series (of publications); library (set of books)
dense growth; thick growth; gregarious growth; growing in clusters
treatise or essay collection
gut microbiota; gut flora; intestinal flora; gut microbiome
a number of interesting stories; book containing a number of interesting stories
choroid plexus; chorioid plexus
bacterial flora; microbiota
one red flower standing out in a sea of green vegetation; one item of quality standing out among many; one woman among many men