Aniceto Mendoza-Ruiz

Developmental gametophyte morphology of seven species of Thelypteris subg. Cyclosorus (Thelypteridaceae)

The morphogenesis of the sexual phase of seven species of Thelypteris subg. Cyclosorus (Thelypteridaceae) is described and compared. Spores of all species are monolete, ellipsoid and have positive photoblastism. They have Vittaria-type germination, germinal filaments are short and uniseriate, and Aspidium-type development. Adult gametophytes are spatulate-cordiform, and have wide wings with numerous glandular, marginal and superficial hairs. Antheridia have a narrow or widened basal cell, an undivided annular cell, and an opercular cell; antherozoids are liberated through three mechanisms. Archegonia have short necks and four triangular cells on the necks mouth. The sporophytes first leaf is lobed, with open dichotomous veins, glandular hairs similar to those of the gametophyte, and anomocytic stomata. Differences observed between the studied species are: spore size; ornamentation of the perispore; germination and emergence periods; size of hairs; developmental period of gametangia; and antherozoid liberation mechanisms through total detachment of the operculum, partial detachment of the operculum, and development of an apical pore through tearing of the operculum. These taxonomically valuable characters, combined with the sporophyte characteristics, can be useful tools in the identification of the species studied to the subg. Cyclosorus.

A Contribution to the Gametophyte Morphology and Development in Several Species of Thelypteris, Thelypteridaceae

Abstract A contribution to the study of the gametophytes morphology and development of some species of Thelypteris Schmidel (Thelypteridaceae). The development and morphology of the sexual phase of five species of the Thelypteridaceae family is described and compared. Spores were sown in Thompson medium with agar, germination occurred after 11 days; all spores of the species studied are monolete, ellipsoid with a pleated perine, brown to dark brown; the germination pattern is Vittaria type and the prothallial development is Aspidium type. Gametangia are of the common type of the leptosporangiate ferns. Sporophytes in Thelypteris reptans var. reptans and T. tetragona appear 90–285 days after sowing; T. dissimulans, T. piedrensis and T. oviedoae did not develop any sporophytes. The sexual phase of these species has many morphological characteristics in common with species of the Old and New Worlds.

Observations of the spore, gametophyte and young sporophyte of Pteridium caudatum (L.) Maxon using scanning electron microscopy.

This paper describes the development of the sexual phase of the invasive fern, Pteridium caudatum, from spore germination to young sporophyte formation. Spores samples for gametophyte cultures were taken from various sporophytes and then sown on mineral agar with Thompsons media. Gametophytes were maintained under fluorescent light on a 12h light, 12h dark cycle at 24-25°C. Developmental phases were fixed in FAA-sucrose solution and processed for observation with the scanning electron microscope. Spores are trilete and germination takes place on the second day after sowing; germination is of the Vittaria-type. Adiantum-type prothallial development was observed. The differentiation of a two-dimensional thallus begins 5 days after germination maturation of adult gametophytes occurs about 30 days after sowing. Adult gametophytes are heart-shaped, bisexual and glabrous. Antheridia are formed by three cells: basal, annular and opercular cell with a pore. Archegonia have a neck of 4-cells. The young sporophyte becomes visible within 8 weeks after spores are sown. The taxonomic significance of the gametophyte morphology is discussed.

Gametophyte morphology of Platycerium andinum Baker and Platycerium wandae Racif.

This paper describes the morphology of the sexual phase and spores of Platycerium andinum and Platycerium wandae. Spores were sown in Thompsons media and the cultures were kept at 24-25 degrees C, with 12h light/darkness photoperiod. Developmental phases were fixed in FAA and processed for observation with the scanning electron microscope. Spores of both species are monolete; Vittaria-type germination and Aspidium-type prothallial development were observed. In the phase of development, the gametophytes develop unicellular secretory and as they mature, develop bifurcated or branched pluricellular trichomes, both in the cushion and near the meristematic zone. Adult gametophytes in culture are cordiform-spatulate to cordiform-reniform, most are unisexual and a few are bisexual. Gametangia belong to the leptosporangiate fern type. Archegonial morphology is uniform, with an elongate, thin neck curved toward the base of the gametophyte. Antheridia have a basal cell, an annular cell and an undivided opercular cell. Three hundred days after the spores were sown, sporophytes still had not developed. In both species, some spores germinate inside the sporangial capsule (intra-sporangial germination). We provide new information on morphogenesis in the genus Platycerium.

A Pluviometric Fern Spore, Fungal Spore, and Pollen Trap

Abstract 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.

Gametophyte Morphology in Three Mexican Species of Bolbitis (Lomariopsidaceae)

ABSTRACT The development of gametophytes in Bolbitis bernoullii, B. portoricensis and B. umbrosa (Lomariopsidaceae) is described and compared. Spores are monolete, ellipsoid with prominent winged perispore. Germination is of the Vittaria type and the prothallial development is of the Drynaria type. Collenchyma-like thickenings at the corners of the wing cells were not observed. Adult gametophytes are cordate with scarce marginal hairs near the shallow notch. Gametangia are of the common type found in homosporous leptosporangiate ferns. Bolbitis portoricensis develops the first leaf of the sporophyte after 6 to 8 months, with polocytic stomata. In B. portoricensis, vegetative propagation is present in old thalli 6 to 8 months after cultivation.

Gametophyte development in Mexican species of Gleicheniaceae

In Mexico, the Gleicheniaceae family is represented by different species such as Dicranopteris flexuosa, Diplopterygium bancroftii, Gleichenella pectinata, Sticherus bifidus, S. brevipubis, S. palmatus and S. underwoodianus. Currently, few studies have described the gametophytes of some species in this family, and our objective was to contribute to the knowledge, and to describe and compare different aspects of their germination, gametophyte development, and to determine if the prothallus characters are useful for taxonomic delimitations in the group. For this purpose, specimens and spores of each taxon were collected in the field, spores were sown in Petri dishes containing agar and Thompson nutrient medium, and grown in a plant growing chamber under controlled conditions of light (12 hr light/darkness), (50 %) humidity, and temperature (18 °C night, 25 °C day). Additionally, observations of fresh materials were made and photomicrographs were taken using both optical and scanning electron microscopes. Our observations allowed distinguishing two types of germination Gleichenia and Cyathea; and three types of prothallial development Marattia, Osmunda and Drynaria. Gametangia presented more than three cells, and this is considered a primitive feature by other authors. As some variations in the germination type were observed and have not previously been reported in the literature for this family, and because of the heterogenity in the patterns of the prothallial cell development, and gametangia of more than four cells, it is important to broaden the study to other species, in order to determine the taxonomic value of the morphological characters of the gametophyte, as well as to determine if these variations are present in other species of the family.

Ethnobotany of Lycophyta and Polypodiophyta in Priority Terrestrial Regions of Oaxaca, Mexico

Abstract Lycophyta and Polypodiophyta have been used by humans worldwide since ancient times, yet little has been documented. This paper analyzes and discusses the different uses of these plants in three Priority Terrestrial Regions (PTR) of conservation in the state of Oaxaca in Mexico. Our objectives were to: 1) document the traditional knowledge and uses of Lycophyta and Polypodiophyta among ethnic and mestizo groups; 2) analyze the variation in the use of taxa among these ethnic and mestizo groups, in terms of altitudinal distribution and type of vegetation in habitats supporting these species. Fifty species and two varieties of useful Lycophyta and Polypodiophyta from 29 genera and 15 families, were recorded. Mazatecs, Zapotecs, and Mixes are the ethnic groups with the greatest number of records of useful species from these taxonomic groups. More than 68% of such species are recognized with common names in the local languages. There are two conditions of useful plants: 1) among species used by at least four ethnic groups, how do the uses vary from two to four; 2) related to species with at least four categories of use, which are used by few ethnic groups. More than half of the species are named in at least one language, which reinforces the fact that species are recognized, valued, and important in peoples daily lives, including traditional ceremonies, beliefs. Eight categories of use were documented, with medicinal, ornamental, and handcraft being the most represented. 80% of the useful Lycophyta and Polypodiophyta were distributed above 1000 masl, mainly in montane cloud forest, Quercus forest and Quercus-Pinus forest.