African Tulip Tree

Overview

African tulip tree (Spathodea campanulata) is widely and commonly known as the African tulip tree, and has been introduced pan-tropically for its ornamental value. It is invasive in many countries, mostly tropical islands in the Pacific, Indian and Caribbean, but also Singapore, Papua New Guinea, and Australia. It is considered an invasive species and a weed in many countries. Where introduced, it invades both abandoned agricultural land and closed forest and has become a weed in abandoned pasture sites, where it may become dominant. However, it also has much utilization as a medicinal plant.

Vernacular Names

Kecrutan (Indonesia), Tulipier du Gabon (French), Kae sàet (Thailand), Amapola (Spanish), Sirit-sirit (Tagalog-Philippines), Huo yan mu (Chinese), Kaenboku (Japanese).

Agroecology

A plant of the tropics, where it is found at elevations up to 2,000 m. The tree is suited to humid conditions and grows well in areas with an even distribution of rainfall, though it will tolerate a dry season of up to six months. Grows best in areas where annual daytime temperatures are within the range of 27 to 30 °C but can tolerate 23 to 34 °C. It prefers a position in full sun, a mean annual rainfall in the range of 1,300 to 2,000 mm, but tolerates 1,000 to 2,400 mm. It grows on a wide variety of sites, from poorly to excessively drained, but prefers fertile, deep, and well-drained loams. Grows best in rich, deep soil, but plants are very tolerant of much poorer conditions.

Morphology

• Roots - taproot with a lot of lateral roots.
• Stem - branches are thick and are marked with small whitish-colored corky spots. Younger branches with small hairs.
• Barks- become hollow, dropping large branches as the tree ages.
• Leaves - opposite or in whorls of 3, imparipinnate, stipules absent, petiole 7–15 cm long, rachis 15–35 cm long.
• Flowers - bisexual, zygomorphic, large and showy; pedicel up to 6 cm long, longer in the lower part of inflorescence than in upper part; calyx spathaceous, 4–8 cm long.
• Fruits - a narrowly ellipsoid woody capsule 15– 27 cm × 3.5–7 cm, blackish-brown, dehiscing by 2 valves, many-seeded.
• Seeds - thin and flat, ca. 1.5 cm × 2 cm, very broadly winged.

Cultivation

• Propagation is mostly by seed. Seeds do not require treatment; they are recalcitrant and their viability is short.
• Cuttings can also be used for propagation, with larger diameter cuttings (up to 10 cm) giving the best results.

Chemical Constituents

Alkaloids, flavonoids, saponins, steroids, terpenoids, tannins, glycoside, sterols, cerebroside, iridoid, ketone, phenols, carboxylic acid, benzyl benzoate, geranyl acetone, β-caryophyllene, farnesyl acetone, aromadendrene, tricosane.

Traditional Medicinal Uses

• Studies have shown antimicrobial, hypoglycemic, antimalarial, wound healing, antifungal, analgesic, anti-inflammatory, nephroprotective, antioxidant, and anticonvulsant properties.
• Extracts of the bark, leaves, and flowers are used to treat malaria, HIV, diabetes mellitus, edema, dysentery, constipation, gastrointestinal disorders, ulcers, skin diseases, wounds, fever, urethral inflammation, liver complaints, and as a poison antidote.
• Cold infusion of leaves is used for urethral inflammation.
• The unopened flower buds contain a sweet, watery liquid that is considered to be tonic.
• The bark is chewed and sprayed over swollen cheeks. The bark may also be boiled in water used for bathing newly born babies to heal body rashes.
• In Africa, the stem bark is used as a paste for wound healing.
• In Cameroon, the plant is used for the treatment of malaria, mental disorders, and hemorrhoids.