phellem layer meaning in English

栓皮层

There are many adaptive changes in the two research subjects ( artemisia . songarica schrenk . and seriphidium . santolinum ( schrenk ) polijak . ) in morphology and anatomy , such as with the increase of the daily age , the root - shoots ratio increased ; the root became stronger ; the ratio of leaf volume and leaf area increased ; the volume of epidermic cell decreased ; the cut - icle and phellem layer on the surface of root thickened . stoma caved in leaf ; epidermal hair of leaf and stem well - developed , palisde tissue developed well , the cell gap decreased ; the spongy tissue disappeared ; leaf is kinds of isolateralthat is the typical xeromorphic structure ; crystal cell and fibric cell increased ; conducting tissue and mechanical tissue developed well ; bundle sheath appeared
实验研究的两种菊科（ compositae ）植物（准噶尔沙蒿（ artemisiasongaricaschrenk ）和沙漠绢蒿（ seriphidiumsantolinum ( schrenk ) poljak . ）），形态解剖方面的变化表现为：随日龄增加，根长/株高比值日益增大；根系逐渐发达；体积与叶面积比逐渐增大；表皮细胞体积变小；角质层增厚；根外部出现加厚的木栓层；气孔下陷；叶、茎部的表皮毛密布，栅栏组织日益发达；而细胞间隙日渐变小；海绵组织逐渐消失；叶面结构常为典型旱生结构? ?等叶面；晶细胞及纤维细胞数目增多；输导组织、机械组织日渐发达；具有维管束鞘等等。