Taxonomic Revision Of Carex Sect. Careyanae (Cyperaceae) In Eastern Asia, With The Emphasis On The Relation With Sect. Rhomboidales

The Cyperaceae which includes more than 100 genra, comprises 4500-5000 species is a large family in Monocotyledoneae distributed wordwide. There are 28 genera and 500 species in China. Carex which has at least 2000 species over the world is a large genus in Cyperaceae. Although a lot of work has been doing about the classification of subgenera, none of uniform criterion is agreed by almost researchers. The relation of Sect. Careyanae and Sect. Rhomboidales is always one of the most difficult problems.Based on literature, extensive field work and herbarium examination, the morphological characters, which were used for taxonomy by the previous taxonomists, were evaluated.23 samples (containing 20 taxa) were used for leaf anamony and 23 achene samples (containing 19 taxa) were used for SEM observation. As a result, a taxonomic revision of Sect. Careyanae is made to clarify species delimitation. Main results in our study are summarized as follows:1. Characters of leaf anatomy23 samples were observed from 20 taxa, of which,8 species from China,6 species and 4 varieties from Japan,1 species and 1 variety from Korea. Characters of transverse section:The outline mostly flat occasionally lightly V-shaped or V-shaped. The cells of adaxial surface were larger than those of abaxial surface, and the epidermal cells over veins usually smaller than others. Air-cavities between vascular bundles are well developed and bulliform cells also well developed in most taxa. There is sclerenchyma around veins in different degree. The one epidermal appendage is epidermal hair, the other is tubercule. The layer of bundle sheaths was mostly one, occasionally two. From the observations on different samples of C. tremula (containing 2 samples), C. taihokuensis (containing 2 samples), C. tatsutakensis (containing 2 samples) leaf anatomical character were consistent. There was a difference in outline and the differentiation of mesophyll cell between C. giraldiana, C. longerostrata, C. pseudo-longerostrata and other species, showed that the former were closed to Sect. Rhomboidales.2. Micromorphology of leaf epidermisFifteen species and five varieties (totally twenty three samples) were obtained. The shape of epidermic cells were generally rectangular, the anticlinal walls were mostly sinuate, stomata almost distributed under the abaxial epidermis, and sometimes siliceous papillae were obvious on epidermis, epidermic appendages could be divided into two types, viz. prickle and trichome. Characters of leaf epidermic between samples from different place had no significant difference. According to the characters, it showed that C. longerostrata, C. blini and C. pseudo-longerostrata should be placed in Sect. Rhomboidales. The characters of C. macrandrolepis and C. tatsutakensis were different with other members of Sect. Careyanae.3. Achene micromorphologyFourteen species and five varieties (totally twenty three samples) were observed under SEM. Shape and Size of achene were stable among different samples of the same species. Mostly achene had straight short stipitate at base and straight beak. Only C. macrandrolepis and C. tatsutakensis no beak became special species. It showed that C. macrandrolepis and C. tatsutakensis should not placed in Sect. Careyanae. While epidermal layer of achene had one or two primary silicon bodies in each cell in mostly memberers which belong to Sect. Careyanae C. longerostrata and C. pseudolongerostrata had no primary silicon. This characters was closed to Sect. Rhomboidales member's.4. Taxonomic revisionA taxonomic revision of Sect. Careyanae in Eastern Asia is made in this work, with twenty species in the world, ten species and six varieties in China. According to morphological characters and micromorphological features C. longerostrata,C. pseudolongerostrata and C. giraldiana should be placed in Sect. Rhomboidales. C. vanoitii was not suitable to become one species but a variant of C. parciflora. C. filipes var. tremula ought to be merged in to C. flipes. C. zhejiangensis was described as new.