大鹤望兰花部维管束系统的解剖学研究

Studies on Vascular System Anatomy of Strelitzia nicolai Flower

大鹤望兰花梗横切面近三角形 ,花梗的维管束分散分布在基本组织内。室下区的维管束大致排列成两部分 ,外方为一到两环维管束组成的外维管束环 ,中央为分散排列的中央维管束区。前者的维管束进入子房壁 ,后者的维管束进入子房的中轴 ,形成胎座维管束。至延长部后 ,胎座维管束逐渐消失。子房壁上的维管束较易识别的有心皮背束、心皮背束伴束和隔膜束。 3束心皮背束经延长部最终进入花柱。 3枚心皮背束伴束最终分别进入一枚外轮雄蕊。 3枚隔膜束中远轴面的两束各进入一枚内轮雄蕊 ,而近轴面的一枚于延长部中上部产生分支 ,其中内方的分支逐渐远离近轴面向中央靠近 ,至延长部顶部于远轴面萼片及花柱刚形成时消失 ;外方的分支与近轴面另外 4束维管束排成一行 ,最后一同进入中央花瓣。子房壁其余的维管束进入延长部后逐渐分成 5个主要部分 ,其中近轴面两侧角部和远轴面的角部 3部分进入萼片 ,两侧边部的维管束进入两侧生花辨。中央花瓣含有近轴面隔膜束 1个分支。

The outline of transverse section of the pedicel is more or less triangular in Strelitzia nicolai Regel & Koern. Vascular bundles of pedicel are scattered within the fundamental tissue, but those just beneath the locule region are arranged into an outer region consisted of two-ring bundles and a central region with dispersed small bundles. The bundles from the outer region enter the ovary wall, while those from the central region extend into the axile and become placental bundles which fade away gradually in prolongation. The carpellary dorsal bundles (cdbs), the accompanying bundles of the dorsals(abds) and the parietal bundles of ovary wall could be easily distinguished. Three cdbs finally enter the style via prolongation. The abds separately extend into three stamens of the outer whorl of androecium. Two abaxial parietal bundles run upwards into the two stamens of inner whorl, while the adaxial one divide into two branches. The inner one of these branches is gradually separated from the outer one and moves towards the central axile, and finally fades away just when the style appears. The outer one is arranged in a line with the other four bundles which finally enters the median petal. The other bundles of the ovary wall are arranged as five parts after extending into prolongation, of which those within the three corners enter the sepal respectively, and those on the lateral enter two lateral petals. As a result,the median petal contains an outer branch of the adaxial parietal bundle. In addition, comparison of the origin of vascular system in androecium of Zingiberales and its systematic significance are discussed.