Leaf anatomy of nine species in Carex sect.Rhomboidales(Cyperaceae)

Leaf anatomy of nine species in Carex sect.Rhomboidales(Cyperaceae) from China was studied by the method of paraffin section.These nine species shared some common characters as follows: 1) The outline of leaf transverse section was V-shaped or almost V-shaped and the air-cavities between vascular bundles were well developed;2) The bulliform cells on the midrib were also well developed,and midrib vascular bundles were surrounded with sclerenchyma;3) The adaxial epidermal cells were larger than those of abaxial surface,and the mesophyll cells all appeared different degree of differentiation;4) Both adaxial and abaxial epidermal cells were oblong and their anticlinal walls were deeply undulate,and the epidermal appendage was prickle.However,there were also some diagnostic characters among the species,viz.the layer of bulliform cells,the layer of the mesophyll cells,the developed condition of the sclerenchyma,the distribution pattern of stoma on abaxial epidermis,the stomatal density,and stomatal index etc.A key based upon the leaf anatomical characters to the nine species was provided as well.