Presentation on theme: " They are vascular seed bearing plants that can grow as shrubs, trees, or vines There are about 70 present day species of gnetophytes that are known."— Presentation transcript:
They are vascular seed bearing plants that can grow as shrubs, trees, or vines There are about 70 present day species of gnetophytes that are known placed in just three genera Gnetophytes fall under the phylum of Gymnosperms which are ancient surviving seed plants
Gymnosperms are the most ancient seed plants There are four groups of gymnosperms that are found today They include gnetophytes, cycads, ginkgoes, and conifers. All these plants reproduce with seeds that are exposed Gymnosperms are also known as cone bearers and it means “naked seed”
In Flowering plants the fruit or ovary wall covers the seeds, in gymnosperms the seeds are not covered in anything similar to that, that is why they call it naked seeds. These plants are fruitless and they do not produce flowers. THEY DOO HAVEE SEEDDS!!!
Ancestors of seed plants evolved to survive in many places other plants couldn’t The oldest plants included ferns and moss These ferns and mosses evolved into plants with seeds during the Carboniferous and Devonian periods which were 300-400 million years ago
There are three different types of gnetophytes on earth They all are very simmilar but have their differences and are used for very unique and benificial reasons The three types are 1.Ephedra 2. Gnetums 3. Welwitschia
Epherda are mostly found in dry climates mainly in the norther hemisphere, across south Europe, north Africa and central asia and mainly plant grows where it can get direct sunlight. example : deserts Epherda is very beneficial for medical purposes because it is used to treat asthma, hay fever, and the common cold.
The Chinese used this plant to cure symptoms of the common cold American settlers used it as tea called Mormon tea, and Squaw tea. Ephedra is still even used today in most over the counter medicine and in fat burning medicine These plants are mostly shrubby, with small scale leaves and jointed scales
Gnetums is a type of gnetophyte that are tropical evergreen trees, shrubs and lianas. Gnetums are very odd when being compared to Gnetophytes because they produce brad leaves with netted venation that are very simmilar to the ones found in flowering plants These Gnetums are found in South America, Africa and most parts of China
Gnetums are mainly edible therefore you can eat its seeds when there roasted and is used as a leaf vegetable, some are used as herbal medicine Gnetums are very special compared to other gymnosperms because they have high photosynthetic and transpiration capabilities with also a high capacity of xylem.
Welwitschia grows from a short, thick, woody trunk with only two leaves that continuously grow from their base, and long thick taproot. These plants grow very slow and are endangered, but despite being endangered, they live around for a long time.
These plants start of with two leaves and they grow and end up looking like if it had multiple leaves. They are mostly found in South Africa and has male and female cones. They can live for almost one thousand years
Most Gnetophytes are located in the desert or mountain in Asia, Africa, South America, and in the deserts of North America They need to be exposed to constent sunlight this is why you might find them in deserts
All of these plants reproduce with seeds that are exposed. The reproductive scales of these plants are cluisterd into cones Most gnetophytes produce separate female and male cones born on separate male or female plants