| Cyperaceae,containing ca.100 genera and 5600 species,is one of the largest family in monocots,and China has more than 800 species belonging to 28 genera.Carex L.,with ca 2000 species,is the largest genus within Cyperaceae,and ca.500 species were recorded in China.Being wide spread,rich species and complex variation,as well as limited collection and scattered-deposited type specimens,the genus Carex is difficult in taxonomic and systematic studies.The section Confertiflorae comprises ca.20 species and mainly distributes in E.Asia.With 16 recorded species till now in China,the taxonomy of sect.Confertiflorae is also difficult to deal with.Based on literature survey,specimen examination,morphological and micromorphological observations on perigynia and achenes,leaf anatomical structure,a taxonomic revision is carried out and the main results are as following:Morphology and micromorphology on the perigynia of 18 species and 2 varieties in sect.Confertiflorae were observed and measured.The prigynium shape is oblong-ovoid,ovoid,obovoid and global-ovoid,rarely global-obovoid,trigonous or inflated-trigonous,and the size ranges from 3 to 4 mm long,apex contracted into medium-sized or long beak,orifice obliquely truncate to 2-lobed with short teeth,rarely 2-lobed with long teeth(C.transversa),distinctly thinly veined,glabrous or rarely short-hispidulous.The perigynium morphology and micromorphology shows steady among different populations within the same species/variety,but distinctive between/among related taxa.The perigynium morphology and micromorphology reveals important taxonomic implications.C.idzuroei and C.hymenodon have the perigynia much longer than those in other member in sect.Confertiflorae,and they could not be ascribed in this section.Morphology and micromorphology on the achenes of 18 species and 2 varieties in sect.Confertiflorae were observed and measured.The achene shape is almostly ovoid,trigonous,rarely obovoid or global-ovoid,and the size ranges from 2 to 2.5 mm long,apex beak and connected with non-thickened style base,whereas C.tenuirostrata has the achenes apex abruptly contracted in a long beak.The epidermal cells are 5 or 6 gonal,regular,with straight anticlinal walls,flat silica platform(C.benkei C.retrofracta slightly convex or convex),and central silica body is single(2 or 3 in C.sclerocarpa)and satellite silica body formally absent.The achene morphology and micromorphology shows steady among different populations within the same species/variety,but distinctive between/among some related taxa.It reveals considerably important taxonomic implications.Micromorphology of leaf anatomy of 16 species and 2 varieties was observed and measured.The cells of adaxial leaf surfaces are oblong,regularly arranged,rarely linear and oblong,or sub-quadrate.The abaxial cells are similar to adaxial ones,but the size of both abaxial and adaxial cells of leaf surfaces are variable.Anticlinal walls of the epidermal cells are almost deeply undulate,while those of C.confertiflora and C.tenuirostrata are undulate.Stoma regularly distributes in abaxial leaf surfaces,silica papillae occurs in the adaxial leaf surface of C.benkei and abaxial leaf surfaces of C.confertiflora and C.tenuirostrata.Trabuculae are occasionally found in adaxial leaf surfaces.The micromorphology of the leaf epidermal cells shows steady among different populations within the same species/variety,but distinctive between/among some related taxa.It reveals some taxonomic implications.Based on morphological and micromorphological observations,a taxonomic revision of sect.Confertiflorae was proposed,and 17 species were recognized.C.subglabra is combined as specific rank,and four names are reduced to synonyms.Lectotypification is designated for C.transversa and C.subtumida,and C.idzuroei and C.hymenodon are considered as the members of sect.Paludosae. |
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