First Report of Arceuthobium hondurense in Mexico

Honduran dwarf mistletoe (Arceuthobium hondurense Hawksw. & Wiens) is a rare dwarf mistletoe previously known only from Honduras (1,2). In March 2000 we collected a dwarf mistletoe from approximately 7 km west of San Cristobal de las Casas, Chiapas, Mexico near Route 190 (elevation 2,440 m), which was morphologically similar to A. hondurense (1). This population had initially been classified as A. nigrumHawksw. & Wiens (1). However, our morphological measurements and analysis of nuclear rDNA ITS sequences of A. hondurense plants from Honduras (GenBank No. AF325969) and the plants from Chiapas (AF325970) have confirmed that the Chiapan population is A. hondurense and not A. nigrum. An additional population of A. hondurense was discovered in Chiapas approximately 11 km west of Oxchuc near Route 186 (elevation 2160 m). Both of the Chiapan populations of A. hondurense were parasitizing Pinus tecunumanii(Schw.) Eguiluz et Perry. Specimens of A. hondurense from Chiapas were deposited at the Deaver Herbarium, No...