How can you tell if a plant is poisonous?

– Hi, Doug. – Hi, Landon. – I have a question for you. How can you tell if a plant is poisonous?- That’s a great question. There’s probably lots of food from plantsthat you love to eat. Maybe you like strawberries
or carrots or raspberries. I’m guessing most of these are thingsyou get from the grocery store. All of the foods from
plants in the grocery storegrow in the wild, too, but
definitely not all of the plantsyou can find in the wild are safe to eat. You might have heard that
some plants out thereare really poisonous. Here’s a great example.
It’s called the manchineel. This plant is considered to beone of the world’s most dangerous trees. If you barely touch it
or even stand under itto keep dry from the rain,
the sap from this treecan burn your hands and
give you huge blisters. Even using its wood in
a campfire isn’t safebecause the smoke can make you go blind. In the country of England,some people have put together a collectionof some of the most poisonous
plants in the world. It’s called The Poison Garden. You can visit there, but be carefulnot to touch or smell any of the flowers. That’s because they’re all poisonous. So poisonous that some
visitors have actually fainted. They didn’t follow the no
smelling, no touching rules. Seriously. Now these are
really extreme examples. To be honest, there’s probably
nothing that poisonousnear where you live. Still, there might be
some poisonous plants. Do you know of any plants near
you that might be poisonous?Now would be a good time to
pause the video and discuss. Okay, you ready?Here’s one you might have thought of. This plant called poison ivy,or maybe this one called poison oak. If you accidentally touch the leavesof either of these plants,you’ll probably get a terribly itchy rash. That’s because each of these plantsare covered in a poisonous
oil that they make. Now, after thinking about
all of these poisonousor dangerous plants, it could be temptingto think that all plants growing
in the wild are dangerous,that it would be best to just
stay super far away from them,but nothing could be
further from the truth. The world is full of incredible,
safe and delicious plants,plants in the wild that we can eat. Like these kids are picking berriesin the country of Sweden. The forests in Sweden are
full of amazing berrieswith names like cloudberries,
lingonberries and blueberries,and Sweden takes its
berry picking so seriouslythere’s even a law in Sweden
that lets you pick berrieswherever you want, even if
it’s on someone else’s land. But, what if you accidentally
pick a poisonous berryand you got sick?That’s why this question is so important. How can you tell if a plant is poisonous?When it comes to plants like
poison ivy or poison oak,you may have heard this rule:
“Leaves of three, let it be. “If you haven’t, that’s
a good rule to know. The first part of that rule,
the leaves of three part,is actually telling you to
notice a pattern in the leaves. You see, poison ivy and poison oak leavesboth grow in patterns of three. Look closely. See how there are three leavescoming out of the same stem?So, by learning this pattern,you can know to stay away from them. Learning patterns doesn’t just helpwith the poisonous plants either. It’s what also helps you figure outwhich plants you can eat. Like check out this plant. If you’ve ever eaten a candy
cane or tasted mint gum,you already know what
this plant tastes like. It’s called a peppermint plant,and it’s where we get the flavoringfor a lot of mint-flavored things. Do you notice the stem?It’s got a square shape,not a round shape like most other plants. That’s because peppermint
is part of the mint family,and almost all of the
members of the mint familyhave square-shaped stems. The cool thing about
plants in the mint family,plants like peppermint, basil and oregano,is that almost none of them are poisonous. So knowing this pattern
about the square-shape stemscan help you tell which
plants are safe to eat. But the problem is no
one pattern is perfect. For example, if you only follow
the leaves of three patternto stay away from poison
ivy, you’re going to miss outon some awesome fruits, like
strawberries and raspberries. They also have three leaves on each stem. Ah, so if no one pattern is perfect,how do you get really goodat knowing which plants are poisonous?Well, there’s only one way. You just learn more and
more patterns to look for. Take a look at this raspberry plant. It can have the same three-leaf patternthat poison ivy and poison oak have,but knowing more patterns can
help you tell the difference. See how the raspberry plant
has tiny thorns on its stem?A poison ivy plant will
never have a thorny stem. Also, notice how the raspberry
leaves are more sharpand pointy around the edges. A poison ivy leaf is smoother
and more rounded looking. So, in summary, you can learn
to tell poisonous plantsfrom non-poisonous ones by
learning different patterns. No one pattern can tell youwhether a plant is poisonous or not. You’ll want to learn lots of patterns,but you can do that by getting
the help of a plant expertwho can teach you. Chances are there are local
groups of experts in your areawho go looking for wild
plants they can eat,called foraging groups,where you can get to meet
some of these plant expertsand start learning the patterns. There’s also some great books on thisyou can buy or check out from the library. That’s all for this week’s question. Thanks, Landon, for asking it. There are mysteries all around us. Stay curious and see you next week.