Latouchella

About Natural History

Archive for the month “February, 2014”

Why ferns are awesome

There are several reasons why one might like ferns. They are moslty known for beeing very green, bearing nice leaves, and thus serve decorative purposes. Some other times they are use as a basis for medicine. Unfortunately, they are not plants that are as much admired by the world as they would deserve.

For the biologists’ eye, the first fascinating thing about ferns is that their stems grow below the surface, and their roots are not parallel to this structure like they are for trees (in general) but perpendicular to the totality of the stem as shown in figure 1 below.

Fern

Figure 1: Schematic anatomy of ferns.

Another notable difference is the structure of the cells that are involved in the sexual reproduction: they are not part of the main plant (like the case of flower-bearing plants, Angiosperms), but they form another, separate, plant -the gametophyte- that consists of cells with one representative of each pair of chromosomes (haploid state) (figure 2).

fernlifecycle

Figure 2: Life cycle of ferns.

These are things that we learn during the first year of biological studies. For me though, the most amazing thing that characterizes ferns in general, is the fact that unlike pines and flower-bearing plants (Conifers and Angiosperms), their vascular system is in the center of the leaves, the rhizome and the roots. This characteristic feature isn’t found in many other type of plants today (considering that bryophytes do not have a completed vascular system), but could be found in numerous other plants that have disapeared mainly after the end of the Permian era. Also, the structure of the vascular system varies between different taxa. This is something that attests to the exploration of these plants in order to find different solutions for the transportation of water and nutrients from one part of the plant to another. And we are able to see the traces of this exploration that took place very early in the evolution of ferns, not by time travelling but by observing today’s plants. A wonderful group of organisms!

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