Although rain is the most important agent in airborne biological particle deposition most of the current sampling traps retain palynomorphs (fern spore, fungal spore, pollen, among others) but are unable to measure precipitation. The objectives of this study are to present a new simple pluviometric/gravimetric spore/pollen trap and propose a spore/pollen-density rain method, based on the particle frequency and sampling area, which would facilitate ecological inferences about rainfall and Biological Airborne Particle (BAP) deposition, so as to avoid the overrepresentation of the percentage and diverse aerobiological methods. Relative to other spore traps, our proposed trap is simple to build, easy to mount in the field, easy to carry, maintenance free, and requires no energy source. In addition, our trap records rainfall volume, and the quantity of spores captured can be expressed in terms of area-density (particle m⁻²). The rainfall measured with the trap had no significant differences with the precipitation volume obtained from the pluviometer of the Automatic Meteorological Station at Zacualtipán, Hidalgo, Mexico.

Isoëtes viridimontana is described and illustrated. Plants of this species are currently known only from Haystack Pond, a small, acidic, oligotrophic lake in south central Vermont. Isoëtes viridimontana is distinguished from other Isoëtes species in northeastern North America by its size (less than 5 cm high) and granulate to rugulate megaspore texture.

Polypodium gyroflexum has been a forgotten name since 1940. It is, in fact, an earlier name to a fern recently known as Pleopeltis repanda. Here, I provide the new combination, lectotypification, a detailed characterization, and illustrations for Pleopeltis gyroflexa, comb. nov., plus the synonymization of Pleopeltis repanda. Pleopeltis gyroflexa is known from two populations located ca. 2500–3000 km from each other, and they show some slight morphological differences. The gap between them comprises Amazon forest, the Amazon River, croplands, disturbed areas, and semi-desert vegetation (Caatinga). A vegetation map with their distribution data is also provided.