Cattleya rex

Epiphytic herb with cylindric or spindle-shaped pseudobulbs, up to 35 cm. high, with one leaf at the top.^[1][2] Leaf oblong or elliptic-oblong, obtuse, light green, up to 35 cm. long and up to 6 cm. wide, coriaceous.^[1][2] Inflorescence up to 20.3 cm. high, with 3 to 6 (or 10) flowers.^[1][3] Flowers large and showy, up to 17 cm wide, with sepals and petals being cream-colored or ivory white, except the lip or labellum, which is colored with yellow, rose and red.^{[1][2][4][5][3]} Sepals narrowly elliptic; petals ovate, elliptic or rhomboid; lip folded to form a tube, with very wavy front margin.^[1][2][4][3] Pollinia 4, with curved appendages.^[2]

James O'Brien described the species for the first time in 1890 from a live flowering plant collected in the area of Moyobamba, San Martín by Mr. Bungeroth and cultivated at L'Horticulture International, Brussels, by Mr. L. Linden.^[1][2][4][5] That was the first known flowering plant outside the native habitat of C. rex.^[2][4]

Cattleya rex is known from a few localities in the regions of San Martin and Puno in Peru and the department of La Paz in Bolivia.^[1][6][7][8] It occurs in montane forests and low montane seasonally dry forests at 800–2500 m, growing on tree branches.^[6][7][8]

In its native habitat, flowering occurs between December and March.^[6]

Cattleya rex has been assigned an endangered conservation status in 1997 by the IUCN.^[9] Previously believed to be a Peruvian endemic, in 2013 a new locality was reported in Bolivia, thus increasing the area of extension for the species.^[8]