The gender of a bell pepper can be identified by counting its lobes.
Bell peppers come in a variety of sizes and colors, and, according to a popular internet rumor, a variety of genders as well:
A section on the reproductive biology of peppers in The Encyclopedia of Fruit and Nuts notes that bell peppers come from flowers possessing both male and female sex organs:
Pepper flowers are complete and perfect, that is they have a calyx, corolla and male and female sex organs. The flowers are protogynous, but readily self-pollinate.
David Karp, a pomologist at UC Riverside, also addressed the rumor of bell pepper gender in 2013:
The supposition that there are male and female peppers is a common canard, but untrue. Peppers grow from flowers that have both male and female parts. The fruits do not have a gender.
While bell peppers are neither male nor female, some food blogs have insisted there is still some usefulness to this widespread rumor. For example, the Garden Frugal writes that while it is not scientifically accurate to label bell peppers male or female, assigning a gender may help cooks remember how to choose the right peppers:
Describing peppers as a gender is not accurate, because bell peppers are hermaphroditic. The gender reference is used only as a memory aid to help select the best bell pepper for each purpose either eating raw, seed collection, or for cooking. There is a simple method for identifying which bell pepper has the traits you desire. Peppers with four lobes are female and those with three lobes are male. The female peppers with more lobes, contain more seeds are best for seed collecting and growing new plants (hence female). They are also sweeter when eaten raw. The male peppers with three or fewer lobes are better for grilling, cooking. They also contain fewer seeds.
But this claim is also unfounded, as the number of lobes on a pepper does not have any bearing on its taste. And while it could be argued a four-lobed pepper has more seeds than a three-lobed pepper, this has more to do with the overall size of the fruit than the number of lobes.