Evolution of strawberries and peanuts

Where do strawberries fit in relation to other plants? They seem to be fairly typical angiosperms, but produce fruit with seeds on the outside. Do any other plants do this? How did this phenomenon evolve? How does it aid in seed dispersal? Also, is the term “berry” biologically meaningful, and if so, what makes a fruit a berry?

How did peanuts evolve to grow fruit underground? I assume the plant produces flowers above ground and then somehow moves the developing fruit underground. Do other plants do this? How does it aid seed dispersal? How common are peanuts with three seeds? Do four seeds ever grow in a shell?

I don’t know about the rest of it, but berry is definitely a botanical term. A berry is a fruit derived from a single fertilized ovary, like a grape, or maybe a blueberry. A raspberry, IIRC (not having touched this since AP Biology in tenth grade,which was a good while ago), is a whole bunch of little berries pressed together, or an aggregate berry - think of each little bead of a raspberry, containing a single seed, as one berry. I believe that a strawberry is a member of a different subcategory of berry types, defined by the fact that you can’t really separate out the different little miniberries made by each different fertilized ovary because they’ve all fused so completely, but I can’t remember what that’s called.

Strawberries aren’t a berry but an accessory friut, a bunch of small fruit segments that are so close to each other that they fuse during development. Other accessory fruits include raspberry and blackberry (of which neither are berries). Several plants present their seeds on the outside of the fruit, cashews are one. I have theorised that the fruit hits the ground seed first; then covered by the rotting fruit, is provided with water and initial shelter from the sun in early development. (But as I say, a theory)

Search past threads for the great berry quandry.

As for peanuts, christ only knows.

Oh spanish nuts can have 3 seeds per pod

The really freakish thing about strawberries is that the don’t really even NEED seeds. They can reproduce just fine through multiplication, kind of like daffodils. The fruits help spread them of course, so that whatever eats the berries deposits the seeds somewhere else amidst a nice steaming pile of feces.

As far as peanuts, damned if I know.

However, the cashew “fruit” is not (botanically) a fruit. The seed (nut) and coverings are the “true” (botanical) fruit of the cashew true.

Yes, peanuts, which are legumes (members of the pea family) flower above ground. The flower stalk then pushes its way underground, where the peanut itself develops. In species of wild peanuts, of which there are many in South America, this peculiar habit is thought to be an adaptation that promotes seed survival in dry periods. (See here).

The domestic peanut is actually a cross between two wild species. Because it is tetraploid (having four sets of chromosomes, instead of the two sets found in normal, diploid species) it must self pollinate. One of the wild species ancestors has been identified, but the other is still unknown.

I have often found three-seeded peanuts in bags of unshelled nuts, and four-seeded ones are not that uncommon.

What you’re describing here is an aggregate fruit - a single fruit derived from the fusion of multiple pistils. Arguably, this includes the strawberry. The strawberry flower has multiple pistils. Each pistil contains a single ovary that, when fertilized, develops into the fruit. These are the little hard structures on the surface of the strawberry. That’s right, botanically speaking they’re not just seeds but true fruits in and of themselves. Now the large red juicy structure to which the fruits (formerly ovaries) are attached develops from the floral receptacle. When a fruit includes structures derived from non-ovarian tissue, then this is term an accessory fruit.

So, you’re right. The strawberry is an accessory fruit. But your description was of an aggregate fruit, which the strawberry could also be considered.

I don’t think this is correct in the case of strawberries; the sweet fruit is a lure for small animals, who provide the dispersal service.

OK this has sort of just put me off fruit, the thought that I’m eating “ovaries”…

Guess green peppers and eggplants will be off your list as well?

Tomatoes. Don’t forget tomatoes. They’re are ovaries too.

And of course, seeds are little tiny plant fetuses. So grains should be right out. Why, flour is ground up wheat embyros!

Au contraire. I asked myself this very same question back in the day, and the research through botanical sources revealed to me that nuts ARE, botanically speaking, fruits. I’ll have to go back to dig up my cites, but as far as botanist is concerned, a fruit is any edible part of a plant that has ANYTHING to do with the reproductive process. Apples, cashews, peanuts, peas, cucumbers, corn, peppers, bananas, squash, and potatoes are all types of fruits, botanically speaking. The article then went on to speculate whether broccoli should be considered a fruit since a person consumes pre-flourescent flower buds, but at that point I lost interest.

Ergo, all nuts are fruits, but not all fruits are nuts.

I KILL me.

I counted potatoes, peanuts, and peas among fruits, but they’re not. Since they are not matured ovaries, they are botanically classified as legumes, completely different from fruits or vegetables. :smack:

Here’s a link to the SD Mailbag:


BTW: Wheat is also a fruit. Freakish!

Potatoes are not fruit. Potatoes have nothing to do with sexual reproduction of potato plants. Potatoes are tubers, or modified stems.

But this link says legumes ARE fruit! And so are carrots! What the heck??


Screw this. I’m not eating anything but meat and dairy from now on.

(And potatoes are tubers, their own thing altogether.)

Peanuts are fruits as long as they’re still in the shell. The nuts themselves are seeds. Peas are also seeds. If they’re still in the pod, then they’re fruit.

brane damaj, you’re being confused by the word commonly used for the edible part of the plant being used for the entire plant:

Carrots are flowering plants. They produce flowers that turn into fruit. The part of the plant that you eat is the root, which are called carrots.

Potates are flowering plants. They produce flowers that turn into fruit. The part of the plant that you eat is the tuber, which is a specialized underground stem. The tuber is commonly called a potato.

Tomatoes are flowering plants. They produce flowers that turn into fruit. The part of the plant that you eat is the fruit, which is commonly considered to be a vegetable called the tomato.

Peanuts are flowering plants in the legume family. They produce flowers that turn into fruit. The fruit is botanically classified as a legume and are commonly known as a peanut. You open up the fruit to get to the edible seeds, which are also known as peanuts.

It’s not the common usage that’s confusing, it’s contradicting authorities that should know better. You can only classify something by its edible parts, since that’s what defines it as a fruit or vegetable. I can live with legumes being a sub-class of fruit, I just wish it was consistent.

But carrots? The URL I listed above distinctly lists the carrot as a fruit. If the carrot bore inedible seeds, it wouldn’t be on the list (after all, I’m sure rhubarb has seeds, but the part we eat is the stalk, and therefore it’s a vegetable). Were they wrong to list the carrot?

Just 'cause it flowers doesn’t make it fruit or vegetable. There are tons of flowering plants with no edible parts at all, and hence they are not listed as vegetable of fruit, since the distinction is meaningless if you can’t eat them.

You are confusing the botanical definition of a fruit with the culinary definition of a fruit. The botanical definition has nothing to do with whether the fruit is edible or not.

From the article you linked to:

Bolding mine.

The article does not list carrots (the root) as a fruit in either the botanical or the culinary sense. It does mention the kind of botanical fruit that the carrot plant has, which is known as a schizocarp, and which would never be considered a fruit in the culinary sense.

Botanically, all plants are vegetables. Colloquially, only edible plants (or edible parts of the plant) are vegetables. Botanically, the fruit is a developed ovary. Colloquially, fruits are the sweet and juicy parts of the plant that often contain seeds.

The part of the carrot that you eat is the root. The carrot plant bears fruit, but you don’t eat those. What’s so hard to understand about that?