What is present in Selaginella stem?

What is present in Selaginella stem?

Note: The stem of Selaginella is shaped like a vascular stele which is protostele. Xylem is available in the middle and is encircled by phloem and phloem is encircled by pericycle. Pith is missing. Trabeculae are available which are tube loved structures and are adjusted endodermal cells with casparian strips.

Which layer in internal structure of Selaginella stem is Trabeculated?

Option B: Trabeculae in Selaginella stem are a modified form of endodermal cells. Before generation of a gap between stele and cortex, these are known as endodermal cells Hence Option B is correct.

What stele is found in Selaginella stem?

protostele
The most primitive type of stele found in Selaginella is presumably the protostele of S. spinosa. The creeping axis of this species contains an endarch and the erect stem an exarch protostele.

What type of vascular arrangement is characteristic of the stem of Selaginella?

S. wallacei stems are characterized by a simple stele consisting of a single vascular segment (Fig. 2d).

What are the characteristics of selaginella?

Features of Selaginella (With Diagram)

• Plant body is sporophytic and the sporophyte is evergreen and perennial.
• Most of the species are prostrate but Selaginella trachyphylla is sub-erect and S.
• Size of the sporophyte ranges from few centimetres to several feet in different species.

How are the xylem and phloem arranged in selaginella?

The xylem core is surrounded by the phloem. Outside the phloem is the pericycle. It is composed of single layer of parenchymatous cells. The stele is separated from the cortex by a wide,air space.

Is the types of Protostele?

There are three basic types of protostele: haplostele (FIG. 7.32), actinostele, and plectostele (FIG. 7.33). In a haplostele, the xylem is circular in cross section or cylindrical in three dimensions; phloem is immediately outside the xylem.

Which xylem element is absent in Selaginella stem?

Xylem is usually made of tracheids. Vessels are completely absent. Xylem is surrounded on all sides by phloem which Page 3 consists of sieve cells and phloem parenchyma.

What is Rhizophore Selaginella?

feature of Selaginella is the rhizophore, a proplike structure that originates at a point of branching and that forks dichotomously after making contact with the soil or a hard surface. Rhizophores are most readily seen in clambering species.

Which of the following structure does occur in Selaginella?

Selaginella produces two types of spores—megaspores and microspores. The dimorphic condition of the spores is known as heterospory. In between the sporophyll and sporangium is present a small membranous structure known as ligule i.e., the sporophyll is similar to a vegetative leaf.

Which of the following structure does not occur in Selaginella?

Which of the following does not belong to Selaginella.

How does Selaginella look like?

Selaginella Uncinata It is often referred to as Peacock Spikemoss thanks to the bright iridescent, blue-green color of its leaves. The leaves are oblong in shape and appear paper-like and very delicate. They grow in a trailing or creeping direction but also grow up to about 2-3 inches in height.