Anogramma is a genus of small, delicate, annual ferns belonging to the family Pteridaceae, specifically within the subfamily Vittarioideae. These ferns are characterized by their ephemeral nature, typically completing their life cycle within a single growing season.
Characteristics
- Growth Habit: Anogramma species are generally small, terrestrial or lithophytic ferns. They are often described as "resurrection ferns" due to their ability to quickly grow and sporulate after rain, often appearing in cracks of rocks or disturbed ground.
- Fronds: The fronds are typically dimorphic, meaning they have two distinct forms. Sterile fronds are usually broader and more lobed, while fertile fronds are narrower and more erect, bearing sori (clusters of sporangia) along the veins. The sori are typically linear or oblong and lack indusia (a protective covering).
- Rhizome: They possess a very short, unbranched, erect rhizome.
- Life Cycle: As annuals, they grow from spores each year and die back after producing new spores. Their ability to rapidly complete their life cycle allows them to thrive in habitats with intermittent moisture.
Species The most widely known and recognized species within the genus is Anogramma leptophylla, commonly known as the annual fern, slender annual fern, or delicate annual fern. This species has a cosmopolitan distribution, found in tropical, subtropical, and temperate regions around the world. Other species are less commonly recognized or are sometimes considered synonyms or varieties of A. leptophylla.
Habitat and Distribution Anogramma ferns typically inhabit moist, shaded, and often rocky environments, such as cliff crevices, mossy banks, and disturbed ground. They prefer sites with some degree of shelter from direct sun and wind. Due to the wide distribution of A. leptophylla, the genus is found across many continents, including parts of Europe, Africa, Asia, Australia, and the Americas.
Etymology The name Anogramma is derived from the Greek words "ano" (upwards) and "gramma" (line), likely referring to the linear arrangement of the sori along the veins or their upward-pointing orientation on the frond.
Taxonomy
- Kingdom: Plantae
- Division: Tracheophyta
- Class: Polypodiopsida
- Order: Polypodiales
- Family: Pteridaceae
- Subfamily: Vittarioideae
- Genus: Anogramma Link