Study On Leaf Epidermis Micro-morphology Of Carex (Cyperaceae) In Shandong Province

Carex L. is the largest genera in Cyperaceae. More than 2000 species were recorded all over the world, and most of them were found in North America and East Asia that belonged to the northern temperate zone. More than 500 species were recorded all over the country in China. Carex L. was one of the main big generas in Chinese floristic composition. It has always been considered by scholars from home and abroad that it is very difficult to be classified, because its categories are massive, its biological properties are complex, and its characters are widely changes.In this paper, leaf epidermis micro-morphological characteristics of 27 species, one subspecies and two varieties belonging to Carex in Shandong province were studied with optical microscope. The results showed that there was no short cell but long cells between vein zones. The long cells were long-tubular, short-tubular, and sub-tetragonal, and their edges were sub-straight, sinuolate, sinuous, and sinuate. Their subsidiary cells on the stomas were triangular, dome-shaped to triangular, dome-shaped, low dome-shaped and sub-parallel-sided. Prickle-hairs were widely existed in epicuticles between the vein zones. And some were existed in lower epidermis vein in only several individual species. According to prickle-hairs exist or absent in vein zone, prickle-hair type, none- prickle-hair type, and 5 subtypes were divided.There was high consistence in the 6 groups in leaf epidermis micro-morphological characteristics such as Sect. Paludosae Fries, Sect. Mitratae Kükenth, Sect. Digitatae Fries, Sect.Siderostictae Franch., Sect.Forficulae Franch., and Sect. Praelongae (Kükenth) Nelmes. It indicated that leaf epidermis micro-morphological characteristic was used to classify Carex L had certain significance.C. heterostachya Bge. in external feature was very similar to C. maximowiczii Miq. and C. dimorpholepis Steud.. There also was high consistence in leaf epidermis micro-morphological characteristics. All of them had many mastoids in lower epidermis between vein zones. But C. heterostachya Bge.was distinct from C. gotoi Ohwi, C. tangiana Ohwi, C. scabrifolia Steud. And C. pumila Thunb. although they were the same group. So it was more reasonable to classify C.heterostachya Bge. to Sect.Praelongae ( Kükenth) Nelmes than any other groups.C. lanceolata var. subpediformis Kükenth., as a variety of C. lanceolata Boott., had little differences with C. lanceolata Boott.. so it was supported to be a variety.C. siderosticta var. pilosa Lèvl. Ex Nakai, as a variety of C. siderosticta Hance, was distinct from C. siderosticta Hance in external feature and leaf epidermis micro-morphological characteristics. So it was suggested to classify C. siderosticta var. pilosa Levl. Ex Nakai to species : Care pilosa (Lèvl. Ex Nakai) F. Z. Li & X. Z. Ding com. nov.Leaf epidermis micro-morphological characteristics laid high consistence in Carex. It indicated that Carex was a natural group. But there were some differences in interspecies and intergroups, and it could provide reference for classifying species and groups. But considering the materials are deficiency, if leaf epidermis micro-morphological characteristics could be used to classify subgenus, it could not be concluded. And it needs further research.