Thrinax is a small genus of fan palms in the family Arecaceae (order Arecales), native to the Caribbean. The genus is characterised by its small, bisexual flowers borne on slender stalks, and fan-shaped (costapalmate) leaves typical of the palm subfamily Coryphoideae. Thrinax is closely allied to the genera Coccothrinax, Hemithrinax, and Zombia, and together they form part of the tribe Cryosophileae — a grouping of New World fan palms.
The taxonomy of Thrinax has been refined over recent decades. In the first edition of Genera Palmarum (1987), Natalie Uhl and John Dransfield placed the genus in subtribe Thrinacinae within tribe Corypheae. Subsequent molecular phylogenetic studies revealed that the Old World and New World members of that subtribe are not closely related, leading to the transfer of Thrinax and allied genera into the exclusively New World tribe Cryosophileae. A further revision in 2008 removed Leucothrinax morrisii (formerly Thrinax morrisii) as a separate genus, after analyses showed its retention in Thrinax would render the genus paraphyletic.
The most widely known species is Thrinax radiata (Florida thatch palm), a slender coastal palm found throughout the Caribbean and southern Florida.
Distribution
Thrinax is native to the Caribbean region. Species occur on Caribbean islands and, in the case of Thrinax radiata, extend into the Florida Keys and coastal southern Florida.
Taxonomy Notes
Thrinax was originally placed in subtribe Thrinacinae, tribe Corypheae (Uhl & Dransfield, 1987). Molecular phylogenetics later showed the Old World and New World Thrinacinae are not sister groups, prompting transfer of Thrinax into the New World tribe Cryosophileae. In 2008, Leucothrinax morrisii was segregated from Thrinax to preserve the genus's monophyly.
