Write Short Note on Pinus
Short Note on Pinus
Pinus is found growing at an altitude of 5000-8000 feet.
- i) It is sporophyte, evergreen and quite tall tree.
- ii) It consists of extensive root system and strong branches.
iii) Upper branches becomes short and tree assume the shape of a cone.
It has two types of branches.
- i) Long shoots are produced on the main stem and continue growth by buds. They are covered by scale leaves.
- ii) Dwarf shoots originate in the axles of the scale leaves on long shoots. It bears 1-5 foliage leaves in addition to scale leaves. Each dwarf shoot with its cluster of needles is called a spur.
It has two types of leaves:
- i) Scale leaves are small and brown in colour. They cover the stem.
- ii) Foliage leaves are long, narrow and leathery. They are green.
It has two types of cones:
- i) Male cones
- ii) Female cones
Both male and female cones are produced on same tree but on different branches.
- i) Fertilization results in embryo formation.
- ii) Then ovule ripens to form seed.
iii) Female cones normally remain attached for three years on the plant.
- iv) When it matures the cones open and seeds are set free and dispersed.
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