; D, cross-section of an apothecium. Scales: A & C=1 mm; B=50 µm; D=50 µm. In colour online.
Thallus corticolous, yellow-green, thin, surface shiny, flat to somewhat rough.
Apothecia lirelliform, greyish black, often branched, conspicuous, prominent, 1–6 mm long and 0·1–0·3 mm wide, lips closed, with thin white pruina, without thalline margin. Disc concave, very narrow. Proper exciple convergent, apically carbonized. Hymenium inspersed, 70–100 µm high. Ascospores 8 per ascus, pale brown, elongate, with transverse septa only, 4–7-locular, 15–25(–30)×5–8 µm, I+ red-brown.
Chemistry
Stictic acid (major) and constictic acid (trace).
Remarks
Platygramme discurrens is characterized by the closed, conspicuously prominent, apically carbonized lirellae with closed disc and thick labia, the small ascospores (15–25 µm long) with transverse septa, and the presence of stictic acid. The type specimen of this species was collected in Hong Kong and originally described in the genus Graphis (Nylander 1863), but later transferred to the genus Platygramme by Staiger (Staiger 2002).
Specimens examined. China: Hainan: Mt. Wuzhishan, 680–800 m, 2009, Li Jing HN220-1, HN226-1 (HMAS-L). Yunnan: Menglun County, 560 m, 1981, Jiang Yu-Mei 1015-3 (HMAS-L); 650 m, 1981, Jiang Yu-Mei 949 (HMAS-L). Fujian: Mt. Wuyi, Wanmulin, 250 m, 2004, Jia Ze-Feng FJ360 & Wei Xin-Li 0189 (LHS).
Platygramme muelleri (A. W. Archer) Staiger
Biblioth. Lichenenol. 85: 364 (2002).—Phaeographina muelleri Archer, Telopea 8(4): 473 (2000).—Phaeographina caesiopruinosa var. monospora Müller Arg., Bull. Herb. Boissier 3(7): 322 (1895c).
Thallus corticolous, greenish yellow, thin, surface matt, somewhat rough.
Apothecia lirelliform, black, single and sometimes branched, conspicuous, sessile, 1·0–2·5 mm long, 0·3–0·6 mm wide, lips inconspicuous, with a distinct thalline margin. Disc open, black, with a thin pruina. Proper exciple apically carbonized, wedge-shaped. Hymenium inspersed, 150–200 µm high. Ascospores 1 per ascus, pale brown, elongate, densely muriform, 28–40×4–7-locular, 110–160×18–25 µm, I+ red-brown.
Chemistry
No lichen compounds detected.
Remarks
Platygramme muelleri is characterized by the conspicuous, open, apically carbonized lirellae with opened disc and delicate labia, the large muriform ascospores (110–160 µm long), and the absence of lichen compounds. It was reported from China by Li (Reference Li2010).
Specimens examined. China: Yunnan: Weixi County, 1900 m, 1981, Wang Xian-Ye et al. 3749 (HMAS-L). Hainan: Mt. Wuzhishan, 700 m, 2009, Li Jing HN09096 (HMAS-L); Mt. Jianfengling, 2008, Li Jing HN081330 & HN081400 (HMAS-L).
Platygramme pachyspora (Redinger) Staiger
Biblioth. Lichenol., 85: 364 (2002).—Phaeographis pachyspora Redinger, Ark. Bot. 27 A (3): 77 (1935).
Fig. 4. Platygramme pachyspora; A, habit; B, cross-section of an apothecium; C, ascospores. P. platyloma; D, habit; E, cross-section of an apothecium; F, ascospore. P. pudica; G, habit; H, cross-section of an apothecium; I, ascospore. Scales: A, D & G=1 mm; B, E & H=50 µm; C, F & I=50 µm. In colour online.
Thallus corticolous, grey-greenish, thin, surface matt, smooth to rough.
Apothecia lirelliform, greyish black, single, conspicuous, erumpent to sessile, 1–7 mm long, 0·2–0·4 mm wide, with thalline margin. Disc very narrow. Proper exciple convergent, laterally carbonized, wedge-shaped. Hymenium inspersed, 150–170 µm high. Ascospores 8 per ascus, pale brown, elongate, submuriform, 10–12×1–2-locular, (45–)50–80×12–18 µm, I+ red-brown.
Chemistry
No lichen compounds detected.
Remarks
Platygramme pachyspora is characterized by the wedge-shaped, carbonized lateral exciple with closed disc and thick labia, the submuriform ascospores (45–80 µm long), and the absence of lichen compounds. It was first reported from China by Miao (Miao et al. 2007).
Specimen examined. China: Fujian: Mt. Wuyi, 250 m, 2004, Jia Ze-Feng FJ 370 (LHS).
Platygramme platyloma (Müll. Arg.) M. Nakan. & Kashiw.
Bull. Natn. Sci. Mus., Tokyo, Ser. B, 29: 89 (2003).— Phaeographis platyloma Müll. Arg., Flora, 65: 389 (1882).
Thallus corticolous, yellow-greenish, thin, surface matt, rough.
Apothecia lirelliform, conspicuous, scattered, prominent, black, single, 1·0–5·0 mm long and 0·4–0·6 mm wide, with lateral thalline margin. Proper exciple convergent, apically to laterally carbonized, wedge-shaped. Disc very narrow. Hymenium inspersed, 180–230 µm tall. Ascospores 1 per ascus, brownish, elongate-ellipsoid, densely muriform, 120–180×25–35 µm, I+ red-brown.
Chemistry
No lichen compounds detected.
Remarks
Platygramme platyloma is characterized by conspicuous lirellae with the proper exciple laterally wedge-shaped and carbonized, a narrow disc and thick labia, large muriform ascospores (120–180×25–35 µm), and the absence of lichen substances. It occurs in Australia, Indonesia and Japan (Nakanishi et al. Reference Nakanishi, Kashiwadani and Moon2003; Archer Reference Archer2006). It is first reported from China in the present paper.
Specimens examined. China: Fujian: Jianou County, Wanmulin, 420–430 m, 2007, Meng Qing-Feng FJ1020 & FJ1221 (LHS).
Platygramme pudica (Mont. & Bosch) M. Nakan. & Kashiw.
Bull. Natn. Sci. Mus., Tokyo, Ser. B, 29: 89 (2003).—Graphis pudica Mont. & Bosch, in Junghuhn, Plantae Junghuhnianae, 4: 474 (1855).
Thallus crustose, corticolous, upper surface matt, rough.
Apothecia lirelliform, numerous, single, curved or sinuous, 1·0–5·0 mm long, 0·5–0·8 mm wide, prominent, black, with lateral thalline margin. Proper exciple convergent, laterally carbonized, red-brown in the base. Hymenium inspersed, 180–250 µm tall. Ascospores 1 per ascus, pale brownish, elongate or ellipsoid, muriform, 20–25×5–6-locular, 150–180×18–25 µm, I+ red-brown.
Chemistry
Echinocarpic acid (major) and conechinocarpic acid (minor).
Remarks
Platygramme pudica is characterized by conspicuous lirellae with a laterally carbonized proper exciple and closed and thickish labia, large muriform ascospores (120–180 µm long) and the presence of echinocarpic acid. It occurs in Australia, Indonesia and Japan (Nakanishi et al. Reference Nakanishi, Kashiwadani and Moon2003; Archer Reference Archer2006). This species is reported here from China for the first time.
Two species reported from Fujian province, Phaeographina elaeoplaca A. Zahlbr. and Ph. granulans A. Zahlbr., with large fuscescent muriform ascospores and sessile lirellae, and with concealed disc and thick labia (Zahlbruckner Reference Zahlbruckner1932), appear to belong in Platygramme. They are very similar to Platygramme pudica, but differ slightly in ascospores size, with the ascospores of Phaeographina elaeoplaca being 110–120×30–32 µm and P. granulans 140–160×29–31 µm (Zahlbruckner Reference Zahlbruckner1932). As we have not yet investigated the types of these species, we refrain from formally proposing them as synonyms.
Specimens examined. China: Fujian: Jianou County, Wanmulin, 420 m, 2007, Meng Qing-Feng FJ856 (LHS); 600 m, 2007, Li Jing FJ1000 (LHS).
The authors are grateful to Dr Alan W. Archer and Dr Robert Lücking for help with identifications, and for valuable comments and discussions. The National Natural Science Foundation of China (No. 31093440 and 31270066) and the Ministry of Science and Technology of China (No. 2006FY110500–5) are thanked for their financial support.
