The fern genus Anogramma is characterized by the presence of annual sporophytes and tubercles that persist through dry periods. Tubercles may host embryos that develop when climatic conditions are more favorable. As information on the structure of the tubercle and sporophyte of Anogramma chaerophylla is incomplete, the objective of this work was to analyze anatomical characteristics during development and deepen knowledge of the adaptive strategies of this species. Spores were grown in-vitro and different stages of tubercle development and embryonic sporophytes were fixed in FAA, embedded in Paraplast and analyzed using light microscopy. Initially, the green gametophyte developed antheridia and archegonia in its thickened portion, where later bisexual tubercles differentiated. Embryos developed only from the archegonia located in the tubercles, with one embryo developing per tubercule. During sporophyte growth the reserves accumulated in the tubercle were consumed. Oversized cells were observed at the junction between the green gametophyte and the tubercle, suggesting a possible role in translocation of substances. The young sporophyte consisted of a short shoot and a prominent foot. The placenta comprised the foot cells and the adjacent tubercle cells. The first leaves protruded soon and developed early as photosynthetic organs. Sporophytes remained attached to the tubercles until advanced stages of development. Vegetative propagation was documented in smaller tubercles that did not develop gametangia. Because few sporophytes were observed in vivo, it is likely that natural populations are maintained through vegetative propagation of the gametophyte until favorable conditions encourage development of sporophytes.

Habitat disturbance is thought to be an important determinant of juvenile club moss population occurrence, yet the few exploratory studies on juvenile club moss populations failed to address the relationship of subterranean gametophytes with incipient sporophytes and aboveground vegetation. Understanding how vegetation influences the development of the juvenile club moss population is crucial for establishing protection for these archaic plants. We used non-metric multidimensional scaling to observe vegetation differences in nine sites with juvenile club moss populations. The vegetation change over a four-year period in a dry pine forest site with a juvenile club moss (Lycopodiaceae) population and nine additional sites used for gametophyte search were analyzed. Sites with emerging juvenile club moss populations in dry pine forests included the following characteristics: 1) vegetation composition stability; 2) no tree canopy shading; and 3) the presence of Deschampsia flexuosa (L.) Trin. Other probable factors that might affect juvenile club moss population occurrence in dry pine forests are discussed.

Leaf mass per area (LMA) is one of the key features that correlates with the ecological performance both of seed plants and ferns. For ferns LMA is at the lower end of the range for seed plants and increases with leaf longevity. Data concerning morphological and anatomical traits of ferns and their relationship with LMA are quite limited. The objectives of this study were to (1) break down LMA into anatomical components; and (2) analyze the trade-offs between anatomical and morphological leaf traits, which determine LMA variations for three evergreen ferns. Seven morphological and 16 anatomical leaf traits of Polystichum setiferum, Polypodium interjectum and Asplenium scolopendrium growing outdoors in the Botanical Garden of Rome were analyzed using light microscopy. LMA was not significantly different between the considered species (4.55±0.55, 4.34±0.47, 4.28±0.41 mg cm⁻² respectively) and it was in the range of other evergreen fern species. The morphological and anatomical structure of all species was significantly different and reflected environmental adaptation of species to their natural habitats. In particular, total lamina thickness was163±16.1 μm (P. setiferum), 244±33.7 μm (P. interjectum) and 336±32.2 μm (A. scolopendrium); leaf tissues density ranged from 127±16.9 mg cm⁻³ (A. scolopendrium) to 277±37.1 mg cm⁻³ (P. setiferum); intercellular air space varied between 23.2±2.07% (P. interjectum) and 41.8±1.61% (A. scolopendrium). The overall results highlight that LMA is an integral feature that can be obtained by different anatomical structure.