In certain pteridophytes, the strobilus is organized such that the sporophylls are densely packed around a central axis, mimicking the appearance of a spike inflorescence. This specific arrangement is referred to as a sporangioferous spike, where the sporangia are borne on specialized structures known as sporangiophores.

Pteridophytes are traditionally classified into four main divisions: Psilophyta, Lycophyta, Sphenophyta, and Pterophyta. These groups are distinguished based on their morphological characteristics, vascular tissue arrangement, and the nature of their leaves and reproductive structures.

In ferns like Polypodium, the sporangia are typically aggregated into clusters on the underside of the fertile fronds. These clusters are technically referred to as sori (singular: sorus). The sorus may be naked or covered by a protective membrane called an indusium, depending on the specific species and its evolutionary adaptations for spore protection and dispersal.

The sporophyte of Polypodium exhibits a well-differentiated plant body. It consists of a creeping underground stem known as a rhizome, which produces adventitious roots for anchorage and absorption. Additionally, it bears fronds, which are the leaves responsible for photosynthesis and, in fertile fronds, the production of spores within sori. Thus, all listed parts are integral to its structure.

Megaphylls are large leaves that possess a complex, branched vascular system. Unlike microphylls, which have a single vein, megaphylls evolved through the modification of branch systems, resulting in a broad leaf blade (lamina) supported by a network of veins. This structure is typical of most ferns and seed plants, providing a larger surface area for photosynthesis.

Psilotum is a genus of whisk ferns that lacks true roots and leaves. Its aerial stems are dichotomously branched and green, giving the plant a distinct, small, shrub-like appearance in its natural habitat.

In classical botanical classification systems, the class Pteropsida (Filicopsida) is often divided into four distinct subclasses: Primofilices, Eusporangiatae, Leptosporangiatae, and Hydropteridae. These subclasses are distinguished primarily by their sporangial development, vascular anatomy, and reproductive strategies, reflecting the evolutionary diversity within the fern lineage.

Marsilea is a heterosporous water fern. In certain conditions, it can exhibit parthenogenesis, where the egg cell develops into a new sporophyte without undergoing fertilization. This is a specialized reproductive strategy observed in some aquatic Pteridophytes.

Polypodium belongs to the order Filicales, which includes the majority of modern homosporous ferns. Pteropsida is a higher-level division, while Polypodiaceae is the family. The order Filicales is characterized by the presence of leptosporangiate sporangia, which are typically organized into sori on the underside of the fronds.

In Pteridophytes, the female sex organ is called the archegonium (often spelled archigonia in plural contexts). It is a flask-shaped structure that contains the female gamete, or egg, and provides a protected environment for fertilization to occur.