Plants that produce Floral Scent germs are not marked as a germ source in the germ overlay, even though there are floral scent germs being produced around them. It makes it difficult to determine where exactly the germs are coming from; I know ripe bristle berries will produce germs, but not sure which other plants produce them.
somewhat related: pufts are marked as a germ source, but appear to not produce slimelung germs.
Turn on germ overlay F9 to view germs around a ripe plant to view Floral Scent germs. No source is shown.