There's bacteria, there's algae..., vascular plants.

有细菌，有藻类，有维管植物。

Another type of seedless vascular plant is ferns, also known as monilophytes.

另一种无籽维管植物是蕨类植物，也被称为单生植物。

We're talking bryophytes and seedless vascular plants, the categories that include mosses and ferns, liverworts, and more.

我们说的是苔藓植物和无籽维管植物，这类植物包括苔藓、蕨类、苔类等。

As you can tell, bryophytes and seedless vascular plants are not simply low-to-the-ground lurkers.

正如你所知，苔藓植物和无籽维管植物并不是简单的地下潜伏者。

Although many of the early seedless vascular plants have gone extinct, you can still find some of them growing today.

虽然许多早期的无籽维管植物已经灭绝了，但你仍然可以发现它们中的一些在今天生长。

When Prototaxites first arrived on the scene, 420 million years ago, vascular plants had just begun to colonize the land.

4.2 亿年前，原紫杉首次出现时，维管束植物才刚刚开始在这片土地上定居。

Huge forests full of ferns, mosses, and some of the earliest vascular plants had taken over much of the planet.

长满蕨类植物、苔藓和一些最早的维管束植物的巨大森林占据了地球的大部分地区。

Well, the bryophytes and seedless vascular plants were some of the first plants to arise from that event — and many of them still exist today!

苔藓植物和无籽维管植物是第一批从那次事件中产生的植物，其中许多今天仍然存在！

But, they were the first plants to form true roots, stems, and leaves that contain vascular tissue, so they're considered the first vascular plants.

但是，它们是第一批形成真正的根、茎和含有维管组织的叶子的植物，所以它们被认为是第一批维管植物。

Next time, we'll be using these tools to uncover the history of plants, starting with bryophytes and seedless vascular plants, some of the earliest plants on Earth.

下节课，我们将用这些工具来揭开植物的历史，从苔藓植物和无籽维管植物开始，它们是地球上最早的植物。