Botanical Studies (2009) 50: 107-113. taXONOMY Sinosenecio baojingensis (Asteraceae), a new species from Hunan, China YingLIU1,Gong-XiCHEN2,andQin-ErYANG3,* 1State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China 2College of Biology and Environmental Science, Jishou University, Hunan 416000, China 3South China Botanical Garden, Chinese Academy of Sciences, Xingke Road, Tianhe District, Guangzhou 510650, China (ReceivedMarch18,2008;AcceptedNovember7,2008) ABSTRACT. Sinosenecio baojingensisY.Liu&Q.E.Yang,anewspeciesofAsteraceaefromnorthwestern Hunan,China,isdescribedandillustrated.Itschromosomenumber(2n=48)isreportedhere.Thenew speciesissimilartoS. euosmusandS. denticulatusinhavingleafystemsandsmoothachenesbearinga pappus.ItdiffersfromS. euosmusinitsmuchtallerstature(75-150cmvs.20-75cm),theovate-cordate outlineofitsleaves(vs.ovatetobroadlyovate),itsdenticulate(vs.crenate)margin,anditsmuchlargersize (12-20×10-18cmvs.2-5×3-6cm).FromS. denticulatusitdiffersinitssometimestallerstature(75-150 cmvs.35-140cm),andovate-cordate(vs.reniform)leaves,denticulate(vs.dentate)margin,anditslarger size(12-20×10-18cmvs.4-14×6-17cm).Frombothitdiffersinhavingundivided(vs.moreorless lobed)leavesandbasallyexpandedbutneverauriculate(vs.auriculate)petioles.Acolorplate,linedrawings, distributionmap,lightmicroscope(LM)photomicrographsoffloralcharacters,andakeytoaidinthe identification of S. baojingensisanditspossiblerelativesareprovided. Keywords: Asteraceae;Chromosomenumber;Floralmicrocharacters;Senecioneae;Sinosenecio baojingensis. INTRODUCTION For the first author’s Ph.D. project on the systematics andevolutionofthegenus Sinosenecio,wecarriedout SinosenecioB.Nord.(Senecioneae-Asteraceae)is abotanicalexpeditionthroughoutcentralandwestern agenusofca.38species,allofwhichoccurinChina, ChinafromApriltoJuly,2007.InnorthwesternHunan, Indochina,andKorea(JeffreyandChen,1984;Janovec inavalleynearMt.Ludong,BaojingXian,wecollected andBarkley,1996;Chen,1999;Liu,2000;Zhangetal., plantssimilartoS. euosmus(Hand.-Mazz.)B.Nord.andS. 2008),exceptforonespecies,S. newcombei(Greene) denticulatusJ.Q.Liu,butwhichdifferedbyhavinglarger, J.P.Janovec&T.M.Barkley,disjunctlydistributedin ovate-cordate,undividedleavesandbasallyexpanded theQueenCharlotteIslands,BritishColumbia,Canada butneverauriculatepetioles.Wedeterminedthatthey (JanovecandBarkley,1996).Thegenusischaracterized representanundescribedspecies,whichisheredescribed. byusuallypalmatelyveined,petiolateleaveswiththe laminadistinctfromthepetiole,ecalyculateinvolucres,a Sinosenecio baojingensisY.Liu&Q.E.Yang,sp.nov.— campanulate limb of the disc florets, the polarized orradial TYPE:CHINA:Hunan, BaojingCounty,Mt.Ludong, patternoftheantherendothecialcellthickenings,anda 270m,grassyplaces,3April2007,Q. E. Yang, Qiong filamentcollarwithuniformlysizedcells(Nordenstam, Yuan & Ying Liu 554 (holotype, PE). 保靖蒲兒根 1978;JeffreyandChen,1984).China,where37species Figures1,2 havebeenrecorded(Chen,1999;Liu,2000;Zhanget Species nova haec similis Sinosenecioni euosmo al.,2008),isundoubtedlythemostimportantcenterof (Hand.-Mazz.)B.Nord.etS. denticulatoJ.Q.Liucaule differentiationforthegenus.Itisnoteworthythatmost foliato,acheniislaevibuspappopraeditis,abilloplanta speciesofSinosenecioinChinahavearathernarrow multoaltiore,75-150cmalta,foliorumlaminismulto distribution,andthus,aspointedoutbyJeffreyandChen majoribus,12-20cmlongis,10-18cmlatis,abhocplanta (1984),discoveryofnewspeciesisexpectedasbotanical vulgoaltiore,foliorumlaminismultomajoribus,ab explorationproceedsinthiscountry. ambobusfoliisindivisis,ambituovato-cordatis,petiolis tantumbasidilatatis,haudauriculatisdiffert. *Correspondingauthor:E-mail:[email protected];Tel: Herbs, rhizomatous,stolonsabsent.Stemsolitary, 86-20-37094273. erect,75-150cmtall,ca.15-20mmindiam.atbase, 108 Botanical Studies, Vol. 50, 2009 Figure 1. Sinosenecio baojingensis Y. Liu & Q. E. Yang. A, Habit; B, Phyllary; C, Ray floret; D, Disc floret; E, Stamen; F, Style-arms. (AllfromQin-er Yang et al. 554,PE). LIU et al. — Sinosenecio baojingensis, a new species from China 109 Figure 2. Sinosenecio baojingensis Y. Liu & Q. E. Yang. A, Posture; B, Leaf; C, Inflorescence; D, Capitula; E, Florets. (All from Qin- er Yang et al. 554,PE). 110 Botanical Studies, Vol. 50, 2009 simple,villousorlanate.Leavesradicalandcauline. m Radicalleavespetiolate;petioles14-28cmlong,sparsely open lanate,baseexpanded;laminaovate-cordate,12-20 on 270 margin × 10-18cm,palmatelyveined,basecordate,margin expanded ca. radial glabrous 10-18 grass denticulate,apexacute,lowersurfacepalegreenor × and whitishlanate,uppersurfacegreenandsparselyvillous; deep a.s.l undivided, denticulate upperstemleavessmaller,withshorterpetioles.Capitula hillside, S. baojingensis 75-150 12-20 Present March-April 48 Hunan Obviously Polar Smooth, Ovate-cordate, many,inapicalcompoundcorymbs;peduncles1.5-4 In cm long, sparsely villous. Involucres campanulate, a.s.l ecalyculate,6-7 × 6-9mm.Phyllariesca.13,uniseriate, m oblong-lanceolate,6-7×1.5-2mm,apexacuminate, lobe puberulous, herbaceous, green. Ray florets ca. 13; corolla 2800 tube3mmlong,glabrous;raysyellow,oblong-elliptic,ca. middle radial glabrous 8mm × 3-4 mm, apically 3-denticulate, 4-7-veined. Disc expanded 1-6 shrubs, the and × floretsmany;corolla5mmlong,tube3mmlong,limb campanulate;lobesovate-lanceolate.Anthersca.1.5mm 2-3-dentate with S. fangianus Present June-July Unknown Sichuan 30-85 Slightly 1.5-6 Polar Papillate, Reniform, 7-9-palmatifid, long,baseobtuse,appendagesovate-oblong.Stylearms Under ca.1mmlong,apextruncate.Achenescylindrical,1.5mm long,smooth,glabrous.Pappuswhite,3mmlong. margin Additional specimens examined. CHINA.Hunan, deeply a.s.l woods, BaojingXian,Mt.Ludong,invalley,3April2007,Dai- m in gui Zhang & Liang Xu 070403017(JIU). expanded shallowly or radial glabrous 4-4.5 Etymology. Thespecific epithet‘baojingensis’ is and × sometimes derivedfromthetypelocality,BaojingCounty,Hunan mucronulate-dentate Province,China. and 5-7-palmatilobed, 3,300-4,300 S. sungpanensis Present June-July 48 Sichuan 40-50 Obviously 3-3.5 Polar Papillate, Reniform, Meadows Phenology. FloweringfromMarchtoApril;fruiting May. Distribution, habitat and status. Sinosenecio 5-7-lobed, baojingensisisknownfromonlyonepopulationina valleyinBaojingXian,Hunan,China(Figure3),growing regularly in deep grass near paddyfields on an open hillside at an Madarogyne altitudeofca.270m.Ifthisistrulytheonlypopulation, shallowly radial rather glabrous then according to the IUCN red list categories and 6-17 and × criteria,version3.1(IUCN,2001),S. baojingensisshould subsection margin becategorizedasacriticallyendangeredspecies(CR). mucronulate-denticulate a.s.l in S. denticulatus 35-140 Auriculate Present May-June Unknown Sichuan 4-14 Polar Smooth, Reniform, Damp places in valley, 1,500 m Damp places in valley, Becausethesiteiswithinanareaofhumanactivity,the most serious threat to the species’ survival lies in the and species potentialhabitatdestructionthroughminingandfarming. moist related a.s.l shallowly deeply m and 5-8-palmatilobed, to meadows, ovate, deeply radial shallowly glabrous 2,400-4,000 broadly margins, 3-6 and × sometimes margin mucronulate-dentate places, 20-75 2-5 S. euosmus Auriculate Present June-August Unknown Sichuan Polar Smooth, Ovate, Forest ) Sinosenecio baojingensis n (2 of thickenings number distribution achenes cell of (cm) Comparison petioles (cm) of shape size Figure 3. Distribution of Sinosenecio baojingensis (▲)in HunanProvince,China. Height Leaf Base Chromosome Geographical Leaf Table 1. Table Pappus Flowers Habitat Endothecial Epidermis LIU et al. — Sinosenecio baojingensis, a new species from China 111 Floral micromorphological characters. Toobserve ThechromosomenumberofSinosenecio baojingensis anther endothecial cell thickenings and the filament collar wasdeterminedtobe2n=48(Figure5). Sincethebasic ofSinosenecio baojingensis,weboiledtheheadsin numberofthegenusisx=12(Liu,1999;Zhangetal, distilled water for 3 min, and then fixed them in Carnoy’ 2008),S. baojingensisisatetraploid.Thechromosome ssolution(glacialaceticacid:absoluteethanol=1:3). numberofoneofitspossiblerelatives,S. sungpanensis,is Maturediscfloretswereremovedfromthefixedheads 2n=48(unpublisheddata). andtransferredto70%ethanolfor30min.,thento99% Sinosenecio baojingensiscanbereadilyreferredto ethanolfor1hbeforetheywereimmersedin5%NaOH sectionPhyllocaulonC.Jeffrey&Y.L.Chensubsection for 24 h. The anther tissue was isolated from the florets Madarogyne C. Jeffrey &Y. L. Chen based on the ontheslide,floodedwith50%glycerolandacover polarandradialpatternoftheantherendothecialcell slipwasapplied.Sampleswerethenexaminedat200× thickenings,thepresenceofcaulineleaves,andthe (filament collar) and 400× (endothecial cell thickenings) glabrousovariesandachenes.AsshowninTable1,S. magnification by light microscopy and photographed. baojingensisissimilartoS. euosmusandS. denticulatus TheantherendothecialcellthickeningsofSinosenecio withinthesubsectioninhavingleafystemsandsmooth baojingensisarepolarandradial(Figure4A),conforming achenesbearingapappus,butdiffersfromtheformerin totheresultsreportedpreviouslythatendothecialcell itstallerstature(75-150cmvs.20-75cm),leavesovate- thickeningsarestrictlypolar,polarandradialorradialin cordateinoutline(vs.ovatetobroadlyovate),margin otherspeciesofthegenus(JeffreyandChen,1984).As denticulate(vs.crenate),andmuchlargersize(12-20 showninFigure4B,thenewspecieshasuniformlysized