Clusia chuj (Clusiaceae), a new tree species from the border between Guatemala and Mexico

Summary Clusia chuj (Clusiaceae) is described and illustrated. This new taxon differs from the other species of the genus by being a tree up to 15 m tall with many-flowered inflorescences. The non-resiniferous, quadrangular flowers have thick, pale-yellow petals, and the androecium in the staminate flowers have 20 (– 30) free, short stamens. This new species is mainly found in mountain forests around Tziscao and Yolnabaj lakes near the border between Guatemala and Mexico.