Q.59 A stele which does NOT contain a central pith is called as:

1. Solenostele
2. Dictyostele
3. Protostele
4. Siphonostele

Stele Without Central Pith

A stele is the central vascular cylinder in plant stems and roots, and its types differ based on pith presence and structure. This article covers Q.59’s correct answer with breakdowns of all options for plant anatomy learners.

Correct Answer

The correct option is 3. Protostele. It features a solid core of xylem surrounded by phloem without any central pith.

Option (1): Solenostele

Solenostele is a siphonostele variant with a continuous vascular cylinder around a central pith, interrupted only by leaf gaps. It always contains pith.

Option (2): Dictyostele

Dictyostele, an advanced siphonostele, has overlapping leaf gaps that fragment the vascular tissue into a net-like structure around pith. Central pith is present.

Option (3): Protostele

Protostele is the primitive type with a solid central xylem mass (no pith) fully enclosed by phloem. Examples include roots and lycopod stems.

Option (4): Siphonostele

Siphonostele has a ring of vascular tissue surrounding a central pith, with possible leaf gaps. Pith distinguishes it from protostele.