Oswaldo Téllez-Valdés

The effects of climate change on the long-term conservation of Fagus grandifolia var. mexicana, an important species of the Cloud Forest in Eastern Mexico

We examined the effects of climate change on the future conservation and distribution patterns of the cloud forests in eastern Mexico, by using as a species model to Fagus grandifolia Ehr. var. mexicana (Martinez) Little which is mainly located in this vegetation type, at the Sierra Madre Oriental. This species was selected because it is restricted to the cloud forest, where it is a dominant element and has not been considered for protection in any national or international law. It is probably threatened due to the fact that it plays an important social role as a source of food and furnishing. We used a floristic database and a bioclimatic modeling approach including 19 climatic parameters, in order to obtain the current potential distribution pattern of the species. Currently, its potential distribution pattern shows that it is distributed in six different Mexican Priority Regions for Conservation. In addition, we also selected a future climate scenario, on the basis of some climate changes predictions already proposed. The scenario proposed is characterized by +2 °C and −20% rainfall in the region. Under this predicted climatic condition, we found a drastic distribution contraction of the species, in which most of the remaining populations will inhabit restricted areas located outside the boundaries of the surrounding reserves. Consequently, our results highlight the importance of considering the effects of possible future climate changes on the selection of conservation areas and the urgency to conserve some remaining patches of existing cloud forests. Accordingly, we believe that our bioclimatic modeling approach represents a useful tool to undertake decisions concerning the definition of protected areas, once the current potential distribution pattern of some selected species is known.

An unusual isopropenyldihydrofuran biflavanol from Tephrosia crassifolia

Abstract The roots and aerial parts of Tephrosia crassifolia afforded an isopropenyldihydrofuran biflavanol and a new chalcone. The structures and relative configuration were established by spectroscopic and chemical methods, and confirmed by X-ray diffraction. Crassifolin is the second 3,4″ ether-linked biflavan-4-ol to be isolated from the genus Tephrosia .

Dioscorea howardiana, a new species in Dioscorea section Trigonobasis (Dioscoreaceae)

Dioscorea howardiana is proposed as a new species from Mexico and Central America as far south as Panama, and is described and illustrated. It most closely resemblesD. liebmannii. Relationships, distribution, and ecological preferences of the new species are discussed.ResumenDioscorea howardianase propone como una especie nueva de México y Centroamérica, es descrita e ilustrada. Es semejante aD. liebmannii. Se discuten sus relaciones, su distribución geográfica y preferencias ecológicas.

Nanarepenta juxlahuacensis (Dioscoreaceae), una nueva especie de Oaxaca, México

A new species, Nanarepenta juxtla- huacensis, from the state of Oaxaca, Mexico, is de- scribed. Its habit and diagnostic characters are il- lustrated, and its relationships are discussed. This species is closely related to N. guerrerensis. It is distinguished from that species by having pistillate inflorescences shorter than the leaves, oblong and smooth capsules, as well as by having tectate-per- forate and punctuate pollen grains.

Cinnamomum kruseanum (Lauraceae), a new species from Guerrero, Mexico

Cinnamomum kruseanum (Lauraceae), collected in the state of Guerrero, Mexico, is described as a new species. The species is illustrated, and its relationships are discussed. RESUMEN. Cinnamomum kruseanum (Lauraceae), colectada en el estado de Guerrero, Mexico, es descrita como una nueva especie. Esta nueva especie es ilustrada, y se discuten sus relaciones con otras especies de Cinnamomum. During the process of identification and curation of H. Kruses Herbarium, a private plant collection recently acquired by the National Herbarium (MEXU), a number of collections have turned out to be undescribed taxa. One of them is the following new species of Cinnamomum. Cinnamomum kruseanum 0. Tellez-Valdes & Villasenior, sp. nov. TYPE: Mexico. Guerrero: Agua de Obispo, Puente el Mosco, falda este del cerro, alt. 850-900 m, 4 mar. 1961 (fl, fr), H. Kruse 620 (holotype, MEXU; isotypes, ENCB, MEXU, MO). Figure 1. Arbor usque ad 3 m alta. Folia 6.3-11.9 cm longa, 3.8-4.8 cm lata, ovato-lanceolata, amplexicaulia, trinervia, apice acuto, cuspidato vel rotundato; basi cordata, superficie adaxiali cinereo-strigulosa vel glabrescenti abaxiali dense cinereo-velutina. Inflorescentiae paniculatae axillares; flores 2-4 mm diam.; tepala 1-2 mm longa, dense minute canescentia; stamina externa et interna oblonga, stipitata; staminodia sagittata, apice apiculato. Fructus 810 mm longus, 6-8 mm latus, ellipticus; cupula valde 6 lobata. Tree to 3 m tall. Stems, leaves, rachis of the inflorescences, pedicels and calyx densely cinereousstrigulose to velutinose. Leaves 6.3-11.9 cm long, 3.8-4.8 cm wide, alternate, blade ovate-lanceolate to sometimes ovate, firmly chartaceous, base cordate, amplexicaulous, with the lobes sometimes overlapping, apex acute to cuspidate to rounded, spreading cinereous-strigulose to glabrescent above, densely cinereous-velutinous below, soft to the touch; petioles 2-4 mm long, stout, cinereous. Inflorescences cymose, up to 13 cm long, axillary; peduncles NOVON 3: 208-210. 1993. 3-8 cm long; pedicels 6-13 mm long, slender; flowers 2-3(-4) mm diam. at anthesis; tepals 6, 1-2 mm long, 1 mm wide, ovate-lanceolate, cream to light brown, persistent, densely canescent with short, thick, gray hairs; hypanthium ca. 1 mm long. Outer 6 stamens 1 mm long, oblong, apex rounded, filaments pubescent; anthers quadrate-ovate; inner 3 stamens 1-1.5 mm, the basal pair of glands sessile to subsessile; staminodia 3, ca. 0.5 mm long, deltoid to ovate, sagittate, apex apiculate, hirsutulous. Ovary glabrous; style 1.0 mm, as long as ovary; peduncles 10-15 mm long. Fruits 8-10 mm long, 68 mm wide, ellipsoid, dark brown, glabrous; seated in a shallow, strongly 6-lobed, brown, fleshy cupule, the lobes 2 mm long, 2 mm wide, ovate; seeds not

Potential areas for conservation of useful flora of the Tehuacán-Cuicatlán Valley, Mexico

In the Tehuacán-Cuicatlán Valley (TCV) a total of 1605 useful plant species have been recorded. All of them, anthropologically speaking, are very important and thus, it is worthy to explore various options for ensuring their conservation. Accordingly, the aim of this work was focused in identifying potential areas for the conservation of useful plant species of the TCV. For doing so, we compared two databases from the TCV. The known and potential distributions were identified for 272 species, using MaxEnt. The distribution data was intersected with a grid of 153 operative geographic units (OGUs) that were used to elaborate the species presence matrixes. An optimization algorithm was applied for both the known and the potential distribution and their respective species accumulation curves were compared. A list of 583 useful plant species of the TCV was obtained. These species are heterogeneously distributed in 111 of the 153 recorded OGUs. Ten families contribute with 55.06% of the overall plant richness of the TCV. In addition, the analysis revealed that at least, 13 OGUs are needed to conserve 81% of the useful flora, which represents approximately 30% of the flora, in only 8.5% of the total TCV surface. The selected sites coincide with those areas where some incipient domestication processes, as well as, plant endemism and richness centers have been reported.

Two new species of Dioscorea (Dioscoreaceae) from Peru

Two new species ofDioscorea,D. gentryi (subgen.Helmia sect.Monadelpha) andD. andromedusae (subgen.Helmia sect.Centrostemon) from Peru, are described and illustrated.