Science 5: Inside Plant Stems

to talk about all the other hard-working people who made the movie happen behind the scenes. [Camera crew looking unhappy]

Or maybe we'll hear a new song on the radio and remark how that singer did a really

great job – even though it was someone else who actually wrote the song in the first place! [Songwriter is kicked off stage]

And there's another example of this that exists in nature – and you're probably guilty of it, too.

When you're walking down the street and spot a beautiful garden, you might stop and say, [Boy walking through a garden]

“Wow! That flower sure is pretty!”

But what about the hard-working stem supporting that beautiful flower? It deserves some credit

too, y'know. These hard-working plant stems aren't always

the same, and actually come in a variety of types. [Different flowers are shown]

Herbaceous stems, for instance, are fleshy on the inside.

And no, we don't mean some sort of horror movie where the stems are half plant, [People running away from a half plant man]

half man…though that does sound really creepy…

Think more along the lines of a daisy. If you've ever made a daisy chain, then you know

what fleshy, herbaceous stem feels like. Woody stems, on the other hand, are what we

might call twigs, because they look and feel, well, woody. [Woody from Toy Story appears]

And no, they don't say, "There's a snake in my boot!" We were disappointed, too.

And Tuberous stems, meanwhile, generally support bulb plants, like tulips.

But regardless of how they look and feel, all stems share the same purpose: think of

them like a highway, but instead of transporting cars and trucks, they transport water, nutrients [Diagram of the stem showing flow]

and the products of photosynthesis throughout the plant.

And bonus: there aren't any sneaky cops waiting to give out speeding tickets. [Cop appears inside the plant stem]

Stems are typically divided into several main parts...

The pith, a spongy material used to store and transport nutrients...

The xylem, a network of tubes used to transport water and nutrients...

The phloem, a network of tubes used to transport food throughout the plant... [Coop and Dino showing definitions of the different components]

The cambium and cork, both of which are tissues used to help the stem continue to grow...

And the epidermis, which is the plant's skin.

But again, not in a creepy horror movie way... Depending on the sort of stem you have, these

different parts of the plant might be arranged differently, but the general idea is always

the same: to protect the plant, keep it growing, and feed it all the food and water it needs! [The stem relaxing on a chair]

Phew. Sounds like a tough job…we hope there's some sort of National Stem's Day... [The stem bringing the flower a drink]

we'll pitch it to Hallmark.

So the next time you stop and smell the roses, give a bit of a love to the stem below

doing all the hard work.

But don't actually physically give it any love, because we don't want to imagine what

would happen if you tried to smooch one of those thorny stems. Not pretty. [Beware of thorns sign appears]