What is the difference between cogongrass rhizome and heartleaf houttuynia, and how can you tell them apart quickly?

Cogongrass rhizome and heartleaf houttuynia are both medicinal plants, cultivated in most parts of our country.So what is the difference between cogongrass rhizome and heartleaf houttuynia?

1. What is the difference between cogongrass rhizome and heartleaf houttuynia?

1. Appearance

Cogongrass rhizome is long and cylindrical, 30-60cm long, 0.2-0.4cm in diameter. The surface is yellowish-white or pale yellow, slightly glossy, with longitudinal wrinkles, and the nodes are distinct and slightly raised, with internodes of varying length, usually 1.5-3cm long. It is light in weight, slightly brittle in texture, and the cortex of the cross-section is white, often with cracks arranged radially; the central stele is pale yellow and easily separated from the cortex. It has a faint odor and a slightly sweet taste.

The stem of heartleaf houttuynia is flat and round, shrunken and curved, 20-30cm long; the surface is yellowish-brown, with longitudinal ridges, and the nodes are distinct; remnants of fibrous roots remain at the lower nodes; it is brittle and breaks easily. The leaves are alternate. Mostly shrunken. When flattened out, they are heart-shaped, 3-5 long and 3-4.5cm wide; the upper surface is dark green or yellow-green, and the lower surface is greenish-brown or grayish-brown; the petiole is slender, and its base and the stipule form a sheath. The spike inflorescence is terminal. When crushed, it has a fishy odor and a slightly astringent taste.

2. Effects

Cogongrass rhizome is used for blood-heat hematemesis, epistaxis, hematuria, fever with restlessness and thirst, lung-heat cough, stomach-heat vomiting, damp-heat jaundice, edema with scanty urine, and painful strangury with heat.

Heartleaf houttuynia has the effects of clearing heat and detoxifying, promoting diuresis and reducing swelling. It is mainly used for pneumonia, lung abscess, heat dysentery, malaria, edema, gonorrhea, leukorrhea, carbuncle swelling, hemorrhoids, rectal prolapse, eczema, favus, and scabies.

3. Usage

Cogongrass rhizome is taken as a decoction, 9-30g. The fresh product is doubled. For stopping bleeding, it is mostly used after being charred; for clearing heat and promoting diuresis, it is suitable to use it raw.

Heartleaf houttuynia can be taken orally as a decoction, 3-5 qian (1-2 liang if fresh); or taken as expressed juice. For external use, it is decocted in water for fumigation and washing, or pounded and applied.