NOTES Caribbean Journal of Science, Vol. 42, No. 2, 244-246, 2006 Copyright 2006 College of Arts and Sciences University of Puerto Rico, Mayagu ¨ ez Montanegra arenaria (Agaricaeceae, Basiodiomyocota), a New Record for Puerto Rico ÁNGEL M. NIEVES-RIVERA 1, * AND MARY CATHERINE AIME. 2 1 Department of Marine Sciences, University of Puerto Rico, P.O. Box 9013, Mayagüez, PR 00681-9013. 2 USDA- ARS Systematic Botany and Mycology Labora- tory, Bldg. 011A, Rm. 319, BARC-West, 10300 Baltimore Ave., Beltsville, MD 20705. cathie@nt.ars-grin.gov. *Corresponding author: anieves@coqui.net ABSTRACT.—The euagaric Montagnea arenaria (Basidiomycota) is reported from a dry region of southwestern Puerto Rico. This is a new record for Puerto Rico, and only the second record of this fun- gus in the Caribbean. The Puerto Rican material is completely described and illustrated, and a brief taxonomic discussion provided. KEYWORDS.—Montagnea, Agaricales, basidiomyce- tes, desert gasteromycete, xeric forest, West Indies, Caribbean Montagnea arenaria (DC.) Zeller is a true desert-adapted gastroid mushroom with a subagaricoid, stipitate basidiocarp and a powdery gleba, occurring in xeric habitats throughout the world. Members of Montag- nea Fr. have ellipsoid, smooth, dark basid- iospores that are windblown, not forcibly discharged like most agarics. Edibility of Montagnea basidiocarps is unknown be- cause they are usually tough and dry when they are first seen. The fungus is especially well adapted for dry and desert environ- ments and appears to be widespread in these habitats (Rauschert 1964). In the west- ern hemisphere this fungus has been re- ported from Argentina (Rauschert 1964), Brazil (Baseia and Milanez 2002), Mexico’s Pacific coast (Chen 1999), and the south- western USA (Rauschert 1964; Chen 1999). Additionally, M. arenaria was reported from sandy soil from Cienfuegos and Guantánamo in Cuba by Kreisel (1971) and Minter et al. (2001) reported the same taxon in Cuba under the name M. radiosa. There are no other known reports of this fungus from the Caribbean. While accompanying a paleontological survey team to El Rayo Formation (18°01.640'N, 66° 55.571'W, 100 m in eleva- tion; Late Cretaceous in age) in eastern Sabana Grande (Martínez Colón 2003), one of us (AMNR) found several specimens of M. arenaria that are herein reported as a new record for Puerto Rico. The lifezone is classified as subtropical dry forest (dry- volcanic-sedimentary-limestone) according to the Holdrige system and the new map- ping system (Helmer et al. 2002). DNA extraction, amplification, and sequence analysis.—Sequences were obtained from dried material from BPI 843720 (deposited in the U.S. National Fungus Collections, Beltsville, MD), and extracted with the UltraClean Plant DNA Isolation kit as per the manufacturer’s instructions (MoBio Laboratories, Inc., Solana Beach, CA). The nuclear DNA coding for the large (25S) ri- bosomal subunit was amplified and se- quenced as described in Aime et al. (2005); the sequence has been deposited in Gen- Bank (#DQ177285). Montagnea arenaria (DC.) Zeller, Mycologia 35:418, 1943. (Fig. 1) Pileus 12-39 mm in diameter, plane with flattened umbo or sometimes broadly con- vex, with an undulating, sulcate-striate margin, minutely pubescent towards the center dry, dull, gray brown (Fig. 1). Lamel- lae free, 0.2-0.5 mm in width, regular to crisped, margin eroded, concolorous, black; lamellulae of two lengths or tiers. Stipe 24- 81 mm long × 0.3-0.5 cm wide, equal, re- curved squamulose or fibrillose, having a scaly-fibrous ringed volva, light buff to pale true cinnamon at maturity (Fig. 1). Spores 3.2-4.9 × 5.3-7.6 m, Q = 1.60, ovoid to ellipsoid, opaque, smooth, thin-walled, ms. received September 21, 2005; accepted April 4, 2006 244