Thelesperma Less.
Engl.: greenthread.

Thelesperma longipes

Thelesperma longipes Gray.
Engl.: longstalk greenthread.

Thelesperma megapotamicum

Thelesperma megapotamicum (Spreng.) Kuntze.
Engl.: Hopi tea greenthread, Indian tea, Navajo tea.
Span.: cota.
Bot. syn.: Bidens megapotamica Spreng., Thelesperma gracile (Torr.) Gray.

I have no articles for this botanical term, but there might be some for the next level down (if found).