Related Topics: [ wetlands] Grasses are sufficiently familiar that we probably pay them very little attention. Few families can match the grasses for number of species, or for the diversity of habitats they encompass. With the exception of the bamboos grasses are herbaceous. A quick glance at the leaves will tell a grass from a sedge. Whereas a sedge's leaves come out in three directions, grass leaves come out in only two directions - that is, if you were to look at a blade of grass from above, the leaves would appear to form a straight line. Unlike the reeds, grass flowers are usually extremely compact and simple: whereas reed flowers are usually somewhat rounded and bear six tiny petal-like structures, grass flowers are usually restricted to just two tiny modified leaves (glumes) at the base of the flowers.