I'm sorry to tell you this, but the experts are by no means in agreement on how the plant world -- all 300,000-odd species of them --should be divided up, and what the subdivisions should be called.

However, if you just need some kind of overview of the plant world for a  paper you're doing on "The Plant Kingdom,"  the outline shown below from a college textbook published way back in 1996 should serve your purposes well. I'll tell you why I'm using such an old system below, and notice that this system doesn't include algae. This system places algae into the Kingdom Protista.

If you walk into a typical backyard, possibly all the plants you'll see there -- all the grasses, weeds, garden plants, and all the leaf-bearing trees -- will belong to the last phylum, the Anthophyta, or the Flowering Plants. With regard to the flowering plants you may want to review our page on the differences between Monocots and Dicots.

Just keep in mind that nowadays when botanists are able to examine the actual genetic material of living things they are constantly getting new insights into how everything evolved, and what's related to what. They are making some amazing discoveries. It's a real revolution in thought -- very exciting! But for those of us just trying to get our heads organized about the basics, all these new ideas can be confusing. Therefore, the old system shown above does us the favor of providing a simple, general, somewhat accurate idea of how plants are related -- even though it's a bit outdated.

For a more updated idea of current ideas, look at our New Ideas about The Tree of Life page. Another place to see a chart reflecting some of the most recent ideas on how plants are related to one another is in the "green plant" section at the Tree of Life site. Not only is the subdividing at that site done in a drastically different manner from the Whittaker System, but also there are subdivision names that leave us scratching our heads, such as the Cladoxylopsida, Pertica varia and the Protopityales. Another site reviewing the Plant Kingdom in a rather broad, New-Agey way is the Palaeos.com site.

One way to get a handle on new concepts about the Plant Kingdom is to browse the above sites and when you see a new classification name that makes no sense, Google it. Keep this page available as you browse and use the Google search engine provided here:

Good luck!