Scientific Name : Kigelia africana (Lam.) Benth.
Common Name : Sausage Tree, Cucumber Tree
Chinese Name : 吊瓜樹, 吊燈樹
Family : BIGNONIACEAE
Local distribution status : Exotic species
| Origins | Countries of Africa, such as Ethiopia, Niger and Uganda. |
|---|---|
| Ecology |
Blossoming is not only confined to daytime. For plants which blossom at night, it is pivotal for them to equip alternative reproductive strategies for aligning with the behaviours of nocturnal pollinators. Here, Sausage Tree has developed an intriguing mutualistic relationship with bats. Bat species (e.g. fruit bat) are only active at night; they are sizable mammals with generally reduced visual acuity but with compensated superb olfactory acuity. Floral colour could be trivial to highlight flowers to bats; therefore, Sausage Tree has evolved brilliantly to produce nectar with chemical signals (e.g. isoamyl acetate) which can be deciphered by bats. The flowers have developed into larger mouths and stiffer pedicles which can hold a bat and allow it to access the inside nectar. The flowers blossom at night with short duration, often falling off before next afternoon. Although birds could be potential pollinators, they are far less effective than bats and other nocturnal animals due to the floral abscission. The fruits are large and weighty. Without any aid of large animals (e.g. elephants), the fruits is restricted to gravity, which only confers a close dispersal distance from the maternal tree. |
| Application |
The fruits are medicinally effective for relieving digestive system disorders. The seeds are esculent and always baked for food by the locals. In Africa, the fruits are common charms for praying better crop yields, fecundity, wealth and prosperity. Sausage Tree is introduced as roadside or ornamental trees by virtue of its extensive tree crown, flamboyant flowers and majestic sausage-like fruits. The fruits are weighty (to 10 kg) but can incredibly cling to the branches for a long time. However, they are still dangerous from which the fruits falling off can be dramatically violent. The planting framework of the tree should be carefully established to avert compromising the safety of human property. In Hong Kong, a Sausage Tree is registered as an old and valuable tree (OVT) in the City Hall Memorial Garden (LCSD CW/124), measured with DBH at 850 mm, height at 14 m and crown spread at 16 m. |
| Meanings of name | The generic name Kigelia is derived from kigeli keia, the Mozambique vernacular of how the natives refers to this genus. The specific epithet Africana means from Africa. In respect of its giant sausage-like ellipsoid fruits unexpectedly hanging on the branches, the tree is thus given the names ‘Sausage Tree’ and ‘吊瓜樹’. |
| Growing habit | Evergreen tree. |
|---|---|
| Height | To 25 m. |
| Stem | Bark rough, greyish brown, thinly flaky. |
| Leaves | Imparipinnately compound, opposite or 3-4 in a whorl, leaflets 7-9 pairs, opposite. Blade glabrous, elliptic to oblong, apex cuspidate, base cuneate, entire, lateral veins predominant. |
| Flower | Panicles terminal at the end of branches, pendulous, flowers 6-10. Flowers large, scarlet, calyx campanulate, corolla funnelform, blooming in the evening, pungent. |
| Fruit | Capsules sausage-shaped, heavy, fruit closed indehiscent, woody, brownish yellow at maturity, seeds many. |
| Flowering period | -unknown |
| Fruiting period | -unknown |
Scientific name above is based on Hong Kong Herbarium website :
https://www.herbarium.gov.hk/en/hk-plant-database/plant-detail/index.html?pType=species&oID=11105
Scientific names from other databases :
― GBIF : Kigelia africana (Lam.) Benth.
― Plants of the World Online : Kigelia africana (Lam.) Benth.