The first image is of a woodland bulrush. Perhaps scirpus lacustris, given its size in our back yard.
Wikipedia tells us:
Scirpus species are often planted to inhibit soil erosion and provide habitat for other wildlife. They are also used in some herbal remedies; the plant’s rhizomes are collected in the autumn and winter and dried in the sun before use.
Scirpus species are used as food plants by the larvae of some Lepidoptera species, including Batrachedra cuniculata