acrogens

n.any flowerless plant such as a fern (pteridophyte) or moss (bryophyte) in which growth occurs only at the tip of the main stem

1. Ferns are examples of acrogens, as they grow from the tips.
   蕨类植物是顶端生长植物的例子，因为它们从顶端生长。
2. In botanical studies, acrogens are contrasted with other groups like thallophytes.
   在植物学研究中，顶端生长植物与藻类等其他群体形成对比。