A new species of Sicyos (Cucurbitaceae, Sicyeae, Sicyinae) from Mexico and Guatemala. Brittonia 55: 69–72. 2003.—Sicyos lirae is described as a new species from Chiapas, Mexico, and Guatemala. It grows in zones with primary or secondary montane rain forest at elevations between 1400 and 3800 meters. In Guatemala the species is commonly called “güisquil de ratón.” It is similar to Sicyos galeottii Cogn., from which it differs in blade consistency, shape of the stigma lobes, and several important ovary and fruit characters.