菱属植物的幼苗形态及其系统学意义

本文对 10种菱属植物幼苗进行了形态学观察并探讨了其系统学意义 ,结果表明: ( 1)菱属植物的双苗是返祖现象 ; ( 2)菱沉水茎上的须根状物既不是沉水叶也不是托叶 ,而是不定根; ( 3)菱茎第 1节叶互生是返祖现象 ,而其余各节叶对生则是前进性畸形现象; ( 4)子叶柄、茎节间等长度性状可塑性很大且主要受环境 (水深 )影响 ,是对环境的适应. 而其粗度性状可塑性较小 ,可作为种类划分的参考依据;( 5)菱属的幼苗具有独特性 ,建议作为一个新的类型 —— 菱型 ( T ra pa Ty pe) .

The Seedling Morphology of Trapa and Its Systematic Significance.

In this paper,the seedling morphology of 10 species of Trapa and analysed their systematic significance are observed.These results are showed as follows:(1)The twin seedling of Trapa is an atavism;(2)The fibrous root like matter on node of submerged stem is adventitious root,neither submerged leaf nor stipule;(3)The alternate leaf on the first node is an atavism,but the opposite leaf on the rest node is an advanced deformity;(4)The length character such as cotyledon petiole,node length has large plasticity,which is mainly affected by environment (depth of water).While the thickness character has little plasticity,which maybe as one reference for dividing species;(5)It is suggested that Trapa maybe regard as a new seedling type Trapa Type owing to the specific characteristics of its seedling morphology.