Thanks to: FOAF
Submitted: June 11th, 2004
Identifying a true preflower is way to tell sex before 12/12. That way you can take clones from the known females without wasting the time and space on males.
(Kifit) "do not try to sex a seedling based on the very first preflower you see with a 25x times microscope.....wait and make sure. The time between using a 25x to spot the very first preflower sex and the plant dropping pollen is at least 10+ days away and so it's safe."
"It's best to cull a male only after you are 101% sure - when you see 2 or 3 (or more) immature male flowers bunched together on the internodes or the top growing tip - this is a male, for sure, females preflowers have white " spears " that appear in a vee. ..but "every now and then a sexually indistinguishable flower appears" (Ed Rosenthal)
After a few weeks in veg, plants will begin to show their sex. Usually the males show first. The male preflower is a miniscule ball. It appears that there is a small piece of foliage that covers the ball and protrudes outward when the male preflowers first appear.
The following pics show MALE preflowers the FIRST day they show their future pollen distribution centers.
Many times preflowers will appear at the fourth or fifth node, whereas the plant is on the 7th or 8th node. These preflowers usually don't develop into full flowers, but are only an indicator of the plants sex.
Female on left, male on right. Im only certain about the sex cause I watched them several more days. 25X magnification.
Image credit to: FOAF