Beaucarnea inermis is a threatened plant of the seasonally dry tropical forests of the northeastern Sierra Madre Oriental mountains. It has been affected by habitat loss and fragmentation, mainly from changes in land use and poaching. The number of B. inermis plants, sexual proportion, and structural parameters were recorded in natural populations inside the Sierra del Abra Tanchipa Biosphere Reserve and unprotected sites. Effects of chronic disturbance on demography parameters and asymmetry coefficient were estimated. Average population density is 280 ind*ha À1 inside the protected area and 186 ind*ha À1 in unprotected sites. Life tables indicate a high seedling to juvenile mortality rate, but life expectancy increases in juveniles, suggesting a survival type III curve. Population size distribution skewness indicates differences associated with disturbance. Sex ratio was 0.93:1 (m:f) inside the protected area and 0.76:1 (m:f) in unprotected sites. Anthropogenic disturbance affects life expectancy and the survival and mortality rates mainly in early life classes; however, once the adult stage is reached, mortality rate is reduced and survival rate increases. The natural protected area represents a refuge for the species from the effects of anthropogenic disturbance and illegal poaching. Additional studies are needed to evaluate the genetic diversity in B. inermis in protected and unprotected sites, and how it is affected by disturbance. Also, it is important to highlight other species inside the protected area such as Dioon edule, Zamia fischeri, and Stanhopea tigrina, which are considered as endangered or threatened.
Antecedentes: La Sierra Madre Oriental es una Provincia Fisiográfica ubicada en el noreste de México con características geológicas, climáticas y edáficas distintivas. La flora de esta región aún no ha sido inventariada en conjunto.
Preguntas: ¿Cuál es la diversidad florística de la Provincia Fisiográfica de la Sierra Madre Oriental? ¿Cuál es la afinidad geográfica de sus géneros?
Sitio y años de estudio: Provincia Fisiográfica de la Sierra Madre Oriental. El trabajo se desarrolló desde agosto del 2012 a diciembre del 2020.
Métodos: Se hizo una búsqueda exhaustiva de información en diversas fuentes como herbarios, bases de datos, trabajos florísticos y monografías. Para cada especie, se registró la vegetación, afinidad geográfica del género y endemismo.
Resultados: Se registran 6,981 especies de las cuales 1,542 son endémicas. Las familias más ricas en especies son Asteraceae (1,000 especies), Fabaceae (495), Cactaceae (365) y Poaceae (328). Los bosques templados registran el mayor número de especies (2,906). Querétaro fue el estado con más especies (2,803), seguido de Coahuila (2,710) y Nuevo León (2,406). La Sierra Madre Oriental comprende una mayor cantidad de especies con géneros de afinidad geográfica boreal (2,742), seguidas por especies de afinidad tropical (2,020), especies endémicas de México (1,227), cosmopolitas (803) y de los desiertos del mundo (189).
Conclusiones: La Sierra Madre Oriental alberga más de la cuarta parte de la flora vascular y un 13 % de las plantas endémicas del país. Es un área que reúne géneros de diferentes afinidades geográficas en su mayoría boreales, seguidos de tropicales y endémicos.
Salvia huastecana is described and illustrated as a new species. It is known from the municipality of Xilitla, San Luis Potosí, Mexico. This taxon belongs to Salvia sect. Angulatae, is similar to S. albiflora and S. roscida but it can be distinguished by a higher number of flowers per verticillaster (9−12), longer caducous bracts with long caudate apex, hirsute calyx with erect trichomes and white corolla, sometimes with the upper lip and margins of the lateral lobes of the lower lip light blue stained. Photographs of living plants and the illustration of the new species are provided.
Clinopodium nepeta is reported for the first time from Mexico as a naturalized plant based on two populations located in Oaxaca and San Luis Potosí. This is a variable species broadly cultivated in several countries as culinary, medicinal and ornamental plant. However, it has not been extensively grown in Mexico. We present a description of the species in the country in order to facilitate its identification and avoid possible confusion with native species of Clinopodium or Hedeoma.
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