Horns on Bud

Technically, the plant is "re-flowering" in a final attempt to get pollinated, since it can sense that time is almost up for the plant and it does not have any seeds yet. The main flowers are past their reproductive prime, so the plant sends out a few new fresh female calyxes in the hope of reproducing before she dies. You could harvest from now to one week more tops, if it were my plant. The re-flowering or foxtailing as it is also known is nothing to worry about and will smoke just as satisfyingly as the rest of the buds. If you are really stressed by it, reducing your lighting by two hours while you wait for harvest day will reduce and slow the amount of re-flowerings. Judge your maturity off of the main flowers not the "horns"/re-flowering parts.

They are called foxtails and can be natural or stress I

Agree with others. Fox tailing. Some strain do this, other do it under heat stress or late in flower when it should be chopped. Good Luck!

this is "fox tail"

could be genetic.. could be light related. Both too much and too little can have this effect. if it's only at the top, good chance it's the 'too much' version, obviously. if larfy you can just prune it off when you trim. I've had knobby buds where the knobs were just as dense and of similar quality as the rest of the cola. Just not as pretty, but that's irrelevant to me. looks like newer growth, so i'd focus on the trichomes from the bulk of the normal growth as you normally would... i wouldn't over-ripen the plant to get a few fractions of a gram to ripen at the top. Again, if it doesn't keep up, can prune it off.. use for edibles or whatever else..