Study On The Sac Epidermis And Achene Micromorphology Of Some Sedge Plants (Cyperaceae)

Carex L.is the largest genus of Cyperaceae,generally perennial herb,with underground rhizomes,stalks triangular,flower-uniform,has 1 female flower or 1 male flower.The female branch of the small spikes has a utricle,and the spikelets are composed of a plurality of spikelets.The utricles are triangular in shape,and the achenes are enclosed in the utricles,and are triangular or flat convex.There are more than 2,000 species in the world,and there are nearly 500 species in China,which are distributed in various provinces and regions across the country.Its categories are massive,which are widely distributed and its characters are widely changes.It is very difficult to classify and identify.There are still many problems in the classification of Carex.Therefore,the classification of Carex needs further discussion.Therefore,we have done the following research,in order to provide some new basis and help for the genus,species relationship and systematic classification of Carex.The results are as follows:1.Achenes micromorphologyAchenes are mostly oval,ellipse and triangular.The aspect ratio of achenes about is between 1.12-2.23.Most of the achenes of Carex are light or dark brown,and a few are brownish black,indicating that the appearance characteristics of the achenes are stable within the genus Carex.Scanning electron microscopy of the micromorphology of the achenes of 20 species can be divided into four types:(1)Reticulate-verrucous or papillary composite sculpture,which consists of a mesh ridge and a mesh.There is an oblate ridge or nipple in the center of the mesh.(2)verrucous or papillary sculpture,which consists of oblate ridges or papillae,and the size and shape of the protrusion vary with plant species.(3)Reticulate sculpture,which consists of a mesh ridge and a mesh.(4)Irregular sculpture,no netting and protrusions.There are some differences in the micromorphology of the achenes of Subgen.Vignea and Subgen.Carex;Carex sendaica,C.omeiensis and C.bodinieri.Liang Songyun was classified into Sect.Gracilis Tuckerm.in Flora of China(2009).In this study,sculpture of achenes are all Reticulate,the achenes are oval in shape,Apex rostrate,Base with short stalk,the colors are all light brown,and the stigma is 2.In view of the above characteristics,Flora of China is supported to be classified as Sect.Gracilis Tuckerm.However,due to the small amount of research material,it is only hoped to provide new research materials for the classification of Carex and provide evidence for systematic classification.2.Utricle epidermal micromorphologyThe micromorphology of the epidermis of the 25 plant utricles studied can be divided into two types: one is that there is no stomata in the outer skin of the utricles.Belonging to this type are: Carex sendaica,C.dimorpholepis,C.humilis,there is a stomata on the outer skin of the utricles.According to the shape of the outer epidermal cells and the shape of the vertical wall,it can be divided into two types:(1)the epidermis of the fruit capsule is nearly rectangular,and the vertical wall is shallow.Of this type are: Carex fulvorubescens subsp.longistipes,C.japonica,C.heterostachya,C.brunnea,C.middendorffii,C.ischnostachya,C.maackii,C.gibba,C.leiorhyncha,C.reptabunda,C.nubigena,C.eremopyroides,C.gotoi,C.hebecarpa,C.dichroa,C.doniana,C.duriuscula subsp.rigescens,C.maorshanica?(2)The epidermis of the utricles is nearly rectangular,and the vertical wall is deep and wavy.Belonging to this type are: Carex transversa,C.foraminata,C.omeiensis,C.ovatispiculata.The micromorphology of the epidermis of the inner and outer fruit capsules is the same as that of the Subgen.Carex Sect.Paludosae and Sect.Confertiflorae.It exhibits many common features;it belongs to the subgen.Vignea Sect.Foetidae.The group Sect.Phleoideae has a certain consistency,but it also has differences,so it can be used as a basis for classification.3 species of the same species belonging to Subgen.Carex Sect.Gracilis,Carex sendaica,C.omeiensis and C.brunnea has a large difference in characteristics,indicating that there is a certain degree of bias between the classification of plant species by only one classification method.The epidermal micromorphology of Carex has a certain consistency,but there are certain differences,so the epidermal micromorphology of the utricles can be used as the classification basis of the species;the epidermal micromorphology of the utricles has great similarity in some groups.Therefore,it can be used as a classification basis for the group;since the species of Carex are relatively rare in this paper,it is necessary to conduct further experimental research on the classification of the system.Therefore,this study aims to provide some new evidence for the classification of Carex.