Bu Gu Zhi
Psoralea corylifolia
Family: Fabaceae or Leguminosae
What it is like
Psoralea corylifolia is a ANNUAL growing to 0.6 m (2ft). It is in flower from July to August, and the seeds ripen from September to October. The species is hermaphrodite (has both male and female organs) and is pollinated by Insects. It can fix Nitrogen. Suitable for: light (sandy), medium (loamy) and heavy (clay) soils and prefers well-drained soil. Suitable pH: mildly acid, neutral and basic (mildly alkaline) soils. It cannot grow in the shade. It prefers moist soil.
Height (m): 0.6
Where it is found
Warm valleys in Guizhou, Sichuan and Yunnan Provinces, China.
Asia, from Iran to China, Africa and the Middle East.
Conservation Status:
Countries/locations it is found in
How it is used
Food
Rating: 1
Seed. No further details are given.
Seed: includes nuts, cereals, peas and beans.
Medicine
Rating: 4
Bu Gu Zhi is valued in Chinese herbal medicine as a tonic remedy and is used to improve general vitality. Modern research has shown that it is also of value in the treatment of skin disorders, including vitiligo. Some caution should be employed when applying the herb externally, however, since it can sensitise the skin and cause an allergic reaction to sunlight. The one-seeded fruits (or the seed plus the seedpod) are highly regarded as an aphrodisiac and tonic to the genital organs. The seed is anthelmintic, antibacterial, aphrodisiac, astringent, cardiac, cytotoxic, deobstruent, diaphoretic, diuretic, stimulant, stomachic and tonic. It is used in the treatment of febrile diseases, premature ejaculation, impotence, lower back pains, frequent urination, incontinence, bed wetting etc. It is also used externally to treat various skin ailments including leprosy, leucoderma and hair loss. The seed and fruit contain psoralen. This causes the skin to produce new pigment when exposed to sunlight and is used for treating vitiligo and psoriasis. The antibacterial action of the fruit inhibits the growth of Mycobacterium tuberculos. The fruit is gathered when ripe in the autumn and can be dried for later use. The root is used for treating dental caries. The plant yields a useful medicinal oleoresin, it treats kidney disorders, impotence, premature ejaculation, lumbago etc.
Anthelmintic: Expels parasites from the gut.
Antibacterial: Kills bacteria.
Aphrodisiac: Increases the sexual appetite.
Astringent: Produces contraction in living tissue, reducing the flow of secretions and discharges of blood, mucus, diarrhoea etc.
Cardiac: Used in the treatment of heart problems.
Cytotoxic: Destroys body cells. Used in the treatment of diseases such as cancer, where it is targeted against the cancer cells.
Deobstruent: Clears obstructions from the natural ducts of the body.
Diaphoretic: Induces perspiration.
Diuretic: Acts on the kidneys, promoting the flow of urine.
Infertility: Used in treating problems of human fertility.
Kidney: Used in the treatment of kidney diseases
Leprosy: Used to treat leprosy - a chronic bacterial infection of the skin and superficial nerves (in the skin) caused by Mycobacterium leprae.
Odontalgic: Treats toothache (temporary measure only) and other problems of the teeth and gums.
Skin: Plants used in miscellaneous treatments for the skin.
Stimulant: Excites or quickens activity of the physiological processes. Faster acting than a tonic but differing from a narcotic in that it does not give a false sense of well-being.
Stomachic: Aids and improves the action of the stomach.
Tonic: Improves general health. Slower acting than a stimulant, it brings steady improvement.
Other
Rating:
Nitrogen Fixer: Plants that fix nitrogen in the soil
How it is grown
We have very little information for this species and do not know if it will be hardy in Britain, though judging by its native range it should succeed outdoors at least in the milder parts of the country. The following notes are based on the general needs of the genus. Succeeds in an ordinary garden soil. Requires a well-drained soil in a sunny position. Plants are very intolerant of root disturbance, they are best planted out into their permanent positions whilst still small. This species has a symbiotic relationship with certain soil bacteria, these bacteria form nodules on the roots and fix atmospheric nitrogen. Some of this nitrogen is utilized by the growing plant but some can also be used by other plants growing nearby.
Propagating it: Pre-soak the seed for 24 hours in warm water and then sow in early to mid spring in a greenhouse. Either sow the seed in individual pots or pot up the young seedlings as soon as possible in order to avoid root disturbance. Grow them on in the pots until planting out in their final positions. It is usually impossible to transplant this species without fatal damage to the root. Division in spring. With great care since the plant resents root disturbance. It is virtually impossible to divide this species successfully.
Best place to grow: Cultivated Beds;
Habit: Annual
Hardiness:
Growth:
Soil: Light (sandy), medium, heavy (clay)
Shade: No shade
Moisture: Moist
Things to keep in mind
Although no specific mention of toxicity for this species has been found, at least some members of this genus contain furanocoumarins, these substances can cause photosensitivity in some people.