Abstract:Vascular bundles of pedicel in flower of Orchidantha chinensis are scattered withinthe vascular region, but those just beneath the locule are arranged into an outer ringconsisted of large bundles and a central region with dispersed small bundles. The bundlesfrom the outer ring enter to the ovary wall and those from the central region extend to theaxis and become placental bundles which fade away gradually in prolongation. Thecarpellary dorsal bundles (cdbs), the accompanying bundles of the dorsals (abds) and theparietal bundles of the ovary wall could be easily distinguished. Three carpellary dorsalbundles finally enter the style and the stigma via prolongation. The abds, which are largebundles and each of which is adjacent to one carpel1ary dorsal bundle, separately extendinto the three stamens of the outer whorl of androecium. Two abaxial parietal bundles runupwards into the two stamens of inner whorl, while the adaxial one, accompanying theloss of the sixth stamen, enters the median of the labellum. The rest of bundles in ovarywa1l extend into prolongation and branch outwards in swelling part of the prolongation toform the outer ring of bundles, which finally run into three sepals and the remains incentral part arrange in a heart6haped ring. Abaxial bundles in convex end of heart6hapedring separate into two parts and enter to two lateral petals respectively, and the adaxialbundles in concave end of the ring firstly arrange in two rows with the large bundles inouter row and the small ones in inner row but finally become one row and along with theadaxial parietal bundle enter into labellum. It is worth to point out that this kind oflabellum, which is not only a member of corolla but also contains the bundle of the sixthlost stamen, is distinctly different from the cucullatum of Marantaceae and the labeIla inCannaceae, Zingiberaceae and Costaceae, which are only derived fr0m stadrinodes. Basingon the comparison of the origin and structure of the vascular system in androecium ofZingiberales, except Strelitziaceae- because no information could be found in this family,the authors make a prelidrinary suggestion that among the seven fadrilies of Zingiberales,Lowiaceae dright be more close to Musaceae.
