Family Description: Aspleniaceae, commonly known as the spleenwort family, is a group of ferns within the order Polypodiales. It includes around 700 species, primarily in the genus Asplenium, with a global distribution spanning tropical to temperate regions. Members are typically terrestrial or epilithic, and some are epiphytic, thriving in moist, shaded habitats.
Plants grow from creeping or erect rhizomes, often covered with clathrate (lattice-like) scales. Fronds are monomorphic and range from entire to 4-pinnate, with a wide variety of shapes and sizes. Leaf stalks (petioles) usually contain two vascular bundles that unite into an X-shape toward the apex.
A defining feature of the family is the elongated sori, which are typically arranged along one side of the veins and covered by a narrow, flap-like indusium. Sporangia are stalked, with a vertical annulus, and produce bilateral, bean-shaped spores.
Aspleniaceae is notable for its morphological diversity and ecological adaptability. Some species form natural hybrids, and molecular studies have revealed complex evolutionary relationships within the group.
Maidenhair Spleenwort Fern, Common Spleenwort Fern
Felċi rqiqa
All year
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DRYOPTERIDACEAE Herter
( Buckler fern Family )
Subfamalies: Dryopteridoideae; Elaphoglossoideae
Family Description: Dryopteridaceae, commonly known as the wood fern or shield fern family, is a large and cosmopolitan group of leptosporangiate ferns in the order Polypodiales. It includes about 40–50 genera and approximately 1,700 species, with a global distribution but greatest diversity in temperate regions and tropical mountains.
These ferns are typically terrestrial or epipetric (growing on rocks), though some are epiphytic or hemiepiphytic. They often grow from creeping, ascending, or erect rhizomes, which are covered in non-clathrate scales. The fronds are usually monomorphic (uniform in shape), though some species exhibit dimorphic fronds with distinct fertile and sterile forms. Leaf blades are often pinnate to decompound, and the venation may be free or anastomosing, sometimes forming areoles with or without included veinlets.
A key feature of Dryopteridaceae is the presence of round sori (clusters of sporangia) on the underside of the fronds, typically protected by a kidney-shaped (reniform) or peltate indusium. The sporangia are stalked, with a vertical annulus, and produce monolete, reniform spores. These spores are often bean-shaped and may have a winged or ornamented perine. Many species are cultivated as ornamentals, and some have been used in traditional medicine or veterinary applications. Notable genera include: Dryopteris (shield ferns); Polystichum (holly ferns); Elaphoglossum (tongue ferns); Ctenitis and Arachniodes
Family Description: Equisetaceae, comprising the sole extant genus Equisetum, are perennial, rhizomatous vascular plants notable for their ancient lineage and distinctive morphology. Stems are jointed, hollow, and ribbed, arising from extensive underground rhizomes that allow clonal propagation. The aerial shoots may be green and photosynthetic or unbranched and non-photosynthetic, depending on the species. Leaves are highly reduced, scale-like, and arranged in whorls at stem nodes, fused at their bases into a sheath.
Reproduction is via spores produced in strobili, borne terminally on fertile stems. These spores possess elaters—hygroscopic appendages that assist in dispersal. Unlike most modern ferns, Equisetum possesses silica-rich epidermal tissues, lending a gritty texture to stems. Growth is guided by apical meristems with intercalary growth zones that contribute to elongation.
Ecologically, horsetails favor moist, often riparian habitats, though some tolerate disturbed sites. The genus represents an evolutionary lineage that once dominated Carboniferous forests in tree-sized forms, now reduced to herbaceous survivors with remarkable structural adaptations. Despite their modest appearance today, Equisetum species remain evolutionarily significant as living fossils of a once-diverse clade.
Family Description: Isoetaceae, commonly known as the quillwort family, is a small but ancient group of vascular plants within the division Lycopodiophyta. The family is represented today by a single extant genus, Isoetes, comprising about 200 species found in freshwater habitats worldwide, particularly in lakes, ponds, and marshy soils.
Morphologically, Isoetes species are perennial, heterosporous lycophytes with a distinctive grass-like appearance. They grow from a short, lobed corm—a subterranean stem that anchors the plant and stores nutrients. From this corm arise numerous narrow, quill-like leaves, which are spirally arranged and hollow, each containing four longitudinal air canals. At the base of each leaf is a sporangium, partially or fully covered by a thin membranous tissue called the velum.
Reproduction is via megaspores and microspores, produced in separate sporangia on the same plant. This heterospory is a key evolutionary trait linking Isoetaceae to seed plants. The spores are released into water, where gametophytes develop and fertilization occurs.
Despite their modest appearance, Isoetaceae are considered living fossils, with a lineage dating back to the Paleozoic era. Fossil relatives once formed part of vast swamp forests, and today’s species retain many primitive features, offering valuable insights into early vascular plant evolution.
Family Description: Polypodiaceae is a diverse family of ferns within the order Polypodiales, predominantly found in tropical and subtropical regions—with several species extending into temperate habitats. Depending on the classification system, the family is circumscribed to include roughly 56–65 genera and an estimated 1,200–1,650 species. Some broader treatments of the group incorporate additional taxa formerly separated into families such as Grammitidaceae, resulting in what is sometimes termed a “megafamily” of polypod ferns.
Members of Polypodiaceae are most commonly epiphytic, often colonizing the trunks and branches of trees in humid forests, although terrestrial representatives occur as well. They typically exhibit creeping or climbing rhizomes densely covered with scales, which help secure the plants on their substrates. The fronds are usually pinnate or lobed, and their undersides carry clusters of sporangia arranged in sori. Notably, these sori generally lack a well-developed protective indusium; if present, any covering is more often formed by modified peltate scales rather than a continuous membrane. Such reproductive and vegetative traits are key to both the ecological success and the taxonomic evaluation of this fascinating fern family.
Beyond their ecological roles in forming integral components of forest canopies and understories, species in Polypodiaceae are also valued in horticulture for their aesthetic fronds and adaptability to a range of growing conditions.
Family Description: Pteridaceae is a large and diverse family of ferns in the order Polypodiales, comprising roughly 1,150 recognized species distributed among about 45 genera (though numbers may vary with different taxonomic treatments). Members of this family exhibit a remarkable range of ecological adaptations, thriving in habitats as varied as tropical rainforests, seasonally dry areas, rock crevices, and even some semi‐arid environments.
Characteristic features of Pteridaceae include creeping or erect rhizomes and typically compound fronds that are either pinnate or bipinnate. One diagnostic trait is the arrangement of sporangia: they are usually borne along the margins of the leaf (a feature known as marginal sori) and are often covered by a false indusium—a protective flap formed by the reflexed margins of the frond, rather than a true, dedicated indusium. The spores themselves are mostly tetrahedral in shape and are dispersed by wind, contributing to the wide distribution of these ferns.
Taxonomically, the family has historically been divided into several distinct groups—such as the adiantoid, cheilanthoid, pteridoid, and hemionitidoid ferns—that some botanists have suggested merit recognition as separate families. However, modern molecular studies tend to group these clades within a broadly defined Pteridaceae, even as ongoing research continues to refine our understanding of their evolutionary relationships.
Family Description: Salviniaceae is a family of heterosporous aquatic ferns in the order Salviniales, comprising two genera—Azolla and Salvinia—and totaling around 20 species. These ferns are specially adapted to a floating lifestyle in tropical and subtropical regions. They exhibit highly modified, often bilobed leaves that facilitate both aerial photosynthesis and submerged functions; for example, some species display one green, photosynthetic lobe on the upper surface and a more delicate, often translucent or reduced lower lobe.
A key feature of this family is heterospory, meaning that they produce two different types of spores—megaspores and microspores—as part of their reproductive cycle. Their reproductive organs are enclosed in hardened sporocarps, which provide protection and aid in the controlled release of spores when environmental conditions are favorable. In addition to these characteristics, there is an intriguing ecological partnership in some Azolla species, which form symbiotic relationships with nitrogen-fixing cyanobacteria. This association not only enhances the fern’s growth in nutrient-poor waters but has also found practical applications in agriculture, notably in rice paddies where the ferns contribute to natural nitrogen enrichment.
This blend of reproductive innovation, specialized morphology, and ecological significance makes Salviniaceae a fascinating example of adaptation to aquatic environments.
Family Description: Selaginellaceae is a family of lycophytes that is represented solely by the genus Selaginella, which includes over 700 recognized species distributed worldwide. These plants are often referred to as spikemosses and are distinguished by their scale-like microphylls that typically bear a small, cup-like structure known as a ligule. Unlike clubmosses in Lycopodiaceae, members of Selaginellaceae are heterosporous, producing two distinct sizes of spores—megaspores and microspores—which is a key adaptation in their reproductive cycle.
Many species in this family exhibit striking ecological adaptations; for example, Selaginella lepidophylla, commonly called the resurrection plant, can survive extended periods of drought by curling into a tight ball and reviving rapidly when moisture returns. Fossil evidence suggests that the lineage of modern Selaginella extends back over 300 million years to the Late Carboniferous, underscoring its ancient origin and remarkable evolutionary persistence.
