There are about 30 species of crab apple and hundreds of different cultivars.
I opened a book about Malus hybrids and cultivars, but distinguishing between all of them seems like a task for someone who's passionate about crab apples... and only crab apples. Maybe one day... but for now I'm happy to call each and every one by the same name.
The difference between an apple and a crab apple is a matter of size: a fruit with a diameter of two inches or less is a crab apple and anything bigger is an apple. Of course, the line gets blurry near two inches, and that's just the way it is. These crab apples were about an inch in diameter.
There was so much fruit on the tree that supports needed to be put under a couple branches.
Branches still broke under the weight and needed to be cut off.
Here's fruit from the same tree about six weeks after the first close up was taken.
The fruit is now entirely red,
and ripe fruit is falling off the tree. (Walking around here is not for the weak-ankled.)
Here's a different kind of crab apple.
It has a squat trunk and several twisting leaders.
The tree is covered with fruit right now.
The diameter is about a half an inch or less. The size and color remind me of the game Hi Ho! Cherry-O.
This crab apple had already dropped all of its fruit a couple weeks ago, carpeting the ground with the berry-like crabs.
A few oddball crab apples have some blossoms these days. But there are other things flowering out of time, too: rhododendrons, azaleas, saucer magnolias, crocuses, horse chestnuts... The crab apples will bloom again in the spring; there just might not be quite as many flowers.
The spring flowers and fall fruit make this tree highly sought after. If you're looking to plant a crab apple tree, here's a list of ten recommended varieties.