Pak Kei

This large genus of about 2,000 species of annuals, perennials, and shrubs is distributed throughout northern temperate zones. Several species are used for food and fodder crops and as a source of gel-forming substances. Some accumulate minerals, and are used as indicators in prospecting. Those toxic to livestock are known as "locoweeds". About 100 species are cultivated for their colorful spikes of flowers. Milk vetches are used both medicinally and a food and fodder crops in many parts of the world. Gum tragacanth is collected from at least 20 species, mainly A. gummifer, which has been the principal source since ancient Greek times. The roots of A. membranaceus provide traditional Chinese medicine with a tonic on par with ginseng. Astralagus membranaceus var. mongholicus is used interchangeably. It is similar in appearance but prefers damper habitats. Also important in Chinese medicine is A. complanatus (sha yuan), which has been used in China as liver and kidney tonic since the 12th century.

Sprawling perennial with pale yellow roots, and alternate, downy, light green leaves, 3-8cm (1½-3in) long, divided into 12-18 pairs of leaflets. Racemes of pale yellow, pea-like flowers, 2cm (¾in) long, appear in early summer, followed by papery pods, 2.5cm (1in) long, containing dark brown, kidney-shaed seeds.


Common Name:
Pak Kei
Other Names:
Huang qi, milk vetch
Botanical Name:
Astralagus membranaceus
Genus:
Astralagus
Family:
Papilionaceae
Native Location:
E Asia
Cultivation:
Well-drained soil in sun. Astralagus membranaceus prefers sandy, slightly alkaline soil.
Propagation:
By seed in spring or autumn
Harvest:
Gum is collected from second-year plants of A. gummifer by incising the stem base; it is dried for use as a powder. Roots of A. membranaceus are lifted in autumn and dried for decoctions, powders, and tinctures.
Height:
40-60cm (16-24in)
Width:
30-45cm (12-18in)
Hardiness:
Z5-8
Parts Used:
Roots (huang qi)
Properties:
A sweet, tonic, adaptogenic herb that stimulates the immune system, spleen, lungs, liver, circulatory and urinary systems, lowers blood pressure and blood sugar levels, and increases stamina.
Medicinal Uses:
An important ingredient in many traditional Chinese formulas; combined with Angelica polymorpha var. sinensis (See Chinese angelica) for sensitivity to cold, poor circulation, and low energy and with Atractylodes macrocephala (See Chinese thistle) and Ledebouriella seseloides for allergies and frequent colds. Also for diabetes, kidney problems, prolapsed organs, anemia, and slow-healing skin eruptions. Improves recovery and longevity in cancer patients undergoing chemotherapy or radiation treatment.
Culinary Uses:
Roots are eaten in rice porridge (congee) and tonic soups, often with chicken and combined with Codonopsis pilosula and Angelica polymorpha var. sinensis. Also as an ingredient of tonic teas and wine.
Bibliography:
Encyclopedia of Herbs by Deni Brown Copyright © 1995, 2001 Dorling Kindersley Limited Pp 136-137