At the upper timberline the trees begin to become twisted and deformed.

行界，和雪一样，在热最高，在极地最低。从极地地区海平面到干燥亚热地区海拔4 500米处以及潮湿热地区海拔3 500米至4 500米处都有行界。界内通常是常绿，它们和处于行界处极端恶劣环境中生叶木相比，具有一定优势。然而，在部分地区也有由叶阔叶林组成界。例如，在喜马拉雅部分地区，桦就在界。

It is called an ever-green tree; for as long as one old brown leaf drops off, a fresh green one grows in its place.

冬青是一种" 常绿" ，因为只要冬青一片叶子变成了棕色，了下来，在原来地方，就会出一片新绿叶！

Annual and perennial plants, deciduous and evergreen trees, plants inhabiting different stations and fitted for extremely different climates, can often be crossed with ease.

一年生和多年生植物、 叶和常绿、栖息在不同地点并适应截然不同气候植物通常可以轻松杂交。

On the other end of the spectrum are plants that don't shed their leaves — for example, the pines, spruces, cedars and firs that make up the conifers, or evergreens.

不会叶植物包括松、云杉、雪松和冷杉等针叶或常绿。

This continent is dominated by a single family, Eucalyptus, which is evergreen, regardless of the substantial climatic variations found there, and leads to forests unlike any other in character.

这片大陆主要盛产桉科，无论那里气候变化如何，桉始终是常绿，并且形成了与其他森林不同特征。