Some things come in 6-packs, such as soda pop. Others come by the dozen, or the hundred.

Patrols are told to bring a sample of groups of 1, 2, 3, ... as high as they can go. For example, a sprig of poison ivy would be a group of 3 leafs. :-)
Give a time limit - 30 minutes, 9am the next day, or maybe the next time we meet.
Decide if photos of the items are allowed or if they need to bring actual items.

Be sure to explain that only common groups will be counted - bringing 7 flowers doesn't count as 7, but a flower with all of its 7 petals would count.

Give 3 points for each sample.
Give 3 bonus points for each run of three groups in a row. For example, a group of 7, 8, and 9 would earn 3 points, 3 points, 3 points, plus 3 bonus points = 12 points.