This cup lichen is common in forests, sand dunes and heathland. It grows between moss and grass and is about half a centimeter tall. It has a red-colored spore forming fruiting or apothecia.
Lichens are tough organisms which can survive on the most unlikely places, where plants cannot grow. For example, in the desert, in the Antarctic, in high mountains.
Lichens are a collaboration between fungi and algae. The fungus, which contains no chlorophyll, is dependent on the photosynthesis in the algae, the algae can exist also without the fungus. Through this partnership, the combination of both organisms survives. Most lichens live on water which is present in the air and the substances produced by the photosynthesis in the algae. They do have roots, but these serve for attachment and not for the absorption of substances.
Because lichens are dependent on the air, they are very sensitive to air pollution.
Usnic acid (C18H16O7) is found in Cladonia coccifera and especially in beard moss (Usnea) and has an anti-bacterial effect. It is quite easy to extract from the lichen with hot acetone. Usnic acid is widely used as an ingredient in creams, powders, toothpastes, mouthwash, deodorants, hair shampoos and sunscreen products.
Cleverly adapted to the amount of light
In addition to water, carbon dioxide, mineral salts, and heat, light is one of the factors which are of vital importance for the green plant. It provides energy for the photosynthesis and brings about the growth and development of plant forms. In addition to the light on itself, also the light intensity plays an important role. The leaves of deciduous trees are the place where the energy required for the plant is formed by photosynthesis and assimilation. This is done in the chlorophyll-containing cells of the palisade layer. There below is loose fill and aerenchyma tissue. Outwardly a leaf is sealed off by a layer of epidermal cells, the outer walls thereof are thickened.
In fact, the light influences the construction of the plant and its leaves. We find sun leaves on the outer edge of the crown and on the south side of it, shade leaves inside the crown and on the north side (this applies to the northern hemisphere) They show characteristics of sun and shade plants. In order to get a maximum amount of light, they put their leaf surface perpendicular to the incident light.
Sun leaves are thicker because their assimilation tissue, the palisade parenchyma, which has longer cylindrical cells, often lying close together in double rows. They contain numerous chloroplasts that lie along the long sides.
In the palisade parenchyma of the shade leaves however, there are shorter cells loosely standing next to each other in a single row. Their shape approximates that of the cells of the spongy parenchyma of the ventilation tissue. They also have less chloroplasts. In terms of volume, the intercellular spaces of the shade leaves are larger than that of the sun leaves, this in order to provide the cells with sufficient carbon dioxide at the lower possible exposure to light. Shadow leaves are larger and light green, sun leaves are small and dark green because of the numerous chloroplasts.
Medicine in roots and tubers
>Around 1600, Dahlia seeds from Mexico were transported for the first time to try them in Europe. In the beginning, there has been little note. Around 1800 there was more life in the brewery and the plant was pulled into bloom in the Botanical Gardens of Madrid. Later, the plant was seeded and grown in the Botanical Gardens of Berlin. The plant got its name in the Botanical Gardens of Madrid and was named after Andreas Dahl. This was a disciple of the then very famous Linnaeus. Around 1800, Dahl was studying botany in Madrid. From a minor position the Dahlia has developed herself, especially with the help of man, into a plant with over 20,000 species recorded.
Inulin is a starchy substance found in a wide variety of fruits, vegetables, and herbs, including wheat, onions, bananas, leeks, artichokes, and asparagus. The inulin that is used for medicine is most commonly obtained by soaking chicory roots in hot water. Inulin is used as a remedy against high blood fats, including cholesterol and triglycerides. It is also used for weight loss, constipation, and as a food additive to improve taste.
How does it work?
Inulin is not digested or absorbed in the stomach. It goes to the bowels where bacteria are able to use it to grow. It supports the growth of a special kind of bacteria that are associated with improving bowel function and general health. Inulin decreases the body's ability to make certain kinds of fats.
How to be heat and drought resistant?
The Oleander has big, red, white or yellow, highly fragrant flowers. The 7 - 8 m high shrubs are spread from the Mediterranean to East Asia, growing in sunny locations and near watercourses. In North West Europe it is often drawn as a container plant.
Its leathery, lance-shaped leaves show the characteristics of xeromorphic - that means drought resistant - sun plants. Oleander is adapted to the very hot and dry borders of watercourses in summer. A multilayer epidermis with a thick cuticle covers the leaf upper and bottom side. Underneath the top side lies a double row of palisade parenchyma. At the bottom side of the leaf, is a multi-row layer of palisade like cells with parietal chloroplasts. Between the two lies the loose spongy parenchyma with numerous, nearly parallel aligned vascular bundles. The latter stiffen the leaf.
Deep cavities, each containing multiple stomata and numerous hairs, break through the palisade layer at the bottom side of the leaf, reaching the spongy parenchyma. These provide a water vapor-filled, sheltered space, whereby the evaporation out of the leaf is being reduced. The cavities are very close together, therefore the leaf has many slit-like openings. These enable the leaf to assimilate intensively in humid conditions. In dry conditions however, they prevent evaporation by closing themselves. Oleander has sun leaves which are protected against evaporation.
Potatoes are everywhere
>Potatoes contain starch in the form of typical large oval spherical granules; their size ranges between 5 and 100 microns. Under the microscope, the granules can be seen clearly in polarized light.
Potato starch – also known as potato flour – is extracted from potatoes. The cells of the root tubers of the potato plant contain starch granules (leucoplasts). To extract the starch, the potatoes are crushed and the starch grains are released from the cells. The starch is then washed out and dried to powder. Potato starch has been produced in the same basic way for centuries – actually even the ancient Incas knew how to make potato starch.
Potatoes’ starch granules are roughly twice as big as other starch granules (tapioca or grain starches) resulting in much higher water absorption capacity and better texture. Potato starch is a very refined starch, containing minimal protein or fat. This gives the flour a clear white color, and the cooked starch typical characteristics of neutral taste, good clarity and transparency, high binding strength, long texture and a minimal tendency to foaming or yellowing of the solution.
As an additive for food processing, potato starch as well as other food starches are typically used as thickeners and stabilizers in foods such as puddings, custards, soups, sauces, gravies, pie fillings, and salad dressings, and to make noodles and pastas. Potato starch may be used in all traditional recipes replacing any other starch and in most cases giving better functionality.
Potato starch is used in many other applications such as: water binder, thickener, anticaking ingredient, bulking ingredient and gluing agent. The most popular application areas are in: the meat industry, bakeries, confectionery and dry blends.
Source: Finnamyl Ltd.
Breathing through your roots?
Mangrove is a type of forest in the tropics and subtropics, located along a low coast or a river, which is submerged at high tide, is sheltered and muddy, has a salty soil and is characterized by a vegetation consisting of trees and shrubs with breathing roots or aerial roots.
Mangrove has adapted to special nutritional circumstances. Between reef and beach where the surf is less ferocious, coral rubble and sludge will settle down. Because of the lower surf there is less oxygen. In such an environment mangrove trees often grow. They have rhododendron lookalike leaves and aerial root systems of all kinds to breathe air, since they cannot do so in the mud.
There are large intercellular spaces in the outer layers of the stilt or breathing roots of mangroves and other aquatic plants. They serve to provide the plants with oxygen.
When leaves are falling
Premature defoliation at the base of the leafstalk or petiole. Damage from road salt (ions)
The images show the prepairation of the cleavage of tissue at the base of the petiole. During the perspiration, ions, which are introduced via the roots, constantly remain behind in the leave tissue, which accumulate over time to such an extent, that they slow down the photosynthesis. In addition, the water supply in freezing weather becomes so difficult, that the perspiration has to be greatly reduced. Therefore, our deciduous trees shed their leaves in autumn or sooner, also depending on the amount of accumulated ions. This is an active, hormonally controlled process, which takes place in a separating layer consisting of multiple layers of parenchyma cells, at the base of the petiole. There, several enzymes dissolve either the middle lamellae alone, or together with the primary walls or the entire cells. Then the vascular bundles tear off, and the leaf can drop. As the images show, the point of attachment of the petiole is protected from dehydration and infection, by a layer of cork, which has already been laid out before the leaf falls.
Tar spot (Rhytisma acerinum)
>The microscopic image shows an infected leaf with sclerotia. A consequence of monoculture.
Just like buildup of mold on pine needles and on the leaves of the willow, an ascomycete (Rhytisma) is the cause of tar spot. From late summer to autumn, round black mold deposits are growing on the leaves of several species of maple, which overwinter on the ground after the falling of the leaves. In spring distribution follows via the light and far away floating mold spores. If maples are standing close together in species-poor mixed forests, the fungus can spread excessively. The photosynthesis of infected leaves is severely hampered by the non-translucent mold deposits. The consequences are that the formation of wood will slow down and that the tree will weaken. The parasitic ascomycete gets its energy from the vascular bundles of the leaf, via its string-like hyphae, which can be recognized in the cross section of an affected leaf.
Formation of black spots on maple leaves in autumn.
Mold class: Ascomycetes
Sclerotia: Hardened form of tissue
A bio-indicator for air pollution
>Growth of lichens on trees: Bio-indicator for clean and contaminated air. Lichens are dual beings, developed from a symbiosis of algae and tiny fungi. Fungi and algae alone are dependent on moisture. As a community, however, they prefer dry places. Because of the slow growth and the great loyalty to their habitat, no other group of plants is so suitable to display properties of permanent locations. Lichens are highly sensitive biological indicators of changes in conditions of a habitat. By aggressive air constituents such as nitrogen oxides and heavy metals, lichens stock is destroyed gradually.
The community life of fungi and algae in need of moisture, protects itself against evaporation and radiation of sunlight by special provisions of the supporting tissue. By aggressive air constituents such as nitrogen oxides and heavy metals, this protective features of lichens are destroyed. Photosynthesis in the symbiotic algae is significantly impeded. The result is a slow dehydration and destruction of the lichen. Although many species of lichens can live under extreme conditions (well below -20 °C and at temperatures above +70 °C), some species react particularly sensitively to pollutants in the air. Therefore they are considered as so-called bio-indicators of contaminated air. As long as these kinds of lichens occur frequently on trees or woodland, this indicates no or little contaminated air. Some lichens would be able to reach an age of more than 100 years. Lichens are characterized by a very wide variety of shapes and colors.
A cactus takes breath at night
>A cactus takes breath at night Most plants have their pores (stomata’s) open during the day to take in carbon dioxide, and usesunlight as a catalyst for the photosynthesis. But in thedesert, plants with pores open during thehot days, lose much water through evapotranspiration. So, succulents use a modified version ofphotosynthesis called CAM (Crassulacean Acid Metabolism). CAM plants open their stomata’sonly at night when it is cooler so there is less evapotranspiration. Because there is no sunlight toact as a catalyst, carbon dioxide is stored as an organicacid, principally Malic Acid (C4H6O5).
Carbon dioxide is gradually released from the acid during the next day. CAM plants use aboutone-tenth the water to produce each unit of carbohydrate compared to standard photosynthesis.The price: a much slower growth rate. Many plants contain malic acid, but usually in lesserquantities than found in cacti. Besides malic acid, succulents produce oxalic acid(C2H2O4),which is toxic, as another product of photosynthesis.“Its chief function seems to besequestering metals, principally calcium. Calcium oxalatesoften occur as crystalline mineralswithin the cactus pulp. Their function seems to be aiding structural integrity and enzymaticprocesses.
In fact two crystalline calcium oxalate mineralshave been identified in all cactitested: CaC2O4.2H2O (weddellite) and CaC2O4.H2O (whewellite).”Oxalates are also formedwith heavy metals such as copper, perhaps to reduce toxicity to the plant.
Pollen give honey its fingerprint
The annual rings of a tree trunk tell us a lot
Glittering crystals in the wood of larix decidua
A japanese woodblock print?
Who eats banana stems?
Living apart together
DoddDodder, a spiraling parasite
Fragilaria, a fragile kind of diatom
Desmids, beauties in microscopy This photomicrograph shows Micrasterias fimbriata, a type of green alga called a desmid. Micrasterias fimbriata belongs to one of the rare desmids of the Lowlands. This one was recently found in a fen in the north of Belgium. Micrasterias is named from the Greek mikros,"small" plus aster, "star".
Iris germanica, leaf of a monocotyledon plant, cross section
Too many mouths?
Workhorse Aspergillus Niger
Algae have sex too!
Algae have sex too! (at least some of them, though who knows if they enjoy it?) Amongst the Zygnemaceae, the process of conjugation consists of the joining together of the contents of two haploid cells from (usually) different filaments.
Conjugation in Spirogyra: the filaments show the typical results of scalariform ('ladderlike') conjugation. Two filaments lie parallel, and outgrowths from each filament grow towards each other, and then fuse to form a conjugation tube. The conjugation tubes allow the contents of one cell to transfer to the other. The dark oval shapes are diploid zygospores, formed after nuclear fusion between the two haploid cells. They form in only one of the two filaments. Sometimes more than two filaments take part in conjugation like a 'menage a trois'.
Spirogyra is a filamentous green alga in which the chloroplast has a characteristic spiral shape. In one of the photographs, you can see the chloroplast coiling against the outer edge of the cells. The numerous small round blobs along the edges of the chloroplast are the pyrenoids. The larger, faint blobs (they look like out-of-focus regions) that take up most of the volume of the cells in the filaments on the right are the nuclei, which are suspended in the interior of the cells.
Pyrenoids occur in many of the algae and are associated with the chloroplasts. Some of them are known to contain Rubisco, the enzyme that catalyzes the incorporation of inorganic CO2 into carbohydrate (Graham and Wilcox, 2000). In these algae, pyrenoids probably function to fix carbon. In other algae, pyrenoids are the sites of carbohydrate (typically starch) storage. Starch and iodine react to produce a deep blue- black color, so staining a thin algal prep with iodine will indicate the presence of pyrenoids.
Sources: Algalweb, MadSci Network
Small is beautiful
Diatoms, exhibition mount by Klaus Kemp (UK) The fine glassy details of diatoms are admired already for hundreds of years, ever since the invention of the microscope. During Victorian times, manipulation and studying of diatoms was considered an art and a pastime, and slides with different species of diatoms were used to thoroughly evaluate the latest microscope objectives for performance.
The diatoms are one of the largest and ecologically most significant groups of organisms on earth. They are also one of the easiest to recognize, because of their unique cell structure, silicified cell wall and life cycle. They occur almost everywhere that is adequately lit (because most species need light for photosynthesis) and wet - in oceans, lakes and rivers; marshes, fens and bogs; damp moss and rock faces; even on the feathers of some diving birds. Some have been captured by other organisms and live as endosymbionts, e.g. in dinoflagellates and foraminifera. Because of their abundance in marine plankton, especially in nutrient-rich areas of the world's oceans, diatoms probably account for as much as 20% of global photosynthetic fixation of carbon, which is more than the entire world's tropical rainforests
Algae in all colors of the rainbow