Garlic is related to lilies. Some varieties of garlic send up a shoot with a seed head with bulbils. The grower has a choice: leave the seed head called a scape to get big or cut it when small to stimulate the bulb growth. Scapes are delicious - use them as you would garlic.
In Europe people let the scapes get larger and pickle them. I usually chop them up for that fresh garlic flavor before the bulbs are ready to harvest and cure.