What is this plant

https://davesgarden.com/guides/pf/showimage/4469/

looks like Northern Sea Oats Grass

Yes, this is Northern Sea Oats, one of my favorite plants for movement in my garden. It grows beautifully, and looks wonderful as a "hedge" or with -The following information came from https://www.gardeningknowhow.com/ornamental/foliage/northern-sea-oats/northern-sea-oats-grass.htm

Northern Sea Oats Grass – How To Plant Northern Sea Oats

By Bonnie L. Grant

Northern sea oats (Chasmanthium latifolium) is a perennial ornamental grass with interesting flat foliage and unique seed heads. The plant provides several seasons of interest and is a good landscape plant for USDA zones 5 to 8. Northern sea oats decorative grass is native to south and eastern parts of the United States from Texas to Pennsylvania. The plant’s name refers to the spikelets that hang from the plant and resemble oat seed heads. The different forms of the grass make growing northern sea oats grass in the garden an excellent choice.

Northern Sea Oats in the Garden

Northern sea oats decorative grass is a versatile plant that performs equally well in sun or shade. The grass is loosely tufted and forms a clump. The leaves are dark green and long and slightly pointed at the end, resembling bamboo leaves.

The real attraction is the flower’s seed head, which is a wide, flat construction whose texture resembles wheat heads. The flowers are dangling panicles and the foliage turns a rich bronze in fall. The seed heads arrive in summer and persist for three seasons. They are often used as part of cut flower arrangements. The seed heads start out a medium green and age to a light tan color.

Use of northern sea oats in the garden tends to fill large areas when planted in mass and form a swath of motion that enlivens the landscape.

You need to consider the invasive nature of the plant, which grows from rhizomes and seeds readily. The self-sowing nature can cause numerous seedlings and make the grass a nuisance. Cut the seed heads off to prevent spreading and bring them indoors for use in dried floral arrangements. The foliage should be sheared back in late winter to make way for the new spring growth.

How to Plant Northern Sea Oats

Northern sea oats grass is a warm-season grass that spreads through rhizomes. Its hardiness zone can be extended to USDA zone 4 with heavy mulching and if planted in a protected location.

The plant can tolerate very dry conditions or moist soils that are well drained. Plant northern sea oats in a location where you need a 3 to 5 foot tall plant with a similar spread and a drought tolerant specimen. When grown in a shady location the plant is greener and taller, but it still produces flowers and seed heads.

How to Grow Northern Sea Oats

The site and moisture adaptability is not the only attribute to planting northern sea oats. It also is tolerant of sea spray and can be grown on coastal areas. Create rich organically amended soil for planting northern sea oats. Rich, well drained soil in sun is the best situation for how to grow northern sea oats.

The grass is native to wooded slopes and creek bottoms where soils are rich from organic deposits and natural compost. Mimic the natural habitat of any plant you are growing for a successful cultivation. The plant can easily be cultivated by division of the rhizomes in fall or early spring.

Whatever it is it definitely is not unattractive. I like the bracts the picture shows, I assume they will be seed pods eventually. If you keep them they would make a nice addition to other plants, even if you move them to another spot. Collect the seeds in case they don't come back.

You have sea oats. Very pleasant to watch as the gentle breeze moves it about. Many folks cut at ground level and place in a pretty basket for a fall arrangement along with other dried materials. Grows wonderfully here in Kansas. Cold winters do not seem to bother it one bit.