Note on Economic importance of Gymnosperms
Economic importance of Gymnosperms:-
1. Food:-
> In some parts of India, Malaya, Philippines and Indonesia, young succulent leaves of various species of Cycas are cooked and eaten as vegetable.
> The famous “Sago” starch is obtained from the stem / seeds of Cycas and used as food. This stem starch obtained from Macrozamia spiratis is an important source of food for poultry, dairy animals and pigs.
> The seeds of Cycas are used as paste and eaten as cakes in Nicobar Island.
2. Green Manure:- Leaves of Cycas are rich in nitrogen and used as green manure for rice, sweet potato and sugarcane.
3. Medicine:- Leaf extract of Ginkgo biloba is useful in the treatment of cerebral insufficiency and vertigo.
4. Ornamental:-
> Ginkgo biloba and Cycas species are grown as an avenue tree and in gardens also for beautification.
> These trees are preferred especially due to their slow growth, evergreen nature and beautiful symmetry.
5. Timber:-
> Conifers and Taxales are most important genera of gymnosperms significantly important to produce high quality, straight grained, light colored, high weight and strong wood in comparison to their weight.
> They are suitable for making cabinets and furniture due to their strength and durability.
> The wood of Abies is light and termite free. It also has pleasant scent smell and used for packing cases, match wood, wood wool, aircraft work, plywood, light camp furniture and also used as household materials.
> Juniperus wood is fragrant, reddish brown and rarely damaged by insects.
> Cedrus wood is also durable, oily, fragrant, insect repellant and rot resistant.
> The wood of Taxus is strong, oily, elastic, close- grained, fragrant and very durable with smooth glossy surface.
> Beside this, wood of Araucaria canninghana used for plywood manufacture.
6. Resin:-
> Conifers exudated resins, this help the wood resistant to decay.
> Conifers are the major resin yielders of the world. These resins evaporate their oil and became harder which makes them invaluable in paints, varnishes, paper sizing, medicines and liquors industries.
7. Canada Balsam:- A resin obtained from Abies balsamea which has a very high refractory index approximately that of glass. Due to this property it is extremely suitable as amounting medium for microscopic objects and as cements for uses in optical work.
8. Essential Oils:-
> All conifers young branches and adherent leaves provide essential oils.
> Himalayan Cedar oil (Cedrus deodara) and Red Cedar Wood (Juniperus virginiana) are used cleaning tissues in histological work and also use with the oil immersion lens of the microscope.
> The oil obtained from Cedrus atlantica possess medicinal properties and used against bronchitis, tuberculosis, skin diseases and gonorrhea.
> The essential oils are used extensively in preparation of deodorants, room sprays, disinfectants, perfumery and medicine etc.
9. Fatty Oils:-
> Many conifer seeds are rich in fatty oils.
> The oil from the seeds of Pinus cembra and Torreya nucifera is edible and also used for paints.
> The Tail Oil obtained as a by product from sulphate process of cooking conifer wood for making Kraft paper is used in paints, soaps, linoleum, emulsifiers etc.
10. Pharmaceuticals:-
> The leaves of Taxus baccata are used in asthma, bronchitis, hiccough, epilepsy and for indigestion.
> Taxol (from Taxus brevifolia) is found effective against ovarian cancer, breast cancer, and melanoma and colon cancer.
> Ephedra is the source of a valuable drug Ephedrine obtained from E. equisetina, E. gerardiana, E. major, E. sinica, E. intermedia and E. nebrodensis. It is used against cold, respiratory disorder and hay fever.
> An aromatic beverage, known as Mormon tea is also brewed from the species of Ephedra in south western United State.
11. Amber:-
> It is a fossil, water insoluble tree resin which was secreted by the now extinct pine, (P. succinifera).
> It is yellow, brown to black, hard and brittle with an aromatic odor.