Common Name: Safflower

General Information

Carthamus tinctorius is an erect, thistle-like, often spined annual plant that can grow up to 180cm tall. The plant has a deep taproot and a strong stem with many branches, each terminating in a flower[, ].
Safflower has been grown for thousands of years for the dye that can be obtained from the flowers and for the oil-rich seeds[]. The dye is not much used nowadays, having been replaced by chemical dyes, but the plant is still widely cultivated commercially in warm temperate and tropical areas of the world for its oil-rich seed.

Known Hazards

None known

Botanical References

Range

The plant probably originated in west Asia (Turkey, Iran), but is widely cultivated around the world and is no longer known as a truly wild species.

Habitat

Poor dry soils in full sun.

Properties

Edibility Rating
Medicinal Rating
Other Uses Rating
Habit	Annual
Height	1.00 m
Pollinators	Bees, Insects
Self-fertile	Yes
Cultivation Status	Cultivated

Cultivation Details

Safflower probably grows best in the semi-arid subtropics, but cultivars have been developed that widen its range and it is now cultivated from the temperate zone to higher elevations in the tropics. It grows best in areas where annual daytime temperatures are within the range 20 - 32°c, but can tolerate 5 - 45°c[]. Seedlings can tolerate quite low temperatures, down to around -7 to -14°c according to cultivar at the rosette stage. However, they become more susceptible to frost damage as they grow larger, and temperatures of -2° can damage larger plants[, ]. The frost damages budding and flowering, thus reducing yields and quality[]. The plant prefers a mean annual rainfall in the range 600 - 1,000mm, but tolerates 300 - 1,400mm[]. Safflower is generally a long-day plant, with flowering normally being initiated by approximately 14 hours of daylight, but daylength-neutral varieties have been developed and daylength requirements can be modified by temperature, with high temperatures accelerating flowering[].
Requires a well-drained soil and a position in full sun[, , ]. Succeeds in ordinary garden soil[, ]. Safflower thrives in heavy clays with good water-holding capacity, but will also grow satisfactorily in deep sandy or clay loams with good drainage[]. Cultivars have been developed that can tolerate moderate levels of salt in the soil[]. The plant needs soil moisture from the time of planting until it is flowering[]. Prefers a pH in the range 6.5 - 7.5, tolerating 5 - 8[].
Safflower will not grow as a weed because other wild plants overshadow it before it becomes established[].
After germination, the seedling enters the rosette stage, characterized by slow growth, production of a rosette of leaves and development of a deeply penetrating taproot. When sown in spring, safflower generally has no rosette stage, while a long rosette stage occurs when it is autumn-sown[].
Safflower matures in from 110 - 150 days from planting to harvest as a spring crop, which is the way most of it is grown; and from 200 or more days as an autumn-sown crop[]. It should be harvested when the plant is thoroughly dried. Since the seeds do not shatter easily, it may be harvested by direct combining. The crop is allowed to dry in the fields before threshing[].
The average seed yield of safflower grown under rainfed, intensive cultivation has increased steadily to 1,500 kg/ha and nearly twice this under irrigation. Average yields in Ethiopia and India are about 500 kg/ha[]. Yields of straw are larger than those of small grain crops and may reach 5 t/ha[].
Safflower should not be planted on the same land for two consecutive years because it is susceptible to soil-borne fungal diseases[]..
Plants are self-fertile, though cross-pollination also takes place[].
Plants have a sturdy taproot that can penetrate 2.5 metres into the soil[].
There are many named varieties[, ]. A number of spineless cultivars have been developed, but at present these produce much lower yields of oil than the spiny varieties[].

Edible Uses

An edible oil is obtained from the seed. It contains a higher percentage of essential unsaturated fatty acids and a lower percentage of saturated fatty acids than other edible vegetable seed oils[]. The oil, light coloured and easily clarified, is used in salad dressings, cooking oils and margarines[, , , , , , , ]. A very stable oil, it is said to be healthier than many other edible oils and its addition to the diet helps to reduce blood-cholesterol levels[].

Seed - cooked. They can be roasted, or fried and eaten in chutneys[, , , ].

Tender young leaves and shoots - cooked or raw[, , ]. A sweet flavour, they can be used as a spinach[, ]. A famine food, it is only used when all else fails[].

An edible yellow and a red dye are obtained from the flowers[]. The yellow is used as a saffron substitute to flavour and colour food[, ].

The (fried?) seeds are used as a curdling agent for plant milks etc[].

Medicinal

Safflower is commonly grown as a food plant, but also has a wide range of medicinal uses. Modern research has shown that the flowers contain a number of medically active constituents and can, for example, reduce coronary heart disease and lower cholesterol levels[, ].

The plant is alterative, analgesic, antibacterial, antiphlogistic, febrifuge, haemopoietic, sedative, sudorific and vermifuge[]. It is used in the treatment of tumours and stomatitis[, , ]. When combined with Ligusticum wallichii it is said to have a definite therapeutic effect upon coronary diseases[].

The flowers are anticholesterolemic, diaphoretic, emmenagogue, laxative, purgative, sedative and stimulant[, , , , , ]. They are used to treat menstrual pains and other complications by promoting a smooth menstrual flow[] and were ranked third in a survey of 250 potential anti-fertility plants[]. In domestic practice, the flowers are used as a substitute or adulterant for saffron in treating infants complaints such as measles, fevers and eruptive skin complaints[, ].
Externally, the flowers are applied to bruising, sprains, skin inflammations, wounds etc[]. The flowers are harvested in the summer and can be used fresh or dried[]. They should not be stored for longer than 12 months[]. It is possible to carefully pick the florets and leave the ovaries behind so that seed can be produced, though this procedure is rather more time-consuming[].

The seed is diuretic, purgative and tonic[]. It is used in the treatment of rheumatism[] and tumours, especially inflammatory tumours of the liver[].

The oil is charred and used to heal sores and treat rheumatism[]. In Iran, the oil is used as a salve for treating sprains and rheumatism[].

Agroforestry Uses:

Intercropping safflower is possible and in Ethiopia safflower cultivation is closely associated with the distribution of teff (Eragrostis tef) and barley (Hordeum vulgare) with which it is mostly intercropped, Elsewhere, intercropping is not common because the yields are low as a result of competition[].

Other Uses

The seed yields up to 40% of a drying oil[], it is used for lighting, paint, varnishes, linoleum and wax cloths[, , ]. The oil can also be used as a diesel substitute[]. It does not yellow with age[]. When heated to 300°c for 2 hours and then poured into cold water, the oil solidifies to a gelatinous mass and is then used as a cement for glass, tiles, stones etc or as a substitute for 'plaster of Paris'. If the oil is heated to 307°c for 2½ hours, it suddenly becomes a stiff elastic solid by polymerization and can then be used in making waterproof cloth etc[].

A yellow dye is obtained by steeping the flowers in water, it is used as a saffron substitute[, , , , , ].
A red dye can be obtained by steeping the flowers in alcohol[, , ]. It is used for dyeing cloth and, mixed with talcum powder, is used as a rouge to colour the cheeks[].

The seed hulls have been used to make potting mixtures for nurseries, packing and insulation materials, and as filler for bricks[].

Propagation

Seed - sow spring in gentle heat in a greenhouse. Germination usually takes place within 2 - 4 weeks at 15°c[]. When they are large enough to handle, prick the seedlings out into individual pots and plant them out into their permanent positions in late spring or early summer.
The seed can also be sown in situ in mid spring[] but plants may not then mature their seed.