Typically a marijuana plant can be female or male, but occasionally you will find a hermaphrodite in the mix. Male cannabis plants will produce a pollen that, when combined with female flowers, will produce seeds. Female cannabis plants will either be pollinated by the male and make seeds or not be pollinated and produce THC within the flowers and buds. A female cannabis plant that does not get pollinated is called sinsemilia, which means without seed. Growers typically find 30-50% of their cannabis crop is male.
The typical look of a male marijuana plant is tall, showing stout stems and sporadic branches with only a couple leaves. (See picture below) Most males end up harvested unless they are used during pollination for breeding once they are known to be males but before pollen comes off of the plant. During harvesting, especially if you happen to have these plants near the females, you will want to cut the plant off right at the stem. You will want to keep the plant as undisturbed as is possible to avoid accidental pollination. Once males enter the flowering stage, each branch tip will have tiny buds (balls) that do not get the hairs that female plants will get. Outdoor male marijuana plants can start flowering as early as the middle of July for some varieties. The specific varieties that are used to the hottest southern climates may wait until the middle of September. Each variety has a slightly different cycle to determine when this happens, so cutting off the male at the right time will be different for each variety.
For growers who are not sure about the variety of marijuana they are growing, you will have to dedicate time weekly to visit your plants from the middle of July until the middle of September to ensure you do not miss the proper window to harvest these plants. Sexing the male marijuana plants is crucial to any chance at a successful harvest. If you do not time this right, you will end up with quite a few marijuana seeds and little harvest to show for your work.
The female marijuana plant will not have any buds (balls) but it will have some tiny white hairs growing off the ends of the branches. (See picture below) Many varieties of marijuana plants that are used to more temperate climates will start to show off their gender around the end of July (or the end of January if you live below the equator). Some female marijuana plants will end up never producing pollen buds but instead will be purely sinsemilia, so harvesting these plants will allow for a sweet and gentle smoke. It cannot be stressed enough how important it is to remove all of the male plants at the right time because you do not want to risk pollination of your female plants. At early stages of flowering, male plants look quite different than female plants when looking at the tips of the branches. The best indicator of gender is the primordial, which will come out along the side of either the third or the fourth internode along the main stem. Growers will notice a "V" shaped pistil when looked at closely. Males, when grown outside, will typically begin to show their characteristics about three weeks ahead of the female plants. When the plants are grown indoors, the time is decreased to 7-10 days. We have heard every urban myth out there about how anything from the stage of the moon to chemicals added into the soil can help you determine the sex of your cannabis plants, but we would recommend looking it up from a reliable internet source (such as here) or a book until you have the experience yourself.
A Hermie, also known as a hermaphroditic form of marijuana plant, is a cannabis plant that is truly one gender that somehow has developed the sexual organs that should be on the other gender of plant. Typically you will find a female cannabis plant in bloom that has developed staminate flowers, but you can find the opposite occasionally as well. Most growers will not recognize a male hermaphrodite due to the fact that only a handful of growers will even allow the male marijuana plants reach flowering to where they would see the pistillate. Most growers do not favor their hermaphroditic marijuana plants because they can release some pollen, ruining an entire sinsemilia crop (including themselves) and the seeds that come from this pollination are considered totally worthless. The seeds will end up with mostly hermaphroditic plants so it will end up being a poor crop. [Please note that rarely a staminate marijuana flower will show up near the end of flowering on a female marijuana plant, but this is not considered deleterious hermaphroditism because no pollen drops.]