Guadua guzmanii (Poaceae: Bambusoideae: Bambuseae: Guaduinae): A new woody bamboo species endemic to Jalisco, Mexico

Guadua comprises 35 described species, seven of which are distributed in Mexico. Since 1976, a specimen corresponding to the genus Guadua was collected, which could not be correctly assigned to any described taxon. In the present study, a new species of Guadua endemic to the state of Jalisco is described based on vegetative characters. Herbarium specimens were reviewed, field collections made, and specialist literature consulted. A comparison with similar specimens was conducted. The degree of threat was determined following the criteria of the International Union for Conservation of Nature (IUCN). Guadua guzmanii, endemic to the El Tamarindo peninsula, municipality of La Huerta, Jalisco, is described. We include a morphological key for the species of the genus Guadua in Mexico, an illustration, photographs, and a distribution map. According to the IUCN criteria, the species is classified as Critically Endangered due to its restricted geographical distribution. With the description of Guadua guzmanii, the number of native Guadua species in Mexico increases to eight. Additionally, the number of woody bamboos in Mexico increases to 60, with 43 species endemic to Mexico and four endemic to Jalisco, included: Chusquea contrerasii, Chusquea guzmanii, Rhipidocladum singuliflorum, and Guadua guzmanii.