Branch of a Pacific Yew, Taxus brevifolia
|The best-known yews, English
Yews, Taxus baccata, are evergreen shrubs that people plant around their houses.
Those yews are popular because they require little care, stay green year round, and some
people like to clip them so that they have vertical sides and flat tops, making them look
like green walls.
In certain parts of northwestern North America and in some other countries there are yew trees that grow quite large. Yews belong to the genus Taxus and have their own Yew Family, the Taxaceae.
YEWS ARE GYMNOSPERMS
Yews are gymnosperms so they're not angiosperms, which are known as the flowering plants, yet yews do have clusters of sexual parts traditionally referred to as flowers. You can see male "flowers" or stamen clusters below:
Yews are typically dioecious (separate male and female trees). A "flower" from a female tree, consisting of a single naked ovule subtended by several bracts, is shown below:
The male "flowers" fall off as soon as their anthers shed their pollen. The female "flowers" will slowly grow until late summer when they'll develop into a greenish seed almost entirely surrounded by a bright red, gelatinous cup, or "aril." The seed with its red, gelatinous cup often is referred to as the "fruit."
THE YEW "FRUIT"
At the right you see two yew "fruits" which are about the size of small peas. I've removed part of one side of the top "fruit" so you can see that the green item in it resides there like a ball in a red bowl. In the bottom "fruit" you can see the very top of the green item (the seed) peeking from a hole in the bowl-like thing (the aril), which is soft and juicy. Clearly, this is unlike most fruits, so what's going on, and why do I keep putting the word "fruit" inside quotation marks? To understand, we have to think botanically.
On our Gymnosperm Page we say this about gymnosperm fruits:
Their female sex germs reside in ovules, as in regular flowers, but the ovules themselves are not enclosed within the flower's ovaries, as they are among flowering plants.
On our Standard Blossom Page we say that:
So, the gymnosperm definition says that gymnosperm ovules are not enclosed in ovaries and our fruit definition says that fruits develop from ovaries. Does this mean, then, that the yews' juicy, red items can't be real fruits?
Well, according to our strict definitions of what a fruit is, that's exactly what it means. The Yews' juicy, red items are false fruits because they don't develop from ovaries. Still, people often talk about "yew fruits" the same way that they refer to tomatoes as vegetables, though, botanically, we've seen, tomatoes are perfectly good fruits developed directly from tomato-flower ovaries.
Here's what we're seeing in the picture above:
The greenish item inside the juicy, red thing is the seed. When the seed matures more it'll grow darker. In the picture it's green because it's still a bit immature.
The red, juicy, bowl-like thing surrounding the seed is an aril. An aril is a fleshy covering found on certain kinds of seeds. Arils develop from the funiculus, which is the attachment point of the seed to the rest of the plant. Note that the funiculus is not part of the ovary but rather something else entirely. Technically, the yew's aril is considered to have evolved from a primitive cone scale.