Kigelia africana (Lam.) Benth.

Bignoniaceae, Sally Bidgood, Bernard Verdcourt, Kaj Vollesen. Cobaeaceae, Bernard Verdcourt. Flora of Tropical East Africa. 2006

Type

Type: Senegal, Adanson 199A (P-JUSS 4991, holo.; microfiche!) (Note: * Several authors have suggested Thouin was the collector because Lamarck mentions him but Thouin was a gardener at the Jardin des Plantes in Paris and he never went to Africa; he was a friend of Adanson and possibly received material from him.)

Morphology General Habit

Shrub 2–3 m tall or tree often with wide spreading crown, 2.5–18(–24) m tall and possibly larger (but reports of up to 35 m incorrect).

Morphology General Bark

Bark usually grey, occasionally brown, smooth to rough or ridged, scaly or flaking.

Morphology Leaves

Leaves opposite or ternate.

Morphology Leaves Leaflets

Leaflets thin to very coriaceous, (2–)3–8-jugate, oblong, elliptic, ovate or obovate, (6–)10–20(–30) × (4–)6–13(–16) cm, acute to cuneate or rounded, truncate, or emarginate at the base, entire to serrate (particularly sucker shoots), rounded, obtuse or acute to distinctly acuminate at the apex, glabrous to pubescent or tomentellous, smooth or often slightly to very scabrid with raised pale dots, peltate and punctate glands sometimes present; venation plane or sometimes raised or impressed, with 7–12 pairs of veins.

Morphology Reproductive morphology Flowers

Flowers said to smell unpleasant, in lax terminal hanging panicles 30–80(–150) cm long including peduncle up to 40 cm long.

Morphology Reproductive morphology Inflorescences Bracts

Bracts lanceolate, 1 cm long.

Morphology Reproductive morphology Inflorescences

Individual cymes 1–3flowered.

Morphology Reproductive morphology Flowers Pedicel

Pedicels hooked, 1–4(–5) cm long.

Morphology Reproductive morphology Flowers Calyx

Calyx campanulate, 2–5 cm long, ± 2–lipped, irregularly lobed, the lobes ± 1 cm long, tomentose to glabrous, with scattered glands.

Morphology Reproductive morphology Flowers Corolla

Corolla at first with tube yellow outside, turning orange or red and with dark red to blackish inside, 3–9 cm long, cylindrical at base for a very variable length; lobes yellow-green outside suffused with crimson, dark crimson inside, ± ovate, 3–4.5 cm long and wide.

Morphology Reproductive morphology Fruits

Fruits cylindrical, 30–90 cm long, 7.5–10 cm wide, tough and woody; stalks up to 50 cm long.

Morphology Reproductive morphology Seeds

Seeds ovoid, ± 11 mm long, 7 mm wide and 4 mm thick.

Figures

Fig. 11, p. 45.

M. Thulin et al. Flora of Somalia, Vol. 1-4 [updated 2008] https://plants.jstor.org/collection/FLOS

Morphology General Habit

Tree, up to 20 m tall

Morphology Leaves

Leaves 12–30 cm long; petiole 3–6 cm long; leaflets 5–7, the terminal one with 1–4 cm long petiolule, the others sessile or subsessile; blade of leaflets 2–15 x 2–8 cm, oblong to elliptic or obovate, ± asymmetric at the base, mucronate to acuminate or truncate to retuse at the apex, with undulate to dentate margin, with 5–10 pairs of lateral nerves, puberulous to glabrous

Morphology Reproductive morphology Inflorescences

Panicles 0.3–1(–1.5) m long; pedicels 1–7 cm long, upcurved at the tip

Morphology Reproductive morphology Flowers Calyx

Calyx 2.5–4.5 cm long

Morphology Reproductive morphology Flowers Corolla

Corolla 6–10 cm long, at first yellowish, later reddish to purplish, with darker streaks inside and outside; tube 2–4 cm long, abruptly widening upwards; lobes ± rounded, c. 3 cm wide

Morphology Reproductive morphology Flowers Androecium Stamens

Filaments 3.5–5.5 cm long; anthers 0.5–1 cm long

Morphology Reproductive morphology Flowers Disc

Disk c. 1 cm in diam., irregularly lobed

Morphology Reproductive morphology Flowers Gynoecium Style

Style up to 8 cm long

Morphology Reproductive morphology Fruits

Fruit up to 80 x 13 cm, greyish-ochraceous

Morphology Reproductive morphology Seeds

Seeds c. 10 x 7 mm.

Distribution

S1–3 widespread in tropical Africa.

Ecology

Altitude range 0–400 m.

Vernacular

Bakaroor, barde, berde, sag (Somali).

Note

This species is very variable in, for example, habit and leaf morphology.

Kew Species Profiles

General Description

The sausage tree is sacred to many African communities and has a wide variety of uses in traditional and Western medicine, including commercially available skin lotions.

Kigelia africana is an African tree, easily recognised due to the large sausage-shaped fruits hanging from its branches. The generic name Kigelia comes from the Mozambican name for sausage tree, 'kigeli-keia'. Sausage trees are sacred to many communities and are often protected when other forest trees are cut down. In Kenya, the Luo and Luhya people bury a fruit to symbolise the body of a lost person believed to be dead.

The flowers only open at night and are pollinated by bats and hawk-moths. They are dark red, which is unusual for a bat-pollinated species (bats are normally attracted to white flowers), but the strong unpleasant smell of the flowers is thought to attract bats.

Every part of the tree is used in herbal medicines (eg for digestive and respiratory disorders, and to treat infections and wounds). The sausage tree is used in a variety of commercial applications to treat skin complaints. Research into its anti-bacterial, anti-fungal and anti-tumour activity is ongoing.

Species Profile

Geography and distribution

The sausage tree is found across sub-Saharan tropical Africa and as far south as South Africa. It is cultivated in other tropical countries and is used as an ornamental tree in Australia, the USA and parts of South-East Asia.

Description

Kigelia africana is a tree, 2.5-18 m tall, or sometimes a shrub 2-3 m tall. The bark is smooth and grey-brown in colour. The leaves are in groups of three at the ends of the branches and are 10-20 cm long with 3-8 leaflets. The inflorescence is a panicle, 30-80 cm long. The tubular flowers are dark red with yellow veins, and have an unpleasant smell. The fruits are sausage-shaped, 30-90 cm long and 7.5-10 cm in diameter.

The sausage tree is very variable in habit and leaf morphology. Trees growing in forests have larger leaflets than trees growing in open areas. It was once thought that there were ten different species of Kigelia , but botanists now recognise only one. In East Africa two subspecies are recognised, K. africana subsp. africana growing in grasslands and woodlands and K. africana subsp. moosa in tropical forests.

Multiple names

A comprehensive collation of data on sausage tree has been made by Kew's Survey of Economic Plants for Arid and Semi-Arid Lands (SEPASAL).

Apart from detailed information on uses throughout Africa, the SEPASAL database (available online) also records over 400 vernacular names by which the sausage tree is known - an indication of the tree's importance and value to communities throughout its geographic range.

Threats and conservation

The sausage tree is widespread across tropical Africa. It is a sacred tree for many communities and is usually protected on farm lands when other tree species are cut down. In Malawi, Kigelia africana is now protected after many trees were cut down to make canoes.

Uses

Kigelia africana is an important tree for many people and has a wide range of uses.

Both ripe and unripe fruits are poisonous to humans but the fruits can be dried and fermented, and used along with the bark to enhance the flavour of traditional beers. The seeds are sometimes roasted and eaten in times of food shortage.  The wood makes good quality timber for fences, planking, boxes and canoes.

Kigelia africana is a suitable tree for planting to stabilise riverbanks, while its broad canopy makes it a good shade tree in the open savanna. It is, however, not advisable to park a vehicle or to sit beneath a fruiting tree - the 'sausages' (fruits) can weigh up to 12 kg and can cause considerable damage when they fall!

Millennium Seed Bank: Seed storage

The Millennium Seed Bank Partnership aims to save plant life worldwide, focusing on plants under threat and those of most use in the future. Seeds are dried, packaged and stored at a sub-zero temperature in our seed bank vault.

Two collections of sausage tree seeds are held in Kew's Millennium Seed Bank based at Wakehurst in West Sussex.

For further information on Kigelia africana seeds see Kew's Seed Information Database

Sausage tree at Kew

The sausage tree can be seen growing in the Palm House and the Princess of Wales Conservatory.

Dried and spirit-preserved specimens of Kigelia africana are held in the Herbarium, one of the behind-the-scenes areas of Kew. Details, including images, of some of these specimens can be seen on-line in the Herbarium Catalogue.

Bark, fruits, seeds and wood from K. africana are also held in the Economic Botany Collection. These specimens are made available to researchers from around the world by appointment.

Ecology

Riverine forest, wooded grassland, savanna and forest margins.

Conservation

Least Concern (LC) in the Red List of South African Plants.

Hazards

Both ripe and unripe fruits are toxic to humans and can also do considerable damage if they fall on vehicles or unsuspecting humans.

Bignoniaceae, M. A. Diniz. Flora Zambesiaca 8:3. 1988

Morphology General Habit

Medium or large sized tree up to 25 m. tall.

Morphology Leaves

Leaves opposite or in whorls of 3, imparipinnate, crowded towards the tops of the branches; leaflets (1) 2–5-jugate, sessile or subsessile, except the terminal ones with petiolule (0.7)1–4(6.5) cm., long; leaflet lamina 3.5–17.5 (22.5) x 2.5–11 cm., ovate elliptic, obovate to rounded, apex obtuse, broadly tapering to rounded or retuse ana not so often apiculate, base rounded to cuneate, slightly to profoundly asymmetric except in the terminal leaflet which is asymmetric, glabrous to more or less hairy in both surfaces sometimes more roughly hairy in the superior one, papyraceous to coriaceous, margins entire, serrate or toothed and sometimes conspicously wavy; lateral nerves (4)6–13 pairs impressed above, prominent below, venation laxly reticulate; petiole (2)3.5–14(16) cm. long; rhachis 3–25 (29) cm. long, sulcate above, terete below.

Morphology Reproductive morphology Flowers

Flowers in pendulous very lax, terminal panicles, 30–100 (150) cm. long, longly pedunculate; pedicels 1–11 (13.5) cm. long, upcurved at the tip; bracts small lanceolate caducous.

Morphology Reproductive morphology Flowers Calyx

Calyx shortly tubular to campanulate, (1.7)2–4.3 cm. long, irregularly 4–5 lobed with the lobes up to 1 cm. long, ribbed, glabrous to sparsely puberlous outside, sometimes with irregularly scattered small glands.

Morphology Reproductive morphology Flowers Corolla

Corolla large, 6–12 cm. long, widely cup-shaped, at first yellowish, later becoming reddish to purplish, streaked darker inside and outside, glabrous except sometimes at the point where the filaments become free; limb bilabiate, the superior lip bilobed, the lower one 3-lobed and recurved, lobes more or less rounded; corolla tube cylindrical at the base and suddenly widening and incurving upwards.

Morphology Reproductive morphology Flowers Androecium Stamens

Stamen-filament 3.5–6.5 cm. long, adnate up to 1–2.5 cm. from the base of the corolla tube; anthers 7–13 mm. long; staminode rather large.

Morphology Reproductive morphology Flowers Disc

Disk c. 1 cm. in diam. 2–3 mm. high, fleshy, irregularly lobed, sometimes almost truncate.

Morphology Reproductive morphology Flowers Gynoecium Ovary

Ovary 8–15 mm. long, cylindrical; style 4–7(8) cm. long, filiform.

Morphology Reproductive morphology Fruits

Fruit sausage-shaped up to 1 m. long and 18 cm. in diam., pendulous from a long peduncle, greyish-brown, lenticellate in the youth, massive, wood-walled, indehiscent.

Morphology Reproductive morphology Seeds

Seeds 10 x 7 mm. numerous, wingless, embedded in a fibrous pulp; testa coriaceous; cotyledons folded.

Bernal, R., Gradstein, S.R. & Celis, M. (eds.). 2015. Catálogo de plantas y líquenes de Colombia. Instituto de Ciencias Naturales, Universidad Nacional de Colombia, Bogotá. http://catalogoplantasdecolombia.unal.edu.co

Distribution

Cultivada en Colombia; Andes.

Morphology General Habit

Árbol