木犀属植物叶柄的比较解剖学研究

对木犀属(Osmanthus)26种植物叶柄的解剖结构进行了研究.结果表明,木犀属植物叶柄的解剖特征存在比较丰富的变异,叶柄横切面形状有3种类型(U型、V型、Y型),周缘波状、浅波状或近平滑;表皮毛有或无;维管束一般为1大2小,维管束轮廓在种问变异丰富,维管束类型有周韧、近周韧、外韧3种;小叶月桂、牛矢果、厚边木犀、美洲木犀叶柄中央具髓腔,部分种叶柄有硬化细胞或石细胞存在.木犀属植物叶柄的解剖结构特征比较稳定,可作为该属的分种特征.

Comparative Anatomical Studies on Petioles of Osmanthus

Petiolar structure of 26 Osmanthus species was observed under light microscope. The results showed that there were rich variations among petiolar anatomical characters of Osmanthus. There are 3 types of cross section of petioles (U, V and Y types), the outmargin shapes of petioles are undulated, sinuolate or nearly smooth. Trichomes are present or not. In most species, there are 3 vascular bundles (one bigger and two smaller) in cross section of petioles. There are abundant variations on outline of vascular bundle among species. The vascular bundle types in cross section of petioles are amphicribral bundle, almost amphicribral bundle and collateral bundle. There is a pith cavity on center of vascular bundle in O. minor, O. matsumuranus, O. marginatus and O. americanus. Some species have sclerotic cell or stone cell. The anatomical characters of petioles could be used to circumscribe the species within Osmanthus as they are stable between different species.