A New Species of Beilschmiedia (Lauraceae) from Guerrero, Mexico Francisco G. Lorea Herndndez Departamento de Biologia, Facultad de Ciencias, UNAM, Ciudad Universitaria, Circuito Exterior, 04510 Mexico, D.F., Mexico. Current address: Missouri Botanical Garden, P.O. Box 299, St. Louis, Missouri 63166-0299, U.S.A.ABSTRACT. Beilschmiedia angustielliptica is de-scribed and illustrated. Morphologically this speciesis easy to recognize because of its long, reticulate(but not foveolate) lanceolate leaves, its glabrousanthers, and its glabrate ovary. So far, this speciesis known only from the central mountains of Guer-rero, Mexico.RESUMEN. Se describe e ilustra Beilschmiedia an-gustielliptica. Entre las otras especies del generoesta nueva especie es facil de reconocer por sushojas grandes, lanceoladas, reticuladas (pero no fo-veoladas), sus anteras glabras, y su ovario glabrado.Hasta ahora esta especie solo se conoce de las mon-taiias centrales de Guerrero, Mexico. Extensive collections carried out during the lastten years in Guerrero, Mexico, under the auspicesof the "Flora del Estado de Guerrero" project, or-ganized by the Laboratorio de Plantas Vasculares(Facultad de Ciencias, UNAM), have resulted inmore complete collections for several formerly poor-ly known families in that state. For example, abouta dozen species of Lauraceae were previously re-ported from Guerrero (Standley, 1922; Allen, 1945).Today, the assembled material represents more than35 species. Several collections belong to undescribedspecies in different genera. A new species of Beilsch-miedia is here described. The Latin American species of Beilschmiediawere last revised more than 50 years ago by Kos-termans (1938), who recognized 15 neotropical spe-cies in the genus. Currently, the increase in collec-tions suggests the merger of some names, but alsothe recognition of new species, so the actual numberof taxa is around 10-20 species (van der Werff,1991). In Mexico there exist about eight species ofBeilschmiedia. For a time, only B. mexicana (Mez)Kostermans was recognized as occurring in thecountry (Kostermans, 1938; Allen, 1945). SeveralMexican specimens of Beilschmiedia have been an-notated in herbaria as B. pendula (Swartz) W. B.Hemsley, implying the presence of this species inthe region. But B. mexicana is suspected to be asynonym of B. pendula (Burger & van der Werff,1990). Early in the second half of this century B.riparia F. Miranda was described from Chiapas(Miranda, 1953) as a distinct species with pilose andsubcoriaceous leaves; this species is now known fromthe tropical semideciduous forests in Guerrero, Oa-xaca, and Chiapas. Besides B. pendula, B. riparia,and the newly described species, several collectionsfrom different places in Mexico indicate the presenceof at least five other taxa, some of them conspecificwith or related to species known in Mesoamerica,namely: B. anay (S. F. Blake) Kostermans, B. hon.durensis Kostermans, and B. ovalis (S. F. Blake)C. K. Allen. Until a thorough revision of the American speciesof Beilschmiedia is done, I present the followingprovisional key to separate the Mexican species.KEY TO THE MEXICAN SPECIES OF BEILSCHMIEDIA1 a. Leaf undersurface glabrous, rarely some straight appressed hairs on main veins. 2a. Leaf undersurface finely reticulate (can-cellate), minor veins evenly thickened forming areolae 0.1-0.3 mm diam., no or almost no free veinlets. 3a. Leaves stiff coriaceous, rather thick, obtuse to acute ....... B. aff. mexicana 3b. Leaves chartaceous, acute to long acuminate............... B. mexicana 2b. Leaf undersurface roughly reticulate, mi-nor veins unevenly thickened, then areolae usually 1.0 mm diam. or larger and ap-pearing with several free veinlets. 4a. Secondary veins in 14-18 pairs, leaves narrowly elliptic .................. .................... B. angustielliptica 4b. Secondary veins in 8-10 pairs, leaves elliptic ................ B. hondurensislb. Leaf undersurface pubescent, if hairs only on main veins, these not straight appressed. NoVON 5: 45-47. 1995.