TROPICAL PLANT ENCYCLOPEDIA
Dichromena sp., Rhynchospora sp.
Star Grass, Star Rush, White Topped SedgeFamily: Cyperaceae
The "leaves" are actually large bracts that surround the less-conspicuous inflorescence. The bracts are white at the base, becoming green at the tips.
Link to this plant:
https://toptropicals.com/catalog/uid/dichromena_sp.htm