四川当归属8种植物果实和叶柄解剖学研究

Anatomical Studies on Fruits and Petioles of 8 Species of Angelica L.from Sichuan Province

通过对四川当归属植物果实的解剖研究表明,果实均背腹压扁,背棱槽油管多为1,合生面油管多为2,在少数种间有一定差异,如茂汶当归和紫花前胡合生面多于2;侧棱翅状,较果体宽,或与果体近等宽,也有的窄于果体;胚乳腹面微凹或平直,偶有凸出。果实的油管特征、侧棱翅发达程度和胚乳的形状等特征可以为种间关系提供参考。叶柄类型多样,包括圆环型、“Φ”型、星散型等。叶柄横切面的形状、近轴面沟槽的有无、髓腔的有无以及叶柄横切面上维管束的数目和排列类型等特征比较稳定,并且具有明显的种间差异,可以作为本属分类的重要依据。

Sichuan is one of the two rich centers of Angelica L. in China, which is also one of the two distribution centers in the world. Fruits and petioles of 8 species of Angelica L. from Sichuan Province were dissected and observed with microscope. Studies on fruit anatomy of 8 species show that all of them are dorsal compressed, in most cases the valleculae of dorsal rib each has only one vitta and most concrescence may see two vittae, excluding some special species such as A. rnaowenensis and A. decursiva which have more than two vittae in their concrescences; Their aliform lateral rib may equal to or wider than the fruit itself but in some cases narrower; upper sides of endosperm are usually flat or slightly sunk and occasionally raise, while some are convex. These above-mentioned three characteristics of fruits, number of vitta, evolvement status of lateral rib and endosperm form, may serve as reference in interspecies relationship study. The anatomical characteristics of petioles are very diverse, include ring form, “Φ”-form and atactostele form. Such characteristics as figures of transverse section, the presence and shape of the groove on the adaxial side, smooth or undulate margin, the presence and shape of pith cavity, the number of vascular bundle and its pattern of distribution can be used as useful taxonomical evidences, for the stability and apparent diversity between different species.