Antecedentes: Los estudios sobre los patrones de floración, sincronía floral y éxito reproductivo en cactáceas son incipientes y de muchas especies se desconoce prácticamente su biología reproductiva como ocurre con la cactácea globosa Neolloydia conoidea . Preguntas: ¿Cómo es el patrón de floración a nivel poblacional? ¿Cómo es la sincronía floral? y ¿Existe relación entre la sincronía floral y el éxito reproductivo? Especie: Neolloydia conoidea Britton & Rose (Cactaceae) Sitio de estudio y fechas: Municipio de Tolimán en Querétaro, México. Dos años de observaciones (N = 146 individuos en 2015; 142 en 2016) en una población de Neolloydia conoidea . Métodos: Censo de las flores en antesis y análisis de la fenología de floración a través de Estimadores de Densidad por Kernel (EDK) y componentes gaussianos. Determinación de la sincronía floral a través de los índices de Augspurger (SA) y de Marquis (SM) y comparación del éxito reproductivo (fruit set y seed set) por año y por pulsos. Resultados: Neolloydia conoidea presentó un patrón de floración con 5 a 6 pulsos discretos al año. La sincronía por año y por pulsos fue baja y no se correlacionó con el éxito reproductivo. Conclusiones: Neolloydia conoidea presenta un patrón de floración en pulsos con bajos niveles de sincronía. Este es el primer registro de dicha estrategia para una cactácea globosa, aunque un patrón similar ya ha sido reportado para una cactácea columnar. Sugerimos que esto podría representar una estrategia de “bet hedging” en el sitio de estudio.

Lophophora diffusa (Cactaceae) –an endangered species– known as peyote or peyote queretano– is of great ecological relevance because of its medicinal and ornamental use by native peoples and collectors. Little is known about the population of this species and no strategies exist for their use since its cultivation and usage is prohibited in Mexico. Thus, the objective of the present research is to describe population dynamics in a locality of the state of Querétaro, México. For this purpose, 380 individuals were followed through four annual and one quinquennial censuses. From these data, the population structure was determined, including the finite population growth rate (λ), stable size structure, reproductive value, relative importance of size categories and demographic processes (permanence, growth, and fecundity) for each period by using transition matrixes. Moreover, future population estimations were performed, showing scarcity of seedlings and adult plants of greater size, where λ indicates a population decline that oscillates between 2 and 20%. The most important demographic process was survival, where the adult 2 category resulted essential. The projections indicate that the population may disappear in a period of less than 50 years. Therefore, the proposal is to revise the Mexican legislation to allow a regulated cultivation with the purpose of protecting the wild populations of the species and its habitat.

Succulent plants in arid ecosystems exhibit contrasting strategies to cope with high irradiance, thermal stress, and water limitation. We evaluated spatial distribution, microhabitat use, nurse identity, and orientation beneath canopies for two threatened globose cacti from the Querétaro semi-desert (Mexico): Ariocarpus kotschoubeyanus and Lophophora diffusa. One site with high population density was selected for each species, where 10 plots were established (9 m² for A. kotschoubeyanus and 49 m² for L. diffusa). The study aims to evaluate whether species-specific recruitment patterns are associated with differential dependence on nurse-plant microhabitats under conditions of radiation and thermal stress. We hypothesized that: (1) both species exhibit aggregated spatial distributions but differ in their reliance on nurse-mediated microclimatic buffering; and (2) nurse-plant identity and orientation patterns vary between species, reflecting species-specific ecophysiological thresholds to irradiance and heat stress. Both species showed strongly aggregated spatial distributions (Hopkins index > 0.8), indicating recruitment constrained by microsite heterogeneity. However, their stress-adaptation strategies differed markedly. A. kotschoubeyanus occurred predominantly in open microsites (79%), consistent with its geophytic growth form and tolerance to high radiation and temperature extremes. In contrast, L. diffusa was strongly associated with nurse plants (78%), particularly Larrea tridentata and Bursera fagaroides, and preferentially established on eastern canopy exposures that reduce afternoon heat load. These patterns reflect species-specific ecophysiological thresholds linked to radiation tolerance and microclimatic buffering. Facilitation in globose cacti is therefore trait-mediated and context-dependent. Maintaining perennial shrub diversity is essential to preserve the microhabitats that sustain recruitment and persistence of stress-sensitive succulents under increasing climatic aridity.