Howdy Cunjo420, Those 'spikes', as You called them, are stipules. They appear at or just below the growth nodes. They appear on both male and female plants. The bud sites will show, first pre-flowers, then male or female flowers, in the 'crotch' of the stem and leaf stem after the plant goes into bloom. Some growers believe that the stipules are an early sign of the plants gender, crossed for female and pointing out for male. In the last nine grows, I can say that most, but not all, of my female plants had crossed stipules on them. Similar 'appendages' appear on other plants like vines and other climbing plants. Since cannabis is in the same family as hops, it just might be a 'left over' part from way back when it was a 'climber', just My assumption.