Cornus officinalis Seeds | Fructus Corni Pagoda Dogwood Shan Zhu Yu
LATIN NAME: Cornus officinalis
COMMON NAME: Cornelian Cherry Dogwood
Plant Profile
Cornus officinalis is a small tree of the dogwood family, four to ten metres tall, with opposite oval leaves and clusters of small yellow flowers that open in March before the leaves. The fruit is a scarlet drupe about fifteen millimetres long, ripening in October and hanging in loose clusters.
It is native to the woods of Shaanxi, Henan and Zhejiang, and has been cultivated in China since the Han dynasty. The dried fruit, shan zhu yu, is one of the most widely used tonic herbs in the country, and the tree is also planted as an ornamental for its spring flower and autumn colour. The wood is hard and close-grained, and old trees are sometimes grown for timber as well as fruit.
Science & Biotechnology
The fruit is dominated by iridoid glycosides, chiefly loganin and morroniside, with cornuside and a small amount of ursolic acid. Loganin inhibits inflammatory signalling in several cell models and has been studied for its effect on podocytes, the cells that filter blood in the kidney.
Most of that work is rodent-based, in streptozotocin-diabetic models, and it is presented as a mechanism rather than as proof of clinical benefit. There is a small human literature on diabetic nephropathy in combination formulas, which cannot separate the effect of one herb. The fruit is also strongly astringent, from tannins, which is the basis of its traditional use in diarrhoea.
Uses & Benefits
Dried fruit is decocted at six to twelve grams, alone or, more often, as a component of Liuwei Dihuang Wan, the six-ingredient formula built around it. The taste is sour, slightly bitter and drying.
Traditional practice avoids it during acute infection with fever, and it is not given where there is damp-heat, because the astringency is thought to trap the condition. No serious toxicity is reported at normal doses; the main risk is that a tonic is taken for years without a reason. Powdered fruit is also stirred into congee in autumn, a food use rather than a prescription.
Growing from Seed
Seed has a double dormancy and will not sprout from a spring sowing. Give it four months of warm, moist conditions at 20 to 25°C, then three to four months at 2 to 5°C, and expect germination around forty per cent in the second spring.
Grafting or budding onto a seedling rootstock is the commercial route and the way to keep a good fruiting form. Trees begin to crop at four or five years and yield three to five kilograms at maturity. They take sun or half shade and any reasonable soil, and the fruit is picked when fully dark red, in late October. Fruit set is better with a second tree nearby, though a single specimen will still crop.
Our Take
A handsome small tree that earns its place in the garden on flower and colour alone, with a fruit that has a long record and a modest evidence base.
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