This is one of the best houseplants out there.
这是最好养的室内植物之一。
Forget to water it for a week or two. And it'll be fine.
一两个星期都不需要浇水，没有任何问题。
Not because it doesn't need water.
不是因为它不需要水。
But because as long as there's enough humidity around, it can grab water out of thin air.
而是因为，只要环境中有足够的水汽，它就可以从稀薄的空气中吸取水分。
A power this plant has because of where it would live if it weren't on your windowsill.
这是这种植物特有的能力，取决于其生长环境的特殊，毕竟，这种植物不是突然就出现在你的窗台上的。
Since
the forest floor can be a dark and sometimes crowded place, some plants
have evolved to grow on prime unused real estate. ON other plants.
森林有其黑暗生存法则，很拥挤，所以一些植物已经进化出在特殊的地方求生存的能力了，也就是在其他植物上。
But living far from the soil creates challenges, like how to get water.
但不在土壤扎根也会有一些问题，比如如何获取水分。
So,
plants-on-plants, which scientists call epiphytes, have evolved lots of
ways to grab and store different types of moisture they do have access
to,
科学家发现，有一种寄生植物，在进化的过程中，发展出许多方法来获取和存储它们可以获得的不同类型的水分，
like falling rain, the streams that trickle down a tree's bark, even fog suspended in the air around them.
就像下雨，顺着树皮流下来的水滴，甚至是悬浮在空气中的水雾。
Our favorite houseplant, for instance, is covered with microscopic hairs that trap airborne water vapor.
例如，我们最喜欢的室内植物长满了能捕获空气中水蒸气的微小毛发。
Other plants-on-plants, like bromeliads, funnel water into specialized storage tanks.
其他植物上的植物，如菠萝，会将水分输送到专门的存储处。
And epiphytic mosses have super-flexible cell walls to help them suck up water around them.
附生苔藓有超柔软的细胞壁，可以帮助它们吸收周围的水分。
Some can absorb as much as 7000% of their dry weight.
有些可以吸收的水分差不多相当于自身重量的7000%。
For comparison, a good kitchen sponge can only absorb a tiny fraction of that.
相比之下，再上乘的厨房海绵能吸收的水也不足为道了。
Plants-on-plants' awesome water-grabbing and storing abilities enable them to exist in all sorts of forests all over Earth.
寄生植物令人惊叹的吸水和储存能力使它们能够在地球上的各种森林中生存。
And in the process, epiphytes make more water available to the forests as a whole.
在这个过程中，寄生植物为整个森林提供了更多的水分。
See, water generally leaves forests via two pathways.
水离开森林的路径有两条。
By hitting already-wet soil and running into local waterways, and eventually out to the ocean.
通过潮湿的土壤，进入附近的河流等水道中，并最终流入海洋。
Or
by going airborne, either after evaporating off a forest's surfaces or
getting basically breathed out as plants photosynthesize.
或者，在表面蒸发，或者在植物光合作用的过程中被呼出，然后通过空气传播。
Plants-on-plants limit both these kinds of water loss.
寄生植物这两种水分的流失都很少。
First, because even though epiphytes only make up a small percentage of the vegetation in a forest,
第一，寄生植物只占森林植被的一小部分，
their water-grabbing abilities help them intercept as much as 15% of the rain that falls.
所以它们的吸水能力可以帮其拦截高达15%的降雨。
So
instead of hitting the ground and flowing out of a forest, water stays
there, providing habitat and hydration for all sorts of life.
因此，水不会落在地上，也不会从森林流出，而是留在那里，为各种生命提供栖息地和水分。
Second, by hanging out on exposed trunks and branches, plants-on-plants can help shade forests and buffer them from wind,
其次，因为挂在裸露的树干和树枝上，这些寄生植物可以为森林遮荫，并为其抵御风，
which means less water disappears into the sky.
也就是说，通过空气流失的水分会变得更少。
Epiphytes
can reduce evaporation off a forest's surfaces by 20%, and can reduce
water loss through its leaves by as much as half.
寄生植物可以将森林表面的水汽蒸发量减少20%，并可以将通过树叶流失的水分减少一半。
Plus, they can intercept some of the water that does go airborne and slurp it up themselves.
此外，它们还可以拦截一些已经进入空气中的水分，将其储存在自己体内。
By
keeping water cycling through the forest, rather than leaving it,
plants on plants can make it possible for super-thirsty types of plants
to grow,
这样就可以让水分在森林中循环，而不会离开森林，所以寄生植物在极干旱的环境下也能生存，
and can help forests thrive even during dry spells.
即使在干旱时期也能使森林绿意盎然。
What's more, concentrated moisture can supercharge clouds above forests.
更重要的是，浓缩的湿气会给森林上空的云层带来额外的推力。
In
other words, plants-on-plants can help make it rain, which is weird for
plants that can survive without getting watered in the first place.
换句话说，这种植物可以帮助降雨，联想到它们不用浇水就能存活这个特点，这一点真的还让人挺诧异的。