WordNet sense 1 ((of plants) growing in groups that are close together):

gregarious

WordNet sense 2 (occurring close together in bunches or clusters):

bunchy, bunched

WordNet sense 3 (gathered together or made less diffuse):

concentrated

WordNet sense 4 (clustered together but not coherent):

agglomerate, agglomerated, agglomerative, agglomerate

WordNet sense 5 (forming a whole or aggregate):

collective