管花肉苁蓉茎异常结构的发育解剖学研究

管花肉苁蓉茎内存在类似于单子叶植物的散生初生维管束。它由散生在基本分生组织中的原形成层束分化而成。在原形成层来分化的过程中，每个原形成层束可通过分离形成2—7个初生维管束，使初生维管束的数目迅速增加。当初生维管束开始正常次生生长时，正常维管束韧皮部外方的薄壁组织细胞或远离维管柬的薄壁组织细胞转变为异常形成层束。异常次生维管束与正常维管束以韧皮部相对或韧皮部并列的方式排列，或异常次生维管束单个存在于薄壁组织中。

DEVELOPMENTAL ANATOMY STUDIES ON THE ANOMALOUS STRUCTURE IN THE STEM OF CISTANCHE TUBULOSA

The stem of Cistanche tubulosa (Schrenk) R. Wight. is similar tomonocotylous plantin the scattered bundles. Primary vascular bundles ouiginate from procambial strandswhich are scattered in ground meristem. In the process of differentiation of procambialstrands,each procambial strand can form 2-- 7 independent primary vascular bundles byseparating and the number of primary vascular bundles is on the increase. When primaryvascular bundles begin their normal secondary growth,the parenchyma cells outside thephoem of each bundle or at a distance from vascular bundles turn into anomaleuscambium bundles. Anomalous secondary vascular and nomal vascular bundle are arranged withtheir phoems face to face or side by side,and single anomalous secondary bundle canexist in the ground tissue too.