Studies On Foliar Anatomy Of Polygonaceae From Jiangxi

Leaf morphology and anatomy of 44 species and 2 varieties in Polygonaceae from Jiangxi were studied.The results are as follows;1)Characters of lamina transverse section had obvious differences in different genara and could be used as a basis for the classification of genara or sections; The outline had two types;the V-shaped and the W-shaped.2)The cells of epidermis were multiangular and irregular.And their anticlinal walls were straight and sinuate; Viewed from the transaction,epidermal cells of all species,except Polygonum perfolium,of which the epidermal cells were circular, were oval or rectangular;3)Several types of stoma apparatus on mature leaves were recognized in this survey;anomocytic type,brachyparacytic-anomocytic type,non-typical anisocytic type,anisocytic type and paralytic type.Stoma apparatus of some plants were mainly paracytic,such as Sect.Polygonum,Sect.Echinocaulon;4)Gland scales were generally recognized on the leave surface of Polygonaceae, and had the same structure in or among different genara or sections,which was first reported at home;5)Many types of hair were observed on the leave epidermis,had specificity in genara or sections;6)Special structures were found on the leave epidermis of some species.For an example,Polygonum nepalense had resin cup,and a small number of species had special epidermal cells,which were large in size and had contents;7)The leaves of almost species(except Polygonum aviculare and Rumex trisetifer)were differentiated into the palisade tissue and the spongy tissue,but the thickness of leaves and percentage of palisade tissue and spongy tissue were different among sections or species; the crystal cells,of which the destructions had difference among genara or sections,were generally existed in Polygonaceae; Secretory sacs were saw under foliar epidermis in some species;8)Most species had 4 vascular bundles with the array of cruciform in the main vein,same 1,2 or 6,a few 10 or more with the array of ring; 9)Bubdle sheaths were universal in the vein of Polygonaceae,and mostly not extended,certain individual bundle sheaths were extended.From the above observations,we considered that;1)In Sect.Echinocaulon, because of the particularity of Polygonum bungeanum,so it was set apart from Sect. Echinocaulon to Sect.Persicaria.2)In Sect.Bistorta,according to the shape of epidermal cells and hair,Polygonum suffultum Maxim.var.tomentosum B.Li.et S.F. Chen var.nov.was sustained.3)Based on special structure such as resin cup,Sect. Cephalophilon was divided into 3 series,and Polygonum nepalense was advised to independently become a sery.4)With the characters of floral modality and the structure of foliar anatomy,Polygonum perfoliatum was set apart from Sect. Echinocaulon,was advised to independently become Sect.Chylocalyx.5)In Persicaria,Polygonum japonicum Meisn.var.conspicuum Nakai.was sustained.6) Based on the characters of mid-ribs and epidermis,Polygonum amphibium was set apart from Sect.Persicaria,was advised to independently become Sect.Amphibium. 7)Based on the structure of foliar anatomy,Rumex acetosella,which was obviously different with other species in Rumex,was sustained to become Subgen.Acetosella.8) Because of paralytic stoma apparatus,1 layer of palisade tissue and special external characteristics,Echinocaulon was sustained.9)Based on the evolution of stoma apparatus and the structure of foliar anatomy,Sect.Echinocaulon was laid on the higher position in the systematical evolution of Polygonum,and Sect.Avicularia and Sect.Cephalophilon were relatively primitive; in the systematical evolution of Polygonaceae,Polygonum was sat on the higher position,Fagopyrum and Rumex were relatively primitive.Based on the structure characters of leaves,the key of sections and genara in Polygonaceae from Jiangxi was layouted.