Decaisnea, which belongs to the Lardizabalaceae plant family, is a genus of flowering plants that includes two species, Decaisnea insignis and Decaisnea fargesii Franchet; the only difference between the two species is that the former produces yellowish-green fruit and the latter bluish fruit. These types of plants are native to Asia, particularly Nepal, Myanmar and China, and to Chile in South America, occurring as deciduous shrubs as well as small trees. They are popular as ornamental plants, particularly the Decaisnea fargesii species, which are more commonly known as Blue Sausage Fruit or Dead Man’s Fingers, on account of the very noticeable and finger-like blue fruits.
In the tree form, Decaisnea plants have multiple stems and slim trunks, and can attain heights of around 26 feet (7.9248 meters). All species have pinnate leaves that are around 36 inches (91.44 cm) long, and have at least two dozen long leaflets each. The plant is deciduous, and the leaves drop off in the winter and the tree becomes dormant. New leaves reappear in the spring, and flowers are produced at the tips of the new shoots.
The flowers comprise of six sepals, there being no petals, and are a bright green in color. The Decaisnea flowers are hermaphroditic, which means the same flower has both male and female organs, and the plant is therefore capable of fertilizing itself. The fruit develops in long pods, and contains a transparent jelly-like pulp. This pulp is edible and has a rather bland taste. It is rich in pectin, a substance that is used to make jams and jellies.
The thin pulp contains a number of flat, black seeds that look rather like water-melon seeds. To propagate the plant, the seeds are best sown in spring; plant propagation may also be carried by using cuttings. These flowering plants can do well in areas of full sunlight as well as in shady areas, but require a loamy, acidic soil if they are to thrive. They need frequent, although not excessive, watering. These plants can tolerate frosty conditions when they have become dormant.
These plants do not require any special care, apart from the usual fertilizing and insecticide applications. It will help to add fertilizers to young plants at least once a month, while once or twice a year is generally sufficient for older plants. Decaisnea plants are susceptible to fungi attacks, particularly in the wet season, so it is a good idea to treat the plants with fungicide from time to time to prevent fungal diseases from taking hold.