Question

describe the life history of psilotum with suitable sketches​

Answer 1

Answer:

Absence of roots and sporophytic generation bears rhizoids. 4. Sporangia multilayered, in rare instance are terminal. The above similarities suggest that Psilotales (Psilotum and Tmesipteris) is the most primitive extant group among the vascular plants.Polystele: Generally in a protostele, the stem has a single stele in the centre. But in Selaginella, the stem axis has several steles in parallel arrangement (di-stelic or polystelic). Each stele is a protostele with xylem core surrounded by phloem with pericycle and endodermis.