Flatstem Milkvetch Seed(Sha Yuan Zi) are the dried and mature seeds of the leguminous plant Astragalus complanatus. They are primarily produced in regions such as Shaanxi and Hebei in China. 

Efficacy and Functions:

1. Tonifying Kidney and Boosting Yang: Flatstem Milkvetch Seed(Sha Yuan Zi) are sweet and warm, with astringent properties. They can tonify the kidney, boost yang, and help in consolidating essence and reducing urination. They are used to treat kidney deficiency with spermatorrhea, excessive leukorrhea, often combined with Dragon Bone, Oyster Shell, and Lotus Seeds. For kidney deficiency with lower back pain, they are often used with Eucommia Bark and Loranthus Stem.

2. Nourishing Liver and Brightening Eyesight: Flatstem Milkvetch Seed(Sha Yuan Zi)  enter the liver and kidney meridians, treating liver and kidney deficiency resulting in poor nourishment of the eyes, dimness of vision, dizziness, and vertigo. They are frequently combined with Chinese Wolfberry Fruit, Dodder Seed, and Chrysanthemum Flower to nourish the liver and kidneys, enrich essence and blood, and improve eyesight.

Contraindications:

Flatstem Milkvetch Seed(Sha Yuan Zi)  are warm tonics with astringent properties. They are not suitable for individuals with yin deficiency and excessive fire, or those experiencing difficulty urinating, to prevent exacerbating symptoms of excess heat.

Usage:

Flatstem Milkvetch Seed(Sha Yuan Zi)  are harvested when the fruits are ripe but have not yet split open, typically in late autumn or early winter. They are then dried, cleaned of impurities, and can be used raw or parched with saltwater.

Identification Techniques:

Flatstem Milkvetch Seed(Sha Yuan Zi)  are kidney-shaped but slightly flattened, measuring about 2-2.5mm in length, 1.5-2mm in width, and approximately 1mm in thickness. They have a smooth surface and are brownish-green or grayish-brown in color, with a circular hilum on one side. They are hard and not easily broken. The cotyledons are pale yellow, and the radicle is curved, about 1mm long. They have a mild odor and a slight beany taste when chewed.