Log in

You are here

Editor's Picks

Past IOS President Allen Coombes, Curator of Scientific Collections at Puebla University Botanic Garden, discusses leaf variability in Quercus ceirpes (still image from the documentary)
A new documentary by Maricela Rodríguez Acosta
Website Editor | Feb 17, 2026
Quercus miyagii acorn and dried leaves
A rare oak endemic to the Ryukyu Islands of Japan
Elion Jam | Feb 16, 2026
A moss-covered oak (Quercus orocantabrica) in Mata de Albergaria, Peneda-Gerês National Park, Portugal  © Amit Zoran
Steve Potter reviews a new book that features oaks
Steve Potter | Feb 11, 2026

Plant Focus

Quercus canariensis in Cornwall Park, Epsom, Auckland, New Zealand, the champion specimen in New Zealand, planted in the 1920s, 27.2 m tall with a trunk diameter of 209 cm (G. Collett pers. comm. 2026)  © Gerald Collett
Antonio Lambe shares his views on this threatened oak native to Iberia and North Africa

Distribution and Conservation of Quercus nixoniana in Guerrero, Mexico

Project Contact: Natividad Delfina Herrera Castro. Professor, Universidad Autónoma de Guerrero, Mexico.

Quercus nixoniana herbarium Universidad Autonoma de Guerrero
A herbarium specimen of Quercus nixoniana at UAGC (herbarium of the Universidad Autónoma de Guerrero)

Executive Summary: This project involves field recognition and population monitoring of Quercus nixoniana, a species accepted in the Lobatae section (red oaks). Initially, this species was included under Quercus salicifolia due to its lanceolate leaves, annual fruiting, and distribution in the same geographic region. However, in 2003, Valencia and Lozada, through a detailed review, classified it as a new species due to its completely glabrous leaves and pistillate aments with flowers at the distal end of the peduncle. Quercus nixoniana is a tree found in only one type of vegetation in the state of Guerrero: The Pine-Oak Forest. It grows at altitudes ranging from 1,560 to 2,092 meters above sea level, reaching up to 30 meters in height and a diameter at breast height (DBH) of 2.60 meters. Herbarium collections are relatively few and often poorly geographically referenced. Therefore, it is necessary to determine the exact distribution and the challenges the species faces for its conservation. The UAGC herbarium database shows that collections have been made at various points in the state, suggesting that its distribution is scattered across distant populations in the mountainous region.

Target Species: 
Quercus nixoniana (EN)