Get Selaginella Strobilus

In contrast to Lycopodium, the sporophytes of all spike mosses (Selaginella) have sporophylls localized in strobili, and all species of Selaginella are heterosporous; that is, they produce spores of two sizes, the larger designated as megaspores and the smaller as microspores.

The sporangium are located in the sporophylls and the sporophylls are compactly arranged to form cones or strobili. Strobilus: All the species of Selaginella forms strobili or cones. Generally strobili occur terminally on side branches, but in some species (e.g., S.

They resemble mosses and may be frequently overlooked. Selaginella apoda has dimorphic leaves arranged in four ranks. The leaves of the lateral ranks are larger than those of the upper and lower ranks. Like other spike-mosses, the reproductive structure is a leafy, spore cone borne at the apex of the stem.

The genus Selaginella is classified in the division Lycophyta, which includes the numerous plants commonly known as clubmosses and spike mosses. Similar to their close relatives, Selaginella plants develop strobili, spike-like reproductive organs that form on fertile branches.

Cones or strobili are found in Pteridophytes, Selaginella and Equisetum.

The Longitudinal section (L.S.) of strobilus shows that it is a very simple structure. It consists of a central axis covered with spirally and densely arranged ligulate sporophylls. Each sporophyll adaxially bears a single stalked sporangium in its axis (Fig.

The Longitudinal section (L.S.) of strobilus shows that it is a very simple structure. It consists of a central axis covered with spirally and densely arranged ligulate sporophylls. Each sporophyll adaxially bears a single stalked sporangium in its axis (Fig.

Lycopodium is homosporous--all spores are roughly equal in size. Selaginella and Isoetes are heterosporous--spores are of two distinct sizes, microspores and megaspores.