Other Plants

Other plants include algae, lichen, horsetails and ferns.

Algae – Although many algae are green and some superficially look like plants they are not related to plants. They belong to a group called Protista along with many organisms that bear characteristics similar to both the plant and animal kingdoms including amoeba, diatoms, slime moulds and protozoa.

Algae come in many forms and sizes, from single celled organisms invisible to the naked eye, through to giant seaweeds. They are mainly red, brown or green and can be found living almost everywhere. Some have been found living in caves with no light, others in boiling-hot springs and some grow on animals. You will most commonly come across algae in slow moving freshwater or in the sea.

The thick green mats, which sometimes cover the surface of ponds, usually consist of an alga called Spirogyra. The mat consists of millions of tiny filaments made from chains of individual cells joined head to tail.

We are all familiar with seaweeds. They come in a wide range of forms, the largest in our region being Laminaria hyperborean. The most commonly found seaweed on our coast will be one of a group known as the wracks.

Algae can also be found living in partnership with other organisms. Some corals have algae living within their cells providing oxygen and converting nutrients. Lichens are a partnership between an alga and a fungus.

For further information go to: www.seaweed.ie/default.html or www.algaebase.org

Ferns – The fern familiar to most is bracken. This is a very successful plant that uses underground shoots to spread. It can cover huge areas of upland and land managers there expend a lot of effort trying to control it. Wherever you are in the region you will be less than 20km from a bracken plant. Unlike bracken most of the other ferns grow from a central point forming a circular clump a bit like a shuttlecock. There are others that do not follow this form, including the adder’s tongue and moonwort.

For further information go to: www.nhm.ac.uk/hosted_sites/bps/index.htm

Horsetails – These ancient plants are all closely related and therefore look very similar. They have a jointed main stem and many have rings of ‘branches’ along its length. The tip of the plant has a small dark cone that contains the spores from which the next generation will develop. Most gardeners will recognise this plant as a determined weed.

For further information go to: www.nhm.ac.uk/hosted_sites/bps/index.htm

Grasses – Most grasses follow a simple form that can be seen in the grass that grows in domestic lawns. Many have underground stems that allow them to spread rapidly and colonise new areas. The leaves, called blades, are long and thin and many have a distinct central vein. Grasses grow on the tops of the fells down to the foreshore and everywhere in between. Many have become specialised and it is possible to tell what type of soil and in some cases underlying rocks occur in an area by looking to see which grasses are growing there. The flat grassland you see in the countryside is a result of keeping grazing animals on the land. Without grazing the grasses would be allowed to grow forming clumps and tussocks. This can be detrimental to smaller plants, which require grazing to allow them to compete with the grasses.

For further information go to: http://www.rbgkew.org.uk/data/grasses-db.html

Sedges – Sedges are often misidentified as grasses. They can often be recognised by their stiff three-sided stems. They are usually found in wet areas and form clumps if left ungrazed.

Rushes – Rushes are similar to both sedges and grasses in that some have narrow long blade-shaped leaves and form clumps. Some rushes have very small leaves and what appears to be leaves are in fact the stems of the plant. These will often be filled with a white foam-like pith.

Reedmaces – These are tall grass-like plants that grow in or alongside water. They have large sausage shaped brown flowers that break up into fluffy windborne seeds.

Protista

This is a kingdom comprised of simple, unicellular ‘animals’ that do not fall easily into the plant and animal kingdoms.

Protists exhibit an enormous range of body form, even though they are largely microscopic. They may occur singly or in colonies. They may swim freely, travel along a surface, or be fixed to a surface. They may be housed in a shell, clothed in scales or other adhering matter, or be naked. They may or may not be coloured. They may be parasites; or they may live, apparently harmlessly, attached to or within plants or animals.

Protists were traditionally (for the last 150 years) subdivided into several groups based on similarities to the higher kingdoms: the animal-like protozoa and the plant-like algae and the fungi-like slime moulds. These traditional groups often overlap. The traditional classification is fundamentally flawed and new systems are proposed and likely to be adopted. In some newer schemes, most algae are classified in the kingdoms Plantae and Chromista, and in such cases the remaining forms may be classified as a kingdom Protozoa. The name is misleading, since they are not truly ‘animals‘.

Protozoa (in Greek proto = first and zoa = animal) are single-celled eukaryotes (organisms whose cells have nuclei) that show some characteristics usually associated with animals, most notably mobility and heterotrophy. Protozoa have traditionally been divided on the basis of locomotion, as below, although this is no longer believed to represent genuine relationships:

-	Flagellates
-	Amoeboids
-	Sporozoans: Apicomplexa, Myxozoa, Microsporidia
-	Ciliates

Most protozoans are too small to be seen with the naked eye – most are around 0.01-0.05 mm, although forms up to 0.5 mm are still fairly common – but can easily be found under a microscope. Protozoa are ubiquitous throughout aqueous environments and the soil, and play an important role in their ecology. Protozoa occupy a range of trophic levels. As predators upon unicellular or filamentous algae, bacteria, and microfungi, protozoa play a role both as herbivores and as consumers in the decomposer link of the food chain. Protozoa also play a vital role in controlling bacteria population and biomass. As components of the micro- and meiofauna, protozoa are an important food source for microinvertebrates. Thus, the ecological role of protozoa in the transfer of bacterial and algal production to successive trophic levels is important. Protozoa are also important as parasites and symbionts of multicellular animals.