Elodea canadensis aka Water Thyme

Elodea canadensis, also known as American waterweed, Canadian waterweed, or pondweed, is a perennial aquatic plant native to most of North America. It is a submergent macrophyte with submerged, branched stems adorned with close-set, recurved, dark green leaves. Although it has been introduced to various regions outside its native range, it was first recorded in the British Isles around 1836. This plant is listed as an invasive non-native species and is banned from sale in Northern Ireland, according to The Wildlife (Northern Ireland) Order (1985), as amended. Despite its invasive nature, Elodea canadensis is also cultivated as a semi-evergreen, aquatic perennial. It is a relatively rare houseplant that is not difficult to grow but requires regular watering to thrive. Ideally, it should be placed in direct light, within a foot of a window, for optimal growth. Belonging to the Elodea genus, this species serves as a representation of North American flora.