Range Description

B. patula is endemic to two islets in the Madeira archipielago, Portugal: Ilhéu do Desembarcadouro in the region of Ponta de São Lourenço in the eastern part of mainland Madeira, and Ilhéu Chão in the Desertas Islands to the southwest of mainland Madeira—both small, uninhabited islets. Ilhéu do Desembarcadouro covers an area of 1.8 km², while Ilhéu Chão covers an area of approximately 0.5 km². On Ilhéu do Desembarcadouro, wild beets show a patchy distribution pattern. B. patula has been recorded at six sites on the islet and shares the habitat with B. vulgaris ssp. maritima and Patellifolia procumbens at five of these sites. On Ilhéu Chão, B. patula is found only at one site where it grows alongside B. vulgaris ssp. maritima and Patellifolia procumbens (Frese and Carvalho in prep.). The extent of occurrence (EOO) is approximately 70 km² and the area of occupancy (AOO) is less than 10 km².