A primary vein, also known as the midrib, is the main vascular structure running through the center of a leaf. [1] . The primary vein is crucial for the leaf’s efficiency in photosynthesis and …

比较粗大的叶脉称为粗脉（major vein），比较细小的叶脉称为细脉（minor vein），细脉的末端极细，是由1-2根假导管构成，任何植物到一定程度以下的细脉则不形成维管束鞘。 如在网状脉 …

2017年9月6日 · The high hexose and amide concentrations found in the midvein compared with laminae suggest different senescence programmes, and an important role for the veins in the …

位于叶片中央大而明显的脉，称为 中脉 或主脉（midvein）。 由中脉两侧第一次分出的许多较细的脉，称为侧脉（lateral veins）。 自侧脉发出的、比侧脉更细小的脉，称为小脉或 细脉 …

The margin is the edge of the leaf and its morphology can be useful for identification. This leaf margin could be described as serrate, much like a serrated knife. In the center of the leaf, a …

In angiosperm: Leaves …to form the midvein, or midrib. The smaller lateral veins of the leaf are initiated near the leaf tip; subsequent major lateral veins are initiated sequentially toward the …

英文: The origin of the midvein calli developed mainly from the vascular cylinder, the palisade tissues and the phloem parenchyma cells. 中文: 主脉的愈伤组织主要由维管束鞘薄壁细胞,以及 …

The midvein elongates acropetally toward the leaf tip. Only after the commencement of acropetal growth does the midvein also commence development toward the stem vascular strand, …

位于叶片中央大而明显的脉，称为中脉或主脉（midvein）。 由中脉两侧第一次分出的许多较细的脉，称为侧脉（lateral veins）。 自侧脉发出的、比侧脉更细小的脉，称为小脉或细脉（minor …

Midvein（中脈）是指植物葉片或某些特定結構中的主脈，通常為其主要的血管，負責支撐葉片並運送水分和養分。 中脈通常在葉片的中心位置延伸，並且常常是葉片其他細小脈絡的起點。