Are Psilotum Homosporous or heterosporous?
homosporous
Psilotum is fern-like vascular plants, also known as whisk ferns. Most of them are homosporous, while some may be heterosporous.
Is Psilotum a sporophyte?
Sporophyte: The plant body of Psilotum is sporophytic branched rhizome system and dichotomously branched, slender, upright, green aerial systems (Fig. 7.11 A) that bears small appendages and synangia (singular: synangium).
How does Psilotum reproduce?
Germinate and give rise to a new plant of Psilotum. The sporophyte reproduces asexually by the formation of spores. Spores are produce in special tri-lobed structure called synangia. At maturity, many of the dichotomously branched aerial shoots become fertile and produce tri-locular sporangia known as synangia.
Is Psilotum a Lycophyte?
Psilotum is a genus of fern-like vascular plants. It is one of two genera in the family Psilotaceae commonly known as whisk ferns, the other being Tmesipteris….
| Psilotum | |
|---|---|
| Division: | Polypodiophyta |
| Class: | Polypodiopsida |
| Order: | Psilotales |
| Family: | Psilotaceae |
Are horsetails Homosporous or heterosporous?
LAND PLANTS The only extant genus, Equisetum (Equisetaceae) is herbaceous and homosporous. It has very small leaves that are more or less fused to form a dentiform leaf sheath at the node.
Is the gametophyte of Psilotum is photosynthetic?
Spores are reniform and monolete. Gametophytes are non-photosynthetic, cylindrical, saprophytic, and mycorrhizal; sperm are multiflagellate. The Psilotaceae are distributed worldwide in tropical or warm temperate regions. The two genera are: Psilotum (2–3 spp., tropical and warm regions worldwide) and Tmesipteris (ca.
Are horsetails Homosporous or Heterosporous?
Why Psilotum is called primitive?
This is primarily because psilophytes are the only living vascular plants to lack both roots and leaves. Though they have been considered “primitive,” recent developmental and molecular evidence suggests that the group may actually be reduced from fern-like ancestors.
Where is Psilotum usually found?
Psilotum nudum, one of two species in the genus Psilotum, is widely distributed across tropical and sub-tropical areas of the Americas, Africa, Asia and Australasia, with a small, endangered population found in southern Spain.
Does Psilotum have xylem and phloem?
The Psilotum Rhizome has the most simple kind of tissue organization with Xylem at the center, surrounded by Phloem, Endodermis, Ground Tissue and Epidermis.
Are club mosses sporophyte?
Like all plants, clubmosses exhibit alternation of generations. The group has a relatively large sporophyte and hard-to-find gametophyte that is small, uncommon and subterranean. The gametophyte depends upon an association with fungi to obtain carbohydrates.
Do Psilotum have Strobili?
The stem contains a single vascular trace and a central canal, surrounded by smaller cavities ans bands of cells giving strength. At the top of the fertile stem a conus-shaped strobilus is formed from rings of sporangiophores. These consist of stalks covered with a scale that protects the sporangia.
What is the sporophyte of Psilotum nudum?
The sporophyte as well as gametophyte of Psilotum (e.g., P. nudum) propagate vegetatively through the production of Gemmae (Fig. 7.15). They are small, multicellular and ovoid structures developing on surface of rhizome (in sporophytic plant body) or prothallus (in the gametophyte).
Is the gametophyte of Psilotum homothallic?
The external resemblance of the sporophytic rhizome and gametophyte, coupled with the presence of vascular tissue in the gametophyte, supported the homologous theory on the origin of alternation of generations. The gametophytes of Psilotum are monoecious (i.e., homothallic).
What is early sporophyte development in Psilotum (a)?
Early sporophyte development in Psilotum (a). The embryo possesses a single pole of growth that points away from the foot. Growth from the apical cell of this pole produces the sporophyte axis.
Which plant in the Kingdom Psilotum DeveLop In gametophytic generation?
It has been observed that in the gametophyte of tetraploid P. nudum, the centre is occupied by xylem with annular, scalariform and reticulate tracheids, surrounded by phloem and an endo- dermis. Thus, Psilotum is the only plant in the plant kingdom where the vascular tissues develop in the gametophytic generation.