Tempskya, growing millions of years ago

Tempskya is an extinct genus of tree-shaped ferns, the fossils of which have so far only been found in Cretaceous layers. The Cretaceous is a geologic period and system that spans 79 million years from the end of the Jurassic period 145 million years ago to the beginning of the Paleogene period 66 million years ago.

The stem-shaped structure of Tempskya is called "false stem" because it is formed by an entanglement of large numbers of stems and roots. The upward growing stems, which have a diameter of 2.5-10 mm, gave large numbers of roots (diameter about 1 mm) that grew downwards. They formed a felt-like mass around the stems. Because the stems branched regularly, a very solid whole was created. On a cross section of a trunk (see the images) the relatively large stems and the small roots can be seen.

 

New Zealand flax

Phormium tenax or New Zaeland flax are evergreen perennials, making a large clump of leathery, strap-shaped leaves coming to a decided point, with tall panicles of small, tubular flowers in summer.

New Zealand flax is an excellent fiber plant, hence the association with real flax (Linum usitatissimum) that is grown in Europe. The fibers of the leaves, up to 2 m long, were used by the Maori to make clothes, bags and shoes, and later the Europeans made rope and sails. All parts of the plant were used: for medicine made from roots, face powder from flower pollen and old blooming stems roped together as rafts.

Just a beautiful preparation

Here we see the images of a beautiful preparation made by Mike Smith. The cross section trough the ovary of Buddleia globosa shows many details. Note that the ovary (and later the seed capsule) is covered in tangled hairs (stellate-tomentose) and how the base of the style is also hairy. The second fluorescence image shows this in detail.

From North America to anywhere else

Ceratophyllum demersum is a native of North America. It now has a worldwide distribution, at least in part due to the aquarium and pond trade. It is a submerged aquatic plant which is capable of forming dense monospecific beds, excluding other plant species, causing problems to recreational activities on waterways and in some cases causing blockages at hydroelectric power stations. C. demersum can spread rapidly, and grows in a large range of aquatic habitats.

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.

No plants and trees without symbiosis

Mycorrhizas are symbiotic relationships between fungi and plant roots (the term means literally 'fungus root') Perhaps more than 80% of the species of higher plants have these relationships, and so do many pteridophytes (ferns and their allies) and some mosses (especially liverworts). They are as common on crop plants (cereals,

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