Botanical Studies (2010) 51: 269-275. SYSTEMATICS Sinosenecio yilingii (Asteraceae), a new species from Sichuan, China YingLIU1,2andQin-ErYANG1,* 1Key Laboratory of Plant Resources Conservation and Sustainable Utilization, South China Botanical Garden, Chinese Academy of Sciences, Xingke Road, Tianhe District, Guangzhou 510650, China 2State Key Laboratory of Systematic and Evolutionary Botany, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China (ReceivedJuly6,2009;AcceptedMarch23,2010) ABSTRACT. Sinosenecio yilingiiY.Liu&Q.E.Yang,anewspeciesfromSichuan,China,isdescribed andillustrated.ThenewspeciesissimilartoS. homogyniphyllus(Cumm.)B.Nord.,butdiffersinthetaller stature,theleavesradicalandcauline,oftenreniform,occasionallybroadlyovate,glabrousorverysparsely pubescentabove,thepetiolesproximallyandthepeduncledistallydenselysericeous,thecapitulasolitaryand terminal,andthephyllaries11-13.Itssomatickaryotypeisformulatedas2n=56m+4sm,givingachromo- somenumberof2n=60.PhotographsofbothS. yilingiiandS. homogyniphyllus,linedrawings,distribution map, and light microscope (LM) microphotographs of floral characters of S. yilingiiareprovided. Keywords:Asteraceae;Chromosomenumber;Karyotype;Newspecies;Senecioneae; Sinosenecio yilingii. INTRODUCTION In the course of making a comprehensive survey ofthespecimensofthegenusSinosenecioB.Nord. (Senecioneae-Asteraceae)depositedinChineseherbaria forthefirstauthor’sPh.D.projectonthesystematics andevolutionofthisgenus,afruitingcollection,Gui- ling Chu 3052(IBSC,PE)(Figure1),madefromMeili River, Baoxing County, Sichuan Province, China, caughtourattention.Thiscollectionhadbeenpreviously identifiedasS. homogyniphyllus(Cumm.)B.Nord., andcitedunderthisnamebyJeffreyandChen(1984). Uponacloserexamination,however,wefoundthatthe collectiondiffersmarkedlyfromS. homogyniphyllusin havingleavesradicalandcauline(vs.radical),thepetioles proximallyandthepeduncledistallydenselysericeous (vs.yellowish-brownvillous).InJune2007andMay 2009,wemadetwobotanicalexpeditionstoBaoxing County and collected successfully flowering and fruiting specimensoftheplantinquestion.Wefoundthattheplant issimilartoS. homogyniphyllus inpostureandepappose achenes,butdiffersinthetallerstature(10-40cmvs. 10-25cm),theleavesradicalandcauline(vs.radical), oftenreniform,occasionallybroadlyovate(vs.often broadlyovate-orbicular,occasionallyreniform),glabrous orverysparselypubescentabove(vs.sparselyvillous), thepetiolesproximallyandthepeduncledistallydensely Figure 1. Gui-ling Chu 3052(PE),collectedfromBaoxing County,Sichuan,China.Thiscollection,previouslymisidenti- *Correspondingauthor:E-mail:[email protected];Tel: fied as Sinosenecio homogyniphyllus,representsanewspecies, 86-20-37094273;Fax:86-20-37094273. S. yilingii. 270 Botanical Studies, Vol. 51, 2010 sericeous(vs.yellowish-brownvillous),thecapitula Habitu et pappo nullo species nova haec similis Sino- alwayssolitaryandterminal(vs.solitaryorseveralin senecioni homogyniphyllo (Cumm.) B. Nord., sed planta terminalsubumbelliformcorymbs),andthephyllaries altiore, 10-40 cm alta, caule foliato, foliorum laminis reni- 11-13(vs.7-10).Therefore,weconcludedthattheplant formibus vel interdum late ovatis, supra glabris vel inter- representsahithertoundescribedspecies. dum sparsissime pubescentibus, petiolis basi et pedunculo in superiore parte dense sericeo, capitulis singularibus, NEW SPECIES involucri phyllariis 11-13 differt. Subscapigerousherb,stolonsabsent.Rhizomes2-3mm Sinosenecio yilingiiY.Liu&Q.E.Yang,sp.nov.— indiameter.Stemssolitaryorsometimesseveral,erect, TYPE:CHINA.Sichuan,BaoxingCounty,MeiliRiver, 10-40cmtall,simple,sparselysericeousorlatergla- alt.ca.2,200m,streamsidealongmarginofdeciduous brescentintheupperpart,denselysericeousatthebase. broad-leavedforests,17May2009,Ying Liu & Tao Leaves3-6,radicalandcauline,long-petiolate;lamina Deng 2009069(holotype:IBSC;isotypes:HAST,PE). reniformorsometimesbroadlyovate,1.7-5.5×2-6.5cm, 藝林蒲兒根 Figures2,3 palmatelyveined,marginrepandordentatewithmucro- Figure 2. Sinosenecio yilingii Y. Liu & Q. E. Yang. A, Habit; B, Base of petiole; C, Phyllary; D, Ray floret; E, Disc floret; F, Style- arms;G,Anther(FromYingLiu & Tao Deng 2009069andQin-er Yang, Qiong Yuan & Ying Liu 947,bothatIBSCandPE). LIU and YANG — Sinosenecio yilingii, a new species from China 271 nulateteeth,apexobtuseorsometimesacute,basedeeply 6-7-veined. Disc florets many; corolla ca. 4 mm long, tube cordatetocordate,subcoriaceoustomembranous,green ca.3mmlong,limbcampanulate;lobesovate-lanceolate. todarkgreen,nitidabove,pale-greenbeneath,glabrous Anthersca.2mmlong,baseobtuse,appendagesovate- orsometimesverysparselypubescentonbothsurfaces; oblong.Stylearmsca.1mmlong,apextruncate.Achenes petioles4-9cmlong,sparselysericeousorlaterglabres- obovoid-cylindrical,1.5mmlong,smooth,glabrous.Pap- centintheupperpart,denselysericeousatthebase.Up- pusabsent. percaulineleavessmaller,withshorterpetioles.Capitula Additional specimens examined.CHINA:Sichuan, solitary,terminal;pedunclesparselysericeousorlater BaoxingCounty,MeiliRiver,inwoods,30Jun1936,Gui- glabrescentinthelowerpart,denselysericeousintheup- ling Chu 3052(BM,IBSC,PE);thesamelocality,alt.ca. perpart.Involucreobconic,ecalyculate,7-10×5-7mm. 2100m,streamsidealongmarginofdeciduousbroad- Phyllaries11-13,uniseriate,oblongoroblong-lanceolate, leavedforests,26June2007,Qin-er Yang, Qiong Yuan & 7-10×1.5-2.5mm,apexacuminateoracute,subglabrous, Ying Liu 947(IBSC,PE). apex fimbriate-ciliate, herbaceous, green. Ray florets ca. Etymology. ThisspeciesisnamedinhonorofProfessor 13;corollatubeca.2.5mmlong,glabrous;raysyellow, Yi-LingChen,InstituteofBotany,ChineseAcademyof oblong-elliptic,ca.10×3mm,apically3-denticulate, Figure 3.Sinosenecio yilingiiY.Liu&Q.E.Yang.A,Posture;B,Capitulum;C,Florets;D,Trichomesofpetiole(left)andpeduncle (right);E,Leaves,abaxialside(left)andadaxialside(right);F,Habitat(AllfromYingLiu & Tao Deng 2009069,HAST,IBSC,PE). 272 Botanical Studies, Vol. 51, 2010 Sciences,whohasmadeoutstandingcontributionstothe taxonomyoftheChineseAsteraceae. Phenology.FloweringfromMaytoJune;fruitingfrom JunetoJuly. Distribution, habitat and status.Sinosenecio yilingii iscurrentlyknownonlyfromonepopulationfoundin aravineinBaoxingCounty,SichuanProvince,China (Figure4),growingingrassesoronrocksofstreamside alongmarginofdeciduousbroad-leavedforestsatan altitudeofca.2,200mabovethesealevel.Ifthisistruly theonlypopulation,thenaccordingtotheIUCNred listcategoriesandcriteria,version3.1(IUCN,2001),S. yilingiishouldbecategorizedasacriticallyendangered species(CR).Perhapsthemostseriousthreattothe Figure 5. Anther endothecial cell wall thickenings (A) and fila- species’survivalliesintheongoinghabitatdestruction mentcollar(B)ofSinosenecio yilingii.A. Polarandradialthick- throughmining. enings;B,Uniformlysizedcells(AllfromQin-er Yang, Qiong Yuan & Ying Liu 947,IBSC,PE). Floral micromorphological characters.Forobservation of the anther endothecial cell wall thickenings and filament collar of Sinosenecio yilingii,headswereboiled Chromosome cytology.Forchromosomeobservation, in distilled water for 3 min, and then fixed with Carnoy I roottipswerepretreatedwith0.1%colchicinefor3h (glacialaceticacid:absoluteethanol=1:3).Maturedisc before being fixed in Carnoy I (glacial acetic acid: absolute florets removed from the fixed heads were dehydrated in ethanol=1:3),thenmaceratedina1:1mixtureof45% 70%ethanolfor30minandthenin99%ethanolfor1h aceticacidand1MHClat60°Cfor3min,stainedand beforetheyweretreatedwith5%NaOHovernight.The squashedinCarbolfuchsin. anthertissuewasisolatedfromthefloretsontheslide, Intheinterphasenuclei,afewdarklystainedcondensed flooded with 50% glycerol and a cover slip was applied. bodieswereobserved,buttheirboundarieswerenot Samples were then examined at 200× (filament collar) and clear,becausetheotherpartwasalsostainedfairlywell 400× (endothecial cell wall thickenings) magnification by butunevenly(Figure6A).Theprophasechromosomes lightmicroscopyandphotographed. displayedadistinctlycontinuouscondensationpattern Theendothecialcellwallthickenings inSinosenecio (Figure6B).Themetaphasechromosomeswerecounted yilingiiwerestrictlypolar(Figure5A),acharacter tobe2n=60(Figure6C).Basedonthenomenclature foundtooccurinsomemembersofSinoseneciosect. ofchromosomesofLevanetal.(1964),Sinosenecio Sinosenecio (JeffreyandChen,1984).Inthemembersof yilingiihad56median-centromeric(m)and4submedian- Sinoseneciosect.PhyllocaulonC.Jeffrey&Y.L.Chen, centromeric(sm)chromosomes(Figure6D),i.e.2n= theendothecialcellwallthickeningsareradialorradial 60=56m+4sm.Thechromosomeschangedgradually andpolar(JeffreyandChen,1984;Zhangetal.,2008;Liu fromthelargesttothesmallestinsize,andthekaryotype et al., 2009). As indicated in Figure 5B, its filament collar washighlysymmetrical.Thechromosomenumber2n consistedofuniformlysizedcells,conformingtooneof =24reportedbyLiu(1999)forS. homogyniphyllus, thediagnosticcharactersofthisgenus(Nordenstam,1978; thecloserelativeofS. yilingii,mayrepresentawrong JeffreyandChen,1984). count, most likely owing to misidentification of material, asthematerialexaminedbyhimwasobtainedasagift fromananonymousperson. Wehavere-examinedthe chromosomesofS. homogyniphyllusandrevealedthe numberas2n=60.Theresultsofacomprehensivesurvey ofthechromosomenumbersinthegenusSinosenecio will bereportedinaseparatepaper(YingLiu&Qin-erYang, inprep.). Notes.Sinosenecio yilingiicanbereadilyreferred tosubsect.PhalacrocarpaC.Jeffrey&Y.L.Chen, sect.Sinosenecio,basedonitsstrictlypolaranther endothecialcellwallthickeningsandepapposeachenes. Itssubscapigerouspostureandepapposeachenes, at first glance,