Sophora alopecuroides Seeds | Foxtail Sophora
LATIN NAME: Sophora alopecuroides
COMMON NAME: Foxtail Sophora
Plant Profile
Foxtail sophora is a clumping, herbaceous perennial of the pea family, native to the dry steppes of northern China, Mongolia and Central Asia. It dies back to the ground each winter and sends up stout stems forty to a hundred centimetres tall in spring, clothed in grey-green pinnate leaves and topped by dense, upright spikes of creamy-white flowers.
The pods that follow are deeply constricted between the seeds, so that each looks like a string of beads, and the whole cluster resembles a fox’s brush. The plant spreads by woody rhizomes that creep through sandy soil, and a patch once established is very hard to dig out. Every part is bitter, and the roots smell faintly of liquorice when they are broken.
Science & Biotechnology
The plant is a reservoir of quinolizidine alkaloids, chiefly matrine, oxymatrine and sophoridine, which make it unpalatable to stock and toxic if grazed in quantity. Those same compounds are the reason it is studied: matrine has been investigated as an anti-inflammatory and antiviral agent, and sophoridine has been through clinical trials in China as an antitumour drug.
Sophora alopecuroides is also a serious rangeland weed. It was introduced to western North America in the early twentieth century and has spread through irrigated pasture and river bottoms, where it forms dense stands that cattle will not eat. It is drought-tolerant, salt-tolerant and avoided by insects, which leaves it with few natural controls outside its native range.
Uses & Benefits
In Chinese practice the seed is known as ku dou zi and the whole plant is used in decoctions, but it is a professional medicine rather than a domestic herb: the therapeutic dose and the toxic dose are close, and cases of poisoning from home preparations are recorded. The alkaloid extracts are used in agriculture as a botanical insecticide against aphids and caterpillars.
In a garden it is grown as a drought plant for a hot, dry bank, where its grey foliage and pale spikes last through the summer. It is also useful for stabilising sand and for covering ground that nothing else will hold. It should be kept away from grazing land, and the seed should not be allowed to scatter into pasture, since the plant spreads by both rhizome and seed.
Growing from Seed
The seed has a hard coat and germinates unevenly. Nick the surface with sandpaper or soak it in warm water for a day before sowing, then sow two centimetres deep in a sandy mix at 20-25 °C. Seedlings appear in two to four weeks, and a proportion may wait until the following spring.
Plant out in full sun in poor, sharp-draining soil, and water only until the roots are down. The plant fixes nitrogen, so it needs no feeding, and it resents rich ground, which makes it lax and leafy. Cut the old stems to the ground in late winter. To keep it in bounds, lift the rhizomes at the edge of the clump each autumn, since digging is more effective than pulling.
Our Take
A steppe perennial with handsome pale spikes and a serious alkaloid chemistry. Grow it on a dry bank, and keep it away from livestock and from the vegetable garden.
Related Reading
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