What are the primitive characteristics of Psilotum?

The unusual features of Psilotum that suggest an affinity with early vascular plants include dichotomously branching sporophytes, aerial stems arising from horizontal rhizomes, a simple vascular cylinder, homosporous and terminal eusporangia and a lack of roots.

1. Is Psilotum primitive?
2. What are the characteristics of whisk fern?
3. What generation is Psilotum?
4. What is the nature of stele in Psilotum?
5. Where is Psilotum usually found?
6. Why Psilotum is considered as primitive?
7. Why is Psilotum a living fossil?
8. What phylum is Psilotum?
9. Does Psilotum have xylem phloem?
10. How do you grow Psilotum?
11. How do Psilotum reproduce?
12. What is Synangium in Psilotum?
13. Does Psilotum have lignin?
14. Where does photosynthesis occur in Psilotum?

Is Psilotum primitive?

Psilotum (whisk ferns; family Psilotaceae) A genus of very primitive vascular plants without true roots, and with the spore capsules borne in fused triads on the upper parts of the forking stems, in the axils of tiny scales. There are no real leaves, but the ridged stems are green, and act as photosynthetic organs.

What are the characteristics of whisk fern?

A whisk fern has water- and food-conducting tissues but lacks true leaves and roots. Photosynthesis occurs in the aerial stems, and water and mineral absorption occurs in the horizontal underground rootlike stems (rhizomes), which receive water and nutrients from fungi through a mycorrhizal association.

What generation is Psilotum?

Thus, Psilotum is the only plant in the plant kingdom where the vascular tissues develop in the gametophytic generation.

What is the nature of stele in Psilotum?

The stele is protostelic and is surrounded by a typical endodermis which is followed by a layer of pericycle. The shape of the xylem varies with the diameter of the axis. Usually it is circular in outline. The xylem is exarch and is surrounded by phloem.

Where is Psilotum usually found?

Psilotum spp. are commonly found in warm moist regions in the southern United States. 2.3 Describe several distinguishing features of phylum Psilotophyta. The small plant has no leaves or roots and a dichotomously branching green stem with small scales that bears bright yellow synangia on lateral branches.

Why Psilotum is considered as primitive?

The primitive nature of the whisk fern is underscored by its having flagellated sperm, unlike the more advanced flowering plants, the angiosperms. ... Because Psilotum is without leaves, the interior parts of the stem conduct food and water, known as the vascular cylinder.

Why is Psilotum a living fossil?

Psilotum is the only living vascular plant to lack both leaves and roots so they are called living fossils.

What phylum is Psilotum?

Seedless vascular plants include four phyla with living representatives: phylum Psilophyta (including only two genera, Psilotum and Tmesipteris), phylum Lycophyta (about 1000 species, including the club mosses and the genera Selaginella and Isoetes), phylum Sphenophyta (the horsetails in the genus Equisetum, ...

Does Psilotum have xylem 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.

How do you grow Psilotum?

P. nudum thrives best in partial shade and can tolerate more sunny locations, and prefers moist but well-drained soil. Plants will grow in full shade but are somewhat reduced in density, extent and size. It also is commonly found growing as an epiphyte throughout Central Florida.

How do 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.

What is Synangium in Psilotum?

Synangium is a trilocular or three chambered, spore bearing structure in Psilotum. It is considered as a fusion product of three sporangia. Location: axils of foliar leaves on aerial shoot. Synangium C.S: It consists of 3 chambers or locules.

Does Psilotum have lignin?

Psilotum nudum is one of the earliest extant vascular plant taxa that has water-conducting tissues with secondary cell walls similar to those of angiosperms, i.e., containing, in addition to cellulose, β-(1,4)-D-xylan and lignin.

Where does photosynthesis occur in Psilotum?

Psilotum stems arise from short branching ______ just beneath the surface of the ground. If Psilotum lacks leaves, where does photosynthesis occur? Photosynthesis takes place in the outer cells of the stem.