Scrophularia ningpoensis Seeds | Ningpo Figwort
LATIN NAME: Scrophularia ningpoensis
COMMON NAME: Ningpo Figwort, Chinese Figwort
Plant Profile
Scrophularia ningpoensis is a robust perennial herb of moist ground, rising to a metre or more from a cluster of thick fleshy roots, with four-angled stems, opposite leaves and a long season of small flowers in loose branched clusters. It comes from the damp meadows and stream margins of eastern China, and it wants the same in a garden: soil that stays moist, shade from the hottest sun, and room for the roots to swell.
The corolla is a short tube with two lips, the upper split into two lobes and the lower into three, and the flower is a dull brownish-purple or greenish, which is not a colour that sells plants but is precisely what wasps find. Four fertile stamens arch over the mouth; the fifth is reduced to a flattened spoon-shaped staminode fixed under the upper lip. Wasps pollinate the genus, and the staminode appears to work as a brace that keeps the insect oriented as it reaches the nectar.
The stems are square in section and smooth, the leaves ovate to lance-shaped and sharply toothed, and the flowers give way to small dry capsules holding a great many fine dark seeds. When the stems die back and dry, the capsules split at the top and the seeds rattle out on the wind.
The value of the root lies in a family of bitter compounds, and the chemistry explains why it tastes the way it does.
Because a field crop takes a whole season to produce a root, tissue culture has been explored across the iridoid-producing families as an alternative: shoot cultures from nodal and shoot-tip explants, and hairy-root cultures induced with Agrobacterium rhizogenes have been used experimentally as a source of the same class of compounds, and micropropagation of Scrophularia species from shoot tips is well established.
Science & Biotechnology
The roots, and to a lesser degree the leaves, carry iridoid glycosides, notably harpagoside and harpagide, with aucubin, catalpol and phenylpropanoid glycosides such as acteoside filling out the mixture. These compounds are built from geraniol by a route characterised in detail in other iridoid-producing plants: geraniol is oxidised and then cyclised, and iridoid synthase, the enzyme that closes the ring, gives the family its name.
Uses & Benefits
Two crops come off this plant: a root traded for centuries, and a border perennial that most gardeners have never tried.
The species takes its name from the district where the root was traded, and the crop is grown in eastern and central China for the thick fleshy roots, which are lifted in autumn after the tops die down, cleaned and dried, some grades being steamed first so the slices come out blackish and slightly glossy. The dried slices are the article of commerce and have been part of the Chinese materia medica for a very long time, used in compounds rather than alone.
As a garden plant, Chinese figwort is worth a place at the back of a moist border or beside a pond, where the tall stems and small brownish flowers go unregarded until the wasps arrive. It flowers through late summer into autumn, when tall perennials are scarce.
Growing from Seed
The seed is fine and the plant is thirsty, so the soil matters more than anything done above ground.
Fill a pan with a moisture-retentive compost, firm it, and sow the seed thinly on the surface before covering it with no more than 2 mm of sieved compost or fine grit, because the seed needs light and moisture together. Stand the pan in water until the surface glistens, then keep it in light shade and never let the surface dry out. Thin the seedlings out with tweezers as soon as they can be handled.
Prick the seedlings out at the two-true-leaf stage into individual pots of a humus-rich compost. Pot on at about 8 cm, plant out at 20 to 25 cm, and water regularly through the first summer, because a dry root zone in the establishment year is what kills figwort. A clump several seasons old is best lifted in early spring and divided, resetting the smaller offsets.
Our Take
Grow this one for the wasps and the damp ground rather than for a vase, and give it room, because it will seed along a wet ditch. Its closest relative in the trade is Scrophularia buergeriana, which wants the same conditions and roots up a little smaller. If you like the family for flowers rather than for roots, a mullein is the dramatic summer counterpart, and a patch of purple foxglove will seed into the same moist shade. Keep the ground wet, lift the roots after the tops have died back, and the clump will renew itself.
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