Gentiana scabra var. buerugeri (Japanese gentian, "Rindo")

Japanese name: リンドウ （竜胆）
Scientific name: Gentiana scabra var. buerugeri

[Overview]
A perennial 20–100 cm tall, found in sunny, slightly moist hills and fields.
It has a slender rhizome underground.
The stem is erect or ascending.
Leaves are simple and opposite, ovate-lanceolate, 3–8 cm long, with three conspicuous veins.
The leaves on the lower part of the stem form scale-like sheaths.
The leaf margins are not wavy like those of Asama-rindo, but are characteristically rough, with fine projections.
There is no leaf stalk.
The flowers are solitary at the stem tip or in the upper leaf axils, and have bracts.
The corolla is tubular-bell-shaped, 4–5 cm long, 5-lobed at the tip, and purple, with brown spots on the inside of the corolla tube.
Appendages develop between the corolla lobes, and there are nectaries at the base of the ovary.
The calyx tube is 1–2 cm long, and the calyx lobes are lanceolate-linear and do not spread flat.
The flowers face upward and open only on sunny days.
The fruit is a capsule.

[Uses]
The roots and rhizomes are used medicinally.

[Cultivation]
Propagate from seed, by division, or by stem cuttings.
The best time for stem cuttings is May–June.
It prefers a fertile soil that is sunny, well drained, moisture-retentive and well aerated.
Direct summer sun causes leaf scorch, so move potted plants to bright shade, and shade plants in the ground by 50%.
It is cold-hardy, but in winter it is best to protect it with a straw mulch or similar so that it is not exposed to hard freezing or cold wind.
It dislikes dryness and the leaves are damaged when it dries out, so water once a day, in summer in the evening when the temperature drops.
However, if it becomes too wet, the roots will rot.
If fertilizer is lacking, the leaves turn yellow.
Apply slow-release fertilizer as a base fertilizer, and apply liquid fertilizer twice a month in spring and autumn.
Leaving spent flowers in place tires the plant, so remove them if you are not collecting seed.
Pests and diseases include rust, root-knot nematodes and aphids.

[Notes]
Most of what is called "rindo" in cut flowers and the like are improved cultivars of Ezo-rindo.
Ezo-rindo grows in wetlands and similar places north of central Honshu, has a thick rhizome, and its leaf margins are not rough like those of Rindo.

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