ʻIhiʻihi, ʻIhiʻihilauākea or Hawaiian waterfern
Marsileaceae (Pepperwort family)
Endemic to the Hawaiian Islands (Niʻihau, extinct?; extant on Oʻahu and Molokaʻi)
Oʻahu (Cultivated); Oʻahu variety
Often, Marsilea spp. have been mistakenly sold on the market as "Shamrock" or "Four-leaf Clover." All belong to very different families: shamrock belongs to Oxalidaceae; clover to Fabaceae, peas and legumes; ʻihiʻihi to Marsileaceae, water ferns.
The generic name Marsilea is named for Count Luigi Ferdinando Marsigli or Marsili (1656-1730), Italian botanist at Bologna.
The Latin specific epithet villosa, hairy, in reference to the hairy rhizomes and sporocarps.