Does Psilotum have dichotomous branching?
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.
What type of branching does Psilotum have?
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).
What is the sub division of Psilotum?
Data Quality Indicators:
| Subdivision | Polypodiophytina |
| Class | Polypodiopsida – leptosporangiate ferns |
| Subclass | Ophioglossidae |
| Order | Psilotales |
| Family | Psilotaceae |
What is Synangium 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.
What shows dichotomous branching?
(D)pteridophytes. Hint: The division of the apical meristem into two independently functioning axes is defined as dichotomous branching. This kind of branching generally occurs in non-vascular and non-seed vascular plants, whereas in seed plants it illustrates a primary growth form only in some taxa.
What do you mean by dichotomous branching?
The division of the apical meristem into two independently functioning axes is defined as dichotomous branching. This type of branching typically occurs in non-vascular and non-seed vascular plants, whereas in seed plants it presents a primary growth form only in several taxa.
Do ferns have sporangium?
In ferns, spores are contained within cases called sporangia that are located on the underside of leaves. Examples of sori and arrangements of sporangia in various species of ferns.
What is Monopodial and dichotomous branching?
Monopodial branching occurs when the terminal bud continues to grow as a central leader shoot and the lateral branches remain subordinate—e.g., beech trees (Fagus; Fagaceae). Sympodial branching occurs when the terminal bud ceases to grow (usually because a terminal flower has formed) and an axillary…
What is the phylogeny of the Psilotum plant?
Phylogeny. Though several species have been reported in Psilotum, all of them usually fall into two well defined species, viz., P. nudum (P. triquertum) and P.flaccidum (P. complanatum). The earlier reports of the existence of several species is probably due to the polymorphic nature of the sporophyte.
How big are the spores of a Psilotum?
The synangium splits open along this line liberating the spores. Structure of the spore: Spores vary in shape from bilateral to tetrahedral type. Their average size is 0.065 x 0.032 mm. Germination of the Spore and Development of Gametophyte:
How big are the lobes of a Psilotum?
The sporangia are fused with one another, and such group of sporangia is known as synangium. Each mature synangium is 2-3 mm wide, 3-lobbed and each lobe contains a spore sac, in which numerous spores are present. Psilotum is homosporous, i.e., it produces only one type of spores.
How does vegetative reproduction take place in Psilotum?
1. Vegetative Reproduction:- Vegetative reproduction in Psilotum takes place by the formation of gemmae. The gemmae are developed in large numbers on the rhizomes. The gemma may germinate into new plant when it is still attached to the parent plant or when they fall on the suitable substratum after detachment.