Why do citrus fruits sometimes have more seeds than others?

Factual Questions
1

I like lemons. I like to cut them up and eat them with a little salt.

Sometimes I’ll get a lemon than might have 1-2 seeds. Other times I’ll get one that has a dozen or more.

What causes this?

2

Some are sterile hybrids grown from grafting.

3

Is there any way to tell which are which just by looking at them?

4

There wouldn’t be a way to tell unless you knew what cultivar the lemon was. Some Lemon cultivars are seedier that others.

If you have your own lemon tree and you also have a tangerine tree (a seedy cultivar like ‘Dancy’), the bees could bring over some of the tangerine pollen to the flowers on the lemon tree and you might get seedier lemons.