Three New Records of Rhizocarponfrom China

WANG Weicheng，ZHAO Zuntian

（College of Life Science，Shandong Normal University，Ji’nan 250014，China）

RhizocarponRamond ex DC.（Rhizocarpaceae）is agenus of about 200species worldwide，and 36species have been found in China［1－3］.It is usually characterized by areolate or rimose thallus，black lecideine apothecia between areoles，Rhizocarpon－type asci，1－septate to muriform ascospores with halo，brown hypothecium，anastomosing and branched paraphyses［4］.

In this paper，three new records ofRhizocarponfrom China are reported.R.atrovirellumandR.furaxare both collected from Xinjiang Mt.Tianshan No.1Glacier in 2011and 2012，whereasR.simillimumis collected from Xinjiang Changji City August First Forest Farm in 2012.

1 Materials and methods

The examined specimens were collected from Xinjiang，China and preserved in SDNU （the Lichen Section of Plant Herbarium，Shandong Normal University）.Their morphological and anatomical characters were examined under a stereo－microscope（Olympus SZ）and a polarizing microscope（Olympus CX21）.Color reactions （spot tests）were made using standard methods［5］.The chemical constituents were identified using thin layer chromatography（TLC）.Photos were taken under Olympus SZX16and BX61with DP72.

2 Results

2.1 Rhizocarpon atrovirellum （Nyl.）Zahlbr.，Cat.Lich.Univers.4：347（1926）.PlateⅠ，Fig.1－4

Thallus parasitic onAspicilia；areolate，usually small，only a few millimeters in diameter，sometimes up to 1.5cm diam.；medulla I－；prothallus absent；areoles bright－yellow，angular，up to 0.8 mm diam.，flat to slightly convex.Apothecia usually developed in the areoles，which surround them like a collar，up to 0.7mm diam.，slightly convex，margin indistinct.Epihymenium and exciple brownblack，K＋red；hymenium colorless，up to 75μm diam.；hypothecium browm，K－.Ascospores 8per ascus，2 to 6－celled，ellipsoid，dark－brown，halonate，（15－20）×（7.5－10）μm.

Chemistry：Medulla K－，C－，P－.Chemical constituent：rhizocarpic acid.

Habitat：On siliceous rocks.

Notes：Rhizocarponviridiatrumis similar toR.atrovirellumbut differs in having muriform ascospores with six to ten cells，roundish and highly convex areoles and larger thallus（up to 2cm diam.）.R.atrovirellumwas reported from central Europe［6］and is new to China.

Specimens examined：Xinjiang，Tianshan Mountain，No.1 Glacier，alt.3 750 m，on rocks，27 Aug.2011，Lulu Zhang 20125920；alt.3 800 m，on rock，27 Aug.2011，Lin Li 20126159.

2.2 Rhizocarpon furax Poelt ＆ V.Wirth，Mitt.bot.StSamml.，Münch.8：94（1970）.PlateⅠ，Fig.5－8

Thallus parasitic onLecidea，small，up to 4 mm diam.；medulla I＋violet；prothallus absent；areoles bright－yellow，angular－roundish，up to 0.8 mm diam.，dull，slightly convex.Apothecia black，immersed，up to 0.5 mm diam.，more or less surrounded by an areole collar，flat.Epihymenium and exciple red－brown，K＋red；hymenium colorless，up to 125μm diam.；hypothecium browm，K－.Ascospores 8per ascus，mostly with 3transverse septa，fusiform，blue－green，halonate，（20－25）×7.5μm.

Chemistry：Medulla K－，C－，P－.Chemical constituent：rhizocarpic acid.

Habitat：On siliceous rocks.

Notes：Rhizocarponfuraxis close toR.intermediellumbut the latter has smaller ascospores［（12－21）×（6－10）μm］，distinctly marginate apothecia，angular areoles and non－parasitic thallus（or parasitic only when young）［7］.

Specimens examined： Xinjiang， Tianshan Mountain，No.1 Glacier，alt.3700 m，on rocks，17 Aug.2012，Xin Zhao 20129094，20129069.

2.3 Rhizocarpon simillimum （Anzi.）Lettau，

Hedwigia 52：156（1912）.PlateⅠ，Fig.9～13

Thallus areolate，3cm in diam.；medulla I＋violet；prothallus distinct，black；areoles up to 0.5 mm diam.，dull，contiguous，angular，slightly convex.Apothecia up to 0.7mm diam.，black，epruinose，angular，flat，margin present.Epihymenium and exciple brown－black，K＋red；hymenium colorless to pale brown；hypothecium dark brown；paraphyses branched and anastomosing.Ascospores 8 per ascus，1－septate，olive－green or brown，ellipsoid，halonate，（12.5－16）×6.5μm.

Chemistry：Medulla K－，C－，P－.No lichen substances detected by TLC.

Habitat：On siliceous rocks.

Notes：R.simillimumhas been reported from Europe，North and South America［8］，it is recognized by its amyloid medulla，1－septate small brown and halonate ascospores and dark brown，well developed thallus.R.disporumlooks likeR.simillimumbut has muriform ascospores.

Specimens examined：Xinjiang，Changji，August First Forest Farm，alt.2 100 m，on rock，10 Aug.2012，Xin Zhao 20128966，20128972，20128973，20128980.

PlateⅠ Morphological and anatomical structures of the newly reported taxa.

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