苔草属复序苔草亚属十四种植物叶片的解剖学研究

LEAF ANATOMY OF FOURTEEN SPECIES IN CAREX SUBGENUS INDOCAREX(CYPERACEAE)

选择中国复序苔草亚属６组４亚组的代表植物１４种，进行了叶片解剖学研究，观察了其横切面和表皮特征，证明上述特征在各类群之间存在差异，具有一定的系统学意义。这１４种植物叶片的横切面和表皮都具有一些原始的性状，表明复序苔草亚属中的植物可能在苔草属中是较原始的。在所观察的植物中，Ｓｅｃｔ．Ｐｏｌｙｓｔａｃｈｙａｅ植物叶片解剖学特征比较一致，说明此组的建立比较合理；而Ｓｅｃｔ．Ｉｎｄｉｃａ组已有明显分化，尤其是ＣａｒｅｘｓｃａｐｏｓａＣ．Ｂ．Ｃｌａｒｋｅ和Ｃ．ｄｅｎｓｉｆｉｍｂｒｉａｔａＴａｎｇｅｔＷａｎｇｅｘＳ．Ｙ．Ｌｉａｎｇ与其它植物明显不同，而且其外部形态特征在复序苔草亚属中也比较独特。

Among the subgenera of the genus Carex, the subgenus Indocarex has been seldom studied in any respects. Its systematic position and its subdivision are still disputable. Leaf anatomy of 14 species in the subgenus Indocarex from China was studied. The anatomical characters are proved to be systematically valuable. (1) Characters of lamina transverse section: All leaves of these 14 species are dorsiventral. The outline mostly V shaped, occasionally flat or nearly flat, with adaxial lateral rib in each half of lamina and some of them flanged. The cells of adaxial surface 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. The vascular bundles are collateral, bundle sheaths double layered, and the outer sheath parenchymatous and the inner sheath fibrous. (2) Characters of lamina epidermis: The shape of the cell on both surfaces is generally rectangular, and the anticlinal wall of epidermal cell sinuous; stomata is paracytic, elliptic to oblong, rarely sub circular; prickles occur on adaxial surfaces of certain species; papillae are only obvious on abaxial surface of C. moupinensis Franch. The characters of transverse section and epidermis of leaf blades of these 14 species differ from each other to certain degree, and closely related species are similar in anatomical characters. The anatomical characters of lamina are of value for classification at specific and sectional level of the subgenus Indocarex. Despite of the variation of these characters among species, a certain number of characters appears to be shared by the members of the subgenus, and some of the common characters are primitive. In addition, some gross morphological characters are common and primitive also. Therefore, the subgenus Indocarex may be primitive in the genus Carex. The anatomical and morphological characters of C. scaposa C. B. Clakre and C. densifimbriata Tang et Wang ex S. Y. Liang are distinct. The two species and their allies should be treated as section instead of subsection. The three species in the section Polystachyae share some anatomical characters and comprise a coherent group.