Poaceae

Poaceae is a big family. There are more than 10,000 species of grass and they pop up on nearly every continent.

Grasses have a odd way of growing. They telescope like an old antenna, growing up from the base rather than from the tip. It's a matter of survival. A lot of animals graze on grass, eating from the top down. If grasses depended on growing from the tip up, cows, elk and such would kill them with every bite. And probably did. But the grasses surviving today today evolved and saved themselves.

Grass culms are hollow. They grow as sheaths from inside the section below. Each sheath grows to a certain length, then diverges at an angle to form a leaf. The next shealth grows up from inside the previous one, producing another leaf. Eventually, the final section grows and, instead of a leaf, grows an inflorescence.

There are two big groups of grasses: cold season and warm season.