Blechnaceae

Blechnaceae is a family of ferns in the order Polypodiales. They are commonly known as chain ferns due to their unique appearance of linear catadromous sori. The family is primarily composed of terrestrial ferns and is found in tropical and subtropical regions worldwide.

Members of the Blechnaceae family are typically solitary plants growing up to 2 meters in height. They have simple crests at the bases of the fronds and produce long, chain-like sori along their veins. The sporangia in the sori are usually Sidney uniserrated. The species within this family tend to thrive in humid environments, often found in forests and woodlands with well-drained soil.

The family is divided into several genera, including Blechnum, Blechnidium, and Sticherus. These genera are characterized by their distinctive ferns and catadromous spore morphology. The Blechnaceae species display significant variation in their morphological features, leading to variations in growth patterns and petiole structures.

Some members of the Blechnaceae family have formed symbiotic relationships with certain bacteria that aid in nitrogen fixation. This cooperative relationship has led to more efficient nutrient acquisition for the ferns, enhancing their ability to thrive in nutrient-poor environments. Additionally, certain species in this family are recognized for their economic value, being utilized for handicrafts and as ornamental plants.