Miguel Ángel Muñiz-Castro

Distance effect from cloud forest fragments on plant community structure in abandoned pastures in Veracruz, Mexico

Secondary succession was studied in a Mexican cloud forest region along a chronosequence of 15 abandoned pastures (0.25–80 y). Our objective was to determine the effects of distance from the forest border on successional vegetation structure and woody species richness along the chronosequence. Vegetation structure similar to that of mature forests recovered over 40–50 y, both close to (0–10 m) and away from (40–50 m) the border. Total woody species richness was similar for both distances but species composition differed significantly. When primary forest species were analysed separately, basal area, height, abundance and richness were all significantly higher close to the forest border. Primary species such as Quercus spp. (barochorous-synzoochorous) and Carpinus caroliniana (anemochorous) had lower basal area, density and height away from the border than close to it. Secondary species such as Lippia myriocephala (anemochorous) and Myrsine coriacea (endozoochorous) did not differ in their rate of colonization between distances. The limitation of seed dispersal and establishment for primary woody species away from forest borders suggests that propagules need to be introduced to accelerate forest restoration.

Echeveria yalmanantlanensis (Crassulaceae): A new species from Cerro Grande, Sierra de Manantlán, western Mexico

Echeveria yalmanantlanensis, a new species from eastern Sierra de Manantlán, Biosphere Reserve, on the Jalisco-Colima border in western Mexico, is described and illustrated, and a table for comparison of morphologically related taxa is provided. This species belongs to series Valvatae, differing from the other members of the series by its acaulescent habit, shape and color of leaves and bracts, size of scape, bract pattern on scape, size and color of the corolla, habitat, and geographic distribution. There is support for the hypotheses that this species is endemic to the calcareous massif Cerro Grande and is already in danger of extinction.ResumenSe describe e ilustra Echeveria yalmanantlanensis, una especie nueva de la Sierra de Manantlán oriental, en los límites de los estados de Colima y Jalisco, occidente de México; se provee un cuadro comparativo para la identificación de taxones relacionados morfológicamente. Esta especie pertenece a la serie Valvatae, difiere de los otros dos miembros de la serie por su hábito acaulescente, forma y color de sus hojas y brácteas, tamaño del escapo, patrón de brácteas en el escapo, tamaño de la corola, color de sépalos y de corola, distribución geográfica y hábitat. Se apoyan las hipótesis de que esta especie es endémica del macizo calcáreo Cerro Grande y de que se encuentra en peligro de extinción.

Four New Species of Agave (Agavaceae) of the Marmoratae Group

Abstract We present a re-evaluation of the taxonomic status of Agave gypsophila, for which a narrower circumscription is proposed, and four new species from western Mexico are described and illustrated: Agave abisaii, A. andreae, A. kristenii and A. pablocarrilloi . All four species are narrow endemics occurring on a variety of limestone outcrops and belong to the subgenus Agave and to the Marmoratae species group sensu Berger. They are morphologically related to A. gypsophila s. s. from Guerrero, Mexico, but clearly differ from it in various qualitative and quantitative morphological and ecological characteristics.

Agave temacapulinensis (Agavaceae), a New Ditepalous Species from the Los Altos Region, Jalisco, Mexico

Abstract.  Agave temacapulinensis A. Vázquez & Cházaro (Agavaceae) is described and illustrated from Jalisco, Mexico. The new species belongs to Agave L. subg. Agave and is a member of the Ditepalae group, sensu Gentry. It is related to A. wocomahi Gentry in terms of its rosette size, solitary habit in most cases, the smooth texture of the leaves, the red-tipped dimorphic tepals, and the deep floral tube. Agave temacapulinensis differs from A. wocomahi in having light gray, glaucous rosettes (vs. dark green to glaucous green); short acuminate leaves (vs. long acuminate); crenate margins (vs. straight to undulate) with smaller marginal teeth (8–10 mm vs. 10–20 mm); larger panicles (5.5–6.5 m vs. 3–5 m) with more lateral branches (16 to 18 vs. 8 to 15); and smaller seeds (5–6 × 3–4 mm vs. 7 × 4.5–5 mm). Resumen.  Una nueva especie, Agave temacapulinensis A. Vázquez & Cházaro (Agavaceae), es descrita e ilustrada de Jalisco, Mexico. Pertenece a Agave L. subg. Agave y corresponde al grupo Ditepalae sensu Gentry. La especie está relacionada con A. wocomahi Gentry en términos de tamaño de roseta, hábito no surculoso en la mayoría de los casos, textura suave de las hojas, tépalos dimórficos con puntas rojizas y tubo floral profundo, pero difiere de ésta ultima por poseer rosetas de color glauco-gris claro (vs. verde oscuro-verde glauco); hojas cortamente acuminadas (vs. largamente acuminadas); márgenes crenados (vs. rectos a ondulados); con dientes más pequeños (8–10 mm vs. 10–20 mm); panículas más grandes (5.5–6.5 m vs. 3–5 m) con más ramas laterales (16 a 18 vs. 8 a 15); y semillas más pequeñas (5–6 × 3–4 mm vs. 7 × 4.5–5 mm).