What is the Economic Importance of Gymnosperms?
Gymnosperms are other types of vascular and non-vascular plants of the Kingdom Plantae, which produce seeds directly (without) bearing any flower. Compared to angiosperms, there are far fewer types of gymnosperms. These non-flowering plants are found mainly in cold climates, boreal forests, and cool forests. They are evergreen plants, which can live in any habitat. In these plants, reproduction can be done either sexually or asexually.
Compared to angiosperms, plant species of gymnosperms are relatively few in number. This is because they produce naked seeds, which are damaged by birds, animals and other natural elements before they are released. In order for the seeds to disperse and continue the life cycle, they receive pollen from the air. Some of the examples of gymnosperms are cypress, larix, redwood, cycads, juniper, fir, etc.
Economic Importance of Gymnosperms
- Resin: Resins are plant exudates secreted in specialized ducts. These largely come from conifers as a result of tapping. They are insoluble in water and soluble in organic solvents and find extensive use in varnishes, paints, licquers, medicines and in paper manufacturing. Various kinds of resins and their sources are given below. For More Biology Doubts visit main page of Physics Wallah.
- Rosin: Rosin (colophony) is obtained as residue after the distillation of pine oleoresin or turpentine. Indian turpentine is chiefly tapped from Pinus roxburghii, P.wallichianu, P.insularis and P.merkusii. It is distilled to obtained rosin and turpentine oil. Rosin is used in paper sizing, varnish making enamels and in the preparation of plasters and ointments. Inferior grades of rosin are used in making yellow laundry soap, grease and oil, sealing wax, oilcloth, plastics, adhesive, insulator, insecticides, disinfectants, shoe polish, furniture and in several other commercial articles.
- Copal: Copal is tapped from Agathis austrilis as a green gum or candle gum.
- Canada balsam: Canada balsam is obtained from Abies balsamea. It has a high refractive index as that of glass and is used as a mounting medium for microscopic objects and as a cementing agent for lenses in optical work.
- Sandarc: Sandarc is obtained from various Australian species of Callitris and from African Tetraclinis articulata. Resin of Australian types exude naturally from various species of Callitris and is used as metal varnish giving good lusture when applied in thin coats. It is also used as paper and leather varnish. In present day pharmaceuticals it is used as pill varnish. Cotton wool dipped in its alcoholic solution is used as temporary filling for teeth. In Arabian countries it is used as a remedy for diarrhoea. Resin of African type is obtained by tapping Tetraclinis articulata. It is pale yellow or orange and contains about 1 % volatile oil.
- Venice turpentine: Venice turpentine is obtained from Larix decidua. It is used for making special type of varnish and veterinary medicines. Jura turpentine is obtained from Picea abies and is used in making specific paints and varnishes.
- Essential oils: Various kinds of essential oils are obtained from different species of coniferous plants. Abies sachaliensis gives an essential oil Japanese pine needle oil’ that is used for making scented soaps. Similar oil obtained from Cedrus atlantica and C. deodara is also used in perfumery and in medicines to cure bronchitis, tuberculosis, skin diseases and gononhoea. Picea glauca yields a similar essential oil is used as a constituent of room sprays.
- Fatty oils: Fatty oils are extracted from various species of gymnospérmous plants. Fleshy outer layer of the seed of Macrozamia yields oil that has properties similar to palm oil. Some species of Toireya (T. nucifera), Cephalotaxus (C. drupacea) and Pinus (P cembra yield fatty oil from their seeds that are used as food and for paints. Oil obtained from the seeds of Gnetum ula is used for illumination.
- Fibres: Stuffing fibres are obtained from ramantal hairs removed from the leaf bases of Macrozamia. Bark of Gnetum gnemon yields fibres of high tensile strength and are used for making ropes and fishing nets.
- Paper: Paper is made from wood pulp of some Indian species of coniferous plants (Picea smithiana, Pinus roxburghii, Abies pindrow, Cryptomeria japonica etc). Various species of Pinus us provide newsprint almost all over the world. High grades of paper are made from the wood pulp of Abies balsamea and species of Picea and Tsuga. Pulp obtained from stem fibres of Gnetum gnemon is also used for making paper.
- Food: The stem and the seeds of Cycas yield starch sago or arrow Kernels of Dioon edule are eaten after roasting and bread is made from the boiled seeds. The outer covering (sarcotesta) of the seeds of Pinus and Macrozamia is also eaten. Seeds of Pinus gerardiana (chilgoza) and other species of Pinus are edible. Seeds of Gnetum gnemon, G. latfolium and G. ula are also edible. Young leaves and strobili of G. gnemon are cooked as vegetable.
- Medicine: Resin obtained from Cycas rumphii is applied to ulcers. Cedrus deodara wood possesses diuretic and carminative properties and finds use in curing pulmonary disorders, piles and rheumatism. The oil obtained from Cupressus semipervirens possesses vermifuge properties. Seeds of Pinus gerardiana yield an oil that is applied as dressing to wounds and ulcers. The leaves of Taxus baccata are used in asthma, bronchitis cough, epilepsy and for indigestion and the seeds as sedative. Ephedra (E. intermedia, E. nebrodensis and E. gerardiana) contains good quantities of ‘ephedrine’ that is used against asthma, hay fever and bronchial troubles. The fruit juice of Ephedra is applied to cure respiratory troubles.
- Ornamentals: Several species of Cycas are extensively grown as garden plants and for decorative purposes. Ginkgo, the maidenhair tree’ is grown as an ornamental plant in the temples in China and Japan and is worshipped. Thuja plicata, Biota orientalis and species of Juniperus are cultivated as ornamental trees throughout India especially in the planes. Species of Pinus and Aurocaria are also raised as ornamental plants in North India. Some species of Gnetum and Ephedra are also grown as ornamentals.
- Poisonous Properties: Pollen grains of Cycas circinalis possess narcotic properties. Leaves of Macrozamia are poisonous and may cause rickets if eaten continuously by animals. Eating seeds of Ginkgo in larger quantities may prove fatal. Taxus baccata is used as a fish poison on account of presence of an alkaloid toxin. Gnetum monttimun is used as a fish poison.