Using the paraffin section method, the transection anatomical characters of mericarps of six species including Pleurospermum benthamii (Wall. ex DC.) Clarke and P. franchetianum Hemsl., P. hookeri Clarke var. thomsonii Clarke and P. giraldii Diels, P. prattii Wolff and P. wrightianum de Boiss. of Pleurospermum Hoffm. in Apiaceae were observed in detail and analyzed comparatively. The results show that although the external morphological characters of every two species in six species are similar, but the anatomical structures of mericarps were different. The common features of them are relatively developed ribs, separation of exocarp and mesocarp, with a cavity and one obvious vascular bundle in each rib, highly reductive mesocarp, thin mericarp wall, with vittae in vallecular and commissure, vitta number of commissure one time more than that of vallecular. The different features include the shape of mericarp transection, compressed degree of mericarp body, development degree of rib, arching degree of exocarp, with or without corneous layer and its thickness, size and position of vascular bundle, vitta number in vallecular and the relationship between commissure and lateral ribs. According to these observation results, it is suggested that the combination of P. prattii and P. wrightianum seems inappropriate, whereas the merger of P. hookeri var. thomsonii and P. giraldii should be proposed.%采用石蜡切片法对伞形科(Apiaceae)棱子芹属(Pleurospermum Hoffm.)的宝兴棱子芹[P.benthamii(Wall.ex DC.)Clarke]和松潘棱子芹(P.franchetianum Hemsl.)、西藏棱子芹(P.hookeri Clarke var.thomsonii Clarke)和太白棱子芹(P.raldii Diels)、康定棱子芹(P.prattii Wolff)和瘤果棱子芹(P.wrightianum de Boiss.)的果实横切面的解剖结构特征进行了详细观察和比较分析.结果表明:6种植物虽然在外部形态上两两相似,但彼此间的果实解剖结构特征却存在一定的差异.共同特征是果棱均比较发达,且外果皮与中果皮分离,常形成空腔,每个果棱有1个明显的维管束,中果皮高度退化,果壁均很薄,棱槽和合生面均有油管,其中合生面油管数为棱槽油管数的2倍;差异主要表现在果实横切面外形、果体的压扁程度、果棱的发达程度、外果皮拱起程度及角质层的有无和厚度、维管束大小和着生位置、棱槽油管数以及合生面与侧棱的关系等方面.根据观察结果认为康定棱子芹与瘤果棱子芹不宜合并,建议将西藏棱子芹与太白棱子芹予以合并.
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