Tung is a small to medium-sized deciduous tree growing to 15 m tall, with a spreading crown.
The fruit is apple sized, hard, green initially, turning green to purple and dull brown when ripe,
containing usually 4 or 5 large oily seeds 2 to 3 cm long with a hard outer shell.
The nuts yield about twenty percent oil.
Tung trees are very exacting in climatic and soil requirements.
Major growing areas include China, Argentina, Paraguay and Thailand.
Tung trees are usually in commercial production by the fourth or fifth year, attaining maximum production in 10-12 years. Average tree life is 30 years. Under favourable conditions an acre of Tung trees will produce about two tons of nuts and one hundred gallons of raw Tung Oil annually.
Linseed plant - Linum usitatissimum
Linum usitatissimum is an annual plant grown for its seeds (Linseed) or for its fibre (Flax).
Lindeed flowers are usually blue, but can be pale blue or white.
They have 5 petals 15-25 mm diameter on stalks 60 - 80 cm tall.
The seed capsule is round, 5-9 mm diameter and contains several seeds.
The seed which is harvested in September is dark brown and shiny.
Dried seed contains from 33 to 45 percent oil.
A hectare usually produces between 1.5 and 2 tonnes of Linseed.
The UK is self sufficient in Linseed.
Raw Linseed oil is the oil extracted from the seeds by mechanical pressing.
Boiled Linseed oil is not boiled, it has metal driers added to speed drying time.
Refined Linseed oil has the proteins removed so it does not go black after application.
Stand oil and Blown oil are heat treated to polymerise the oil.
Linseed oil used in Le Tonkinois varnish manufacture is refined and heat treated.
The description on this page is based on information copied from various sources.