Haplostachys (honohono) is a genus of flowering plants in the mint family, Lamiaceae, first described as a genus in 1888. The entire genus is endemic to the Hawaiian Islands, although 4 of the 5 known species that have been placed in the genus are now believed to be extinct, the fifth listed as "Critically Imperiled."

Species

• †Haplostachys bryanii Sherff - Molokai but apparently extinct
• Haplostachys haplostachya (A.Gray) H.St.John - Kauai, Maui, Hawaii; Critically Imperiled
• †Haplostachys linearifolia (Drake) Sherff - Maui, Molokai but apparently extinct on both islands
• †Haplostachys munroi C.N.Forbes - Lanai but apparently extinct
• †Haplostachys truncata (A.Gray) Hillebr. - Maui but apparently extinct

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