This is taboa (Typha dominguensis), a common perennial reed. Very very common! Actually, it has spread to tropical and temperate regions all over the world, in marshes and wetlands, even mangrove swamps. It shoots up to about 2 metres tall and releases millions of seeds, so it quickly takes over any area where it becomes established and can be something of a nuisance.
Has it's uses though. The fibre is tough and durable and can be used to make baskets and handicrafts, even paper. In Turkey the flower stalk is applied to burns and wounds and apparently works quite well.
Perhaps it's most beneficial property though is as a sponge. As it grows, taboa absorbs vast amounts of material from the water around it, most of which accumulates in it's tissues. So taboa beds can absorb Phosphorous from agricultural runoff which would otherwise cause algal blooms, or even heavy metals like Zinc from mining pollution. You just wait and then cut and take away the reeds. There are several studies around the world deliberately making lagoons of Typha dominguensis as a low cost way of cleaning waste water.
It's hard to say whether taboa is such a benefit environmentally. It swamps (as it were) native species in clean water, but cleans polluted water so that other creatures can survive, as well as providing cover for insects and small fish. Anyway, it can be very useful for us humans.