What is an indusium in a fern?
A flap of tissue that protects the sori in some ferns. This can take a variety of forms. When spores are mature and ready for release, the indusia usually shrivel or bend backwards to expose the sporangia. Occasionally, if the indusia completely cover the sporangia. they may tear irregularly.
What are the characteristics of ferns?
Similar to flowering plants, ferns have roots, stems and leaves. However, unlike flowering plants, ferns do not have flowers or seeds; instead, they usually reproduce sexually by tiny spores or sometimes can reproduce vegetatively, as exemplified by the walking fern.
What is the specialized structure of fern?
The structure of a fern. Ferns have 3 major parts – the rhizome, the fronds and the reproductive structures called sporangia. The characteristics of each of these 3 parts of the fern plant are used for classification and identification.
Where would you expect to find an indusium on a fern?
The indusium is attached at the lower edge and partially under the sorus. The hoodlike indusia of fragile fern are easy to see early in the season.
Do all ferns have indusium?
Sori appear as brown spots and may or may not be present on all leaves. Some species have sori on all the leaves, while others have specialized leaves that bear the sori.
What is indusium give its function?
1. a membranous outgrowth on the undersurface of fern leaves that covers and protects the developing sporangia.
What are the adaptations of a fern?
The most notable adaptation made by ferns is the presence of a rhizome. The rhizome, or stem, of the Licorice Fern develops horizontally beneath the soil, containing a growing tip that gives way to new frond development. The consistency of rhizomes can vary from wood-like hardness to plush-like softness in texture.
What are characteristics of pteridophyta?
The general characteristics of Pteridophytes are:
- They are seedless.
- They are multicellular.
- They reproduce through spores.
- They are independent and free-living organisms.
- They have a well-differentiated plant body into root, stem and leaves.
What are the horizontal stems of ferns called?
Ferns have horizontal stems called rhizomes. Their roots grow out of the rhizome.
What is false indusium in botany?
function in ferns In fern: The indusium. One is the so-called false indusium, a rolled-over leaf margin under which sporangia form and mature. The true indusium is a separate and unique formation, the structural origins of which are not clear, that constitutes a more or less papery covering over the sorus.
What is the difference between sterile and fertile ferns?
Sorus with a peltate shaped Indusium cover the entire surface in rows on the fertile fronds and are located on the top third of the frond. Fertile fronds are taller than the sterile fronds and die back while sterile fronds remain. Christmas ferns have a clumping habit that slowly form multiple crowns.
How many species of leptosporangiate fern are there?
These two labs cover some of the major families of leptosporangiate ferns (see Lab #3 for a chart that distinguishes between eusporangiate and leptosporangiate ferns), sometimes called the “higher ferns” or “true ferns.” This is a group that contains 30-50 families and ~10,000 extant species.
Are horsetails and scouring-rushes ferns?
Until recently, horsetails and scouring-rushes were placed in their own division Equisetophyta (Sphenophyta), but recently they’ve been shown to be quite closely related to ferns, and placed with ferns in their division Pterophyta. So let’s call them tube “tube ferns”!
Are Ohio ferns homosporous or spore forming?
They are mostly homosporous. In “leptosporangiate” ferns (which include most Ohio ferns) the spores are produced in minute globose sporangia, encircled by a belt of tissue –the annulus –that splits the sporagium when it is ripe.