带着闪闪发光水滴的泛生墙藓, 荷兰

© Arjan Troost/Minden Picture

放大镜下的墙藓

你可能会惊讶，这种点缀着水滴的优雅植物是一种苔藓：泛生墙藓，它更常见的名字是墙螺旋苔藓。泛生墙藓遍布全世界，甚至都市里也不乏它们的身影（都市里土壤干燥、空气污染严重，许多敏感的苔藓难以存活）。一般来说，苔藓是空气污染的精确监测器——它们吸收空气和水，所以污染物能够在它们的细胞中被检测出来。

泛生墙藓只是15000到25000种苔藓中的一种，这些古老的植物可以追溯到4.5亿年前。这种顽强的植物经受住了数亿年气候变化的考验，能够在冰冷的苔原或炙热的沙漠平原上生存。它们通过整个植物体来吸收水分。这种高效吸水的能力使苔藓成为第一批从森林火灾或极端高温中恢复过来的植物。广泛分布的苔藓还可以稳定土壤，使土壤保持水分。

这张照片正好捕捉到了雨滴落在苔藓上的瞬间。这是一个微距摄影的完美例子，当照相机把物体的实际尺寸放大很多倍时，我们更能欣赏到自然界的这种精致之美。

Wall-screw moss glistening with water droplets, Netherlands

© Arjan Troost/Minden Picture

Magnified moss. Tortula moss, Netherlands

You may be surprised to learn that this elegant plant dappled with water droplets is a variety of moss: Tortula muralis, better known as wall-screw moss. It's found all over the world, even in urban areas where more sensitive mosses have a hard time thriving because of dry soil and air pollution. Mosses in general are accurate monitors of air pollution—they absorb air and water, so contaminants can also be measured in their cells.

Wall-screw moss is just one of 15,000 to 25,000 species of moss, ancient plants that date back 450 million years. The hardy bunch …..