Hedyotis diffusa Seeds | Snake-needle Grass
LATIN NAME: Hedyotis diffusa
COMMON NAME: Snake-needle Grass
Plant Profile
Snake-needle grass is a low, spreading perennial, 15-40 cm tall, with narrow opposite leaves and small white flowers borne singly in the leaf axils. The plant forms a loose mat of fine stems, and the whole plant is used in Chinese medicine.
It is a plant of disturbed ground, field edges and roadsides, and it appears in gardens as a weed as often as a crop. In cultivation it is grown in rows and harvested whole at flowering, then dried.
Hedyotis diffusa, now usually placed in Oldenlandia, comes from China, Japan and south-east Asia. It is one of the herbs in the classic Chinese formula known in the west as PC-SPES, and it has attracted research interest for that reason.
Science & Biotechnology
The plant contains iridoids, flavonoids and triterpenes, and extracts have shown cytotoxic activity against several cancer cell lines in vitro. That work is laboratory-based, and there is no clinical evidence that the herb treats cancer in people; the formula it belongs to was withdrawn from sale in the United States after contamination was found.
Oldenlandia is a large genus in the coffee family, and the species are difficult to tell apart without flowers. That matters because the medicinal trade depends on correct identification, and related species have been substituted.
The plant is also a host for root-knot nematodes, which is worth knowing before planting it in a vegetable rotation. In its native range it is a common weed of cultivated ground for that reason.
Uses & Benefits
The whole plant is used in Chinese medicine, usually in combination with other herbs, for conditions described traditionally as heat and toxin. It is also used in some Japanese and Korean formulas.
In the garden the plant is grown for seed production and as a ground cover in a herb plot. Commercially the dried herb is traded in Chinese medicine markets. It is not a culinary plant, and it should not be used for self-treatment. In warm climates the crop is cut twice a season, and the second cut is usually lower in the active compounds than the first.
Growing from Seed
Sow on the surface at 20-25°C, since the seed is fine and needs light. Germination takes two to three weeks. The seedlings are small and slow at first, so start them in a tray and prick out carefully.
Plant out at 20 cm apart in full sun or light shade, in moist, well-drained soil. Water regularly; the plant dislikes drying out. Harvest the whole plant at flowering, cutting at the base, and dry it in shade. Leave a few plants to seed for the next crop, since the plant self-sows readily. Broadcasting on a fine, moist seedbed mimics the plant’s natural habit, and the seedlings fill the gaps without any transplanting.
Our Take
A medicinal herb with more laboratory attention than clinical evidence, and one to grow only with a clear purpose in mind.
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