Prinsepia uniflora Seeds | Hedge Prinsepia
LATIN NAME: Prinsepia uniflora
COMMON NAME: Hedge Prinsepia
Plant Profile
The old broad family has been re-sorted by molecular data, and Prinsepia came out in a small tribe with the pearl bush and the osoberry. What separates it from the plums is the flowering wood: flowers and fruits sit on short spur shoots that also bear a tuft of leaves, a habit that lets the bush crop close to the branch instead of at the end of long growth.
Leaves on long extension shoots differ from those on the spurs: longer, more slender, often more sharply toothed, so a single bush can look like two species. The fruits are round drupes, dark purple when ripe with a bluish bloom, each holding one pitted stone. The stone is the unit of trade, and the kernel inside is the part that gets used.
The genus was named by John Forbes Royle for the Prinsep family of colonial Calcutta, whose best-known member, James Prinsep, deciphered ancient Indian scripts while running the mint. The species itself was described from north Chinese material in the nineteenth century and has been grown in western collections ever since as a curiosity of the rose family.
Science & Biotechnology
Kernels in this part of Rosaceae are chemically guarded. Seeds of the plum and apricot alliance carry cyanogenic glycosides such as prunasin and amygdalin, which release hydrogen cyanide when the tissue is crushed, and Prinsepia kernels belong to the same chemical tradition. That is why the stone is cracked for a modest quantity of kernel and handled with the caution owed to a bitter apricot kernel.
The kernel is largely fixed oil, dominated by oleic and linoleic acids, while the dark skin of the fruit adds anthocyanins of the cyanidin family. Extraction is a household process in the growing regions: stones are dried, cracked by hand, and the kernels pressed or ground.
Rosaceae is among the best-sequenced plant families, with apple, peach and strawberry as anchors, and the drupe is the trait that ties its tribes together. Because Prinsepia sits in an early-branching tribe, its position lets researchers compare how the fleshy layer and the hard stone were assembled across the family.
Uses & Benefits
Stiff spines on the older wood make a barrier that stock will not push through, and the bush takes clipping well. Plant it on a boundary where a fence would otherwise be needed, and prune after flowering so the spur wood carrying next year’s crop is not cut away.
Gather the fruit when the skin darkens, soften the flesh in water, rub it off and dry the stones in the shade. The stones keep for a long time in a dry jar; crack them as needed, and use the kernel sparingly, since its chemistry matches that of other bitter rose-family kernels.
Growing from Seed
Fresh stones move best after a cold, moist spell and resent drying out completely. Sow in autumn and let winter do the work, or keep pots in a cold frame and watch them as the weather warms.
The bush wants full sun and soil that drains; it survives drought once established and dislikes winter wet far more than cold. Aphids and scale are the usual visitors on soft growth, and canker can enter through pruning wounds, so cut cleanly and stay out of the border when the wood is wet.
Our Take
This bush belongs with the other drought-tolerant fruiting shrubs of the north: Chinese dwarf cherry for a low hedge, Siberian apricot where the ground is stony, and Manchurian rose for summer flowers. None of them needs rich soil, and all of them repay a hard prune.
Related Reading
More species in the same orbit as Hedge Prinsepia: