Apocynum venetum Seeds | Luobuma

Luobuma (Apocynum venetum) with narrow blue-green leaves and small pink bell flowers on erect stems — Luobuma (*Apocynum venetum*): Apocynaceae, a salt-tolerant fibre and tea plant of the desert margins of northern and western China.

LATIN NAME: Apocynum venetum

COMMON NAME: Luobuma, Chinese Dogbane

Plant Profile

Luobuma is a subshrub rather than a herb, and it builds a loose thicket of erect, reddish brown stems about a metre to a metre and a half tall from a creeping rootstock. The leaves sit opposite one another on the stem, narrow and lance-shaped, blue-green above and paler beneath, with a texture that feels almost leathery. Break a stem and it bleeds white latex, as any member of the dogbane family will, and that latex is the first thing to notice about the plant. The flowers are small, bell-shaped and pink to purple, held in loose clusters at the ends of the shoots through summer, and they are followed by long, slender pods that split to release seed attached to a tuft of white silk.

That silk is the source of the fibre the plant is grown for, and it is remarkably fine and strong, traditionally used for cordage, nets and cloth in the oases of Xinjiang. The species is native to the saline river flats and desert margins of northwestern China and Central Asia, where it survives on rainfall of a hundred millimetres and soils that would kill most plants. It spreads by rhizome into loose colonies and holds riverbanks and sand margins in place. The specific epithet is a historical accident and does not mean the plant comes from Venice; the name was attached by eighteenth-century botanists working from confused material.

Science & Biotechnology

The leaf chemistry has been studied in some detail because the plant is drunk as a daily tea across northern China. The flavonoids hyperoside and isoquercitrin dominate, with rutin, quercetin and kaempferol glycosides alongside, and these are the compounds credited with the mild hypotensive effect that made the tea popular. There is also a body of work on the leaf polysaccharides, on chlorogenic acid, and on the volatile fraction. Trials in animals and small human studies report modest reductions in blood pressure and improvements in lipid profiles, though the evidence base is far thinner than the market for the tea would suggest.

The most important chemical point is a negative one. Apocynum venetum does not contain the cardiac glycosides that make its American relative Apocynum cannabinum dangerous, and this distinction is the reason the Chinese leaf can be drunk while the American root cannot. The two are frequently confused in English-language sources, and the confusion has caused real poisoning. Work on the species also covers its salt tolerance, where ion compartmentation in vacuoles and the maintenance of leaf turgor under high sodium load have been described, and its drought physiology, which combines a deep root system with stomatal control that closes early in the day.

Uses & Benefits

The leaf is the commercial product, sold as Luobuma tea, either loose or in bags, and it makes a mild, slightly sweet infusion with a hay-like aroma. It is taken for blood pressure and for general cardiovascular comfort, usually one or two cups a day over months. Anyone on antihypertensive medication should treat it as a possible additive rather than a substitute, and should tell their doctor, because the combination can drop pressure further than intended. It is not appropriate during pregnancy. The fibre is the second product, harvested from the stems in autumn, retted and spun.

As a garden plant, Luobuma is a useful subject for the dry, salty, wind-scoured ground that defeats almost everything else. It is hardy, tolerant of both drought and winter cold, and it will grow where the soil is alkaline and poor. Its creeping habit means it wants room, or a root barrier, and it is best used as a ground-covering colony on a bank or a rough piece of ground rather than as a specimen in a border. The pink summer flowers are small but numerous, and bees work them steadily. In China it is planted deliberately for saline land reclamation and for stabilising the edges of irrigation channels.

Growing from Seed

The seed is small and light, and it germinates best on the surface. Fill a tray with a light mix of loam, sand and a little peat or coir, firm it, scatter the seed thinly, and press it down without covering it, because light is required. Water from below or with a fine mist, cover with glass or a clear lid to hold humidity, and keep the tray warm and bright. Germination begins in about ten days and continues for a month, unevenly. As soon as the seedlings have two true leaves they need full light and good air, or they stretch and damp off.

Prick them out into deep pots, since the root goes down fast, and grow them on in a cool, bright frame. Plant out in spring once the risk of hard frost has passed, into full sun and any well-drained soil, including saline and alkaline ground. Water through the first summer, then leave the plants alone. Once the rhizome begins to run, the colony expands quickly and can be lifted and divided in early spring if it oversteps its bounds.

Our Take

Luobuma is a plant of the margins, and it grows best when treated as one. Give it sun, poor ground and room to run, and it will give back tea, fibre and a colony of pink flowers in the driest corner of the garden.

Herb Seeds