- Decaisnea Lindl. is a synonym of Tropidia, an orchid genus.
Hook.f. & Thomson
The genus comprises one or two species, depending on taxonomic opinion. Decaisnea insignis (Griffith) Hook.f. & Thomson was described from Nepal, and is sometimes restricted to the plants occurring in the Himalaya, with Chinese plants distinguished as Decaisnea fargesii Franchet. The only cited distinction between the plants from the two regions is the fruit colour, yellow-green in D. insignis and bluish in D. fargesii. This is of little significance and the two are now combined under the older name D. insignis by some authors.
Decaisnea are deciduous shrubs or small trees growing to 5 to 8 meters tall with trunks up to 20 centimeters in diameter. The leaves are pinnate, 60 to 90 cm long, with up to 25 leaflets each up to 15 cm long and 10 cm broad. The flowers are produced in drooping panicles 25 to 50 cm long. Each flower is 3 to 6 cm wide with greenish-yellow sepals and no petals. The fruit is a soft greenish-yellow to blue-black pod-like follicle up to 10 cm long and 3 cm diameter. It contains a transparent, glutinous, jelly-like pulp containing numerous flat black seeds about a centimeter wide. The pulp is edible. The flavor of D. fargesii fruit pulp has been described as sweet and similar to watermelon, and the texture described as "gelatinous". D. insignis fruit has been described as "bland" and jelly-like.
Cultivation and uses
Decaisnea is grown as an ornamental plant for its foliage and decorative fruit, bright blue in many cultivated specimens. Most plants in cultivation derive from Chinese seed and are commonly grown under the name D. fargesii. The plants are successfully grown in cooler temperate climates, and in fertile, well-drained soil. They are tolerant of temperatures as low as -15°C (5°F).
- Bean, W. J. (1973). Trees and Shrubs Hardy in the British Isles. John Murray.
- Rushforth, K. D. Trees of Britain and Europe. HarperCollins.
- Decaisnea. Flora of China.
- Levine, K. Plant Profiles: Decaisnea fargesii. Talking Plants. National Public Radio, Washington, D.C. 2003.
- Botany Photo of the Day: Decaisnea insignis. UBC Botanical Garden and Centre for Plant Research.
- Decaisnea fargesii. Missouri Botanical Garden.