Sterculia tragacantha
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Sterculia tragacantha Common Names: Star chestnut, karaya gum, Indian
tragacanth Scientific
Classification Kingdom: Plantae Clade: Tracheophytes Clade: Angiosperms Order: Malvales Family: Malvaceae Genus: Sterculia Species: S. tragacantha Binomial Name: Sterculia tragacantha Lindl. Synonyms: Sterculia tomentosa Morphological Description Sterculia tragacantha, known as star chestnut or karaya gum tree, is a deciduous shrub
or tree that typically grows between 5–25 meters tall, occasionally reaching up
to 30 meters in rich soils (Kew Science, 2024). The bole, which can attain a
diameter of 75 cm, is often straight with small, winged buttresses at the base,
covered by a smooth, gray bark that becomes rough, fissured, and flaky with
age, exuding a reddish gum when cut (Tropical Plants Database, 2024). The crown
is small and sparsely branched, bearing large, palmately lobed leaves, 15–30 cm
wide, with 5–7 lobes, a glossy upper surface, and a velvety underside due to
stellate hairs (Burkill, 2000). The small, unisexual flowers, 1–2 cm long, are
arranged in axillary panicles, displaying a yellow to reddish hue with a hairy
interior. Fruits are woody, oblong capsules, 5–10 cm long, covered in stinging
hairs, splitting to reveal 5–8 black, glossy seeds, 1–1.5 cm long. Distribution and Habitat Native to West Tropical
Africa, Sterculia tragacantha extends from Senegal and Gambia through Nigeria and Cameroon
to West Tanzania, Zambia, and northern Angola (Kew Science, 2024). It thrives
in wet tropical biomes, commonly found in evergreen and semi-deciduous forests,
riverine thickets, and along watercourses at elevations up to 1,200 meters
(Tropical Plants Database, 2024). The species prefers well-drained, loamy soils
with a pH of 5.5–7.0 and annual rainfall of 1,000–2,000 mm, though it tolerates
seasonal drought, making it a resilient component of savannah woodlands. Ethnopharmacology Sterculia tragacantha is a valued resource in West African traditional medicine,
with its gum, bark, leaves, and seeds containing bioactive compounds such as
tannins, flavonoids, saponins, and polysaccharides (Ahlidja et al., 2024).
Below are key ethnopharmacological uses supported by research: · Demulcent and Wound Healing: In Ghana, gum is applied to burns and
sores; its polysaccharide content forms a soothing mucilage, with studies
showing enhanced fibroblast proliferation in wound models (Verbeken et al.,
2003). · Antimicrobial Effects: In Nigeria, bark decoctions treat
infections. · Anti-inflammatory: In Senegal, leaf infusions reduce
swelling; aqueous extracts reduced carrageenan-induced edema in rats by 40% at
200 mg/kg, attributed to flavonoids (Ojo et al., 2021). · Gastrointestinal Relief: In Côte d’Ivoire, gum is used for
diarrhea. These uses are bolstered
by its phytochemical richness, with gum karaya containing galacturonic acid and
rhamnose, enhancing its medicinal efficacy (Ahlidja et al., 2024). ⚠ Toxicity Profile: No significant human toxicity is reported
for Sterculia tragacantha when used traditionally. Acute toxicity tests in rats showed
no mortality at 5,000 mg/kg of gum extract, though its partial solubility
limits internal use, potentially causing mild gastrointestinal discomfort at
high doses (Verbeken et al., 2003). The fruit’s stinging hairs can irritate
skin and mucous membranes, requiring careful handling (Burkill, 2000). Additional Uses · Nutritional Value: Young shoots and leaves, rich in protein
(10–15%) and vitamin C (20 mg/100 g), are cooked as vegetables, while roasted
seeds, with 25% oil content, resemble peanuts (Adelakun et al., 2014). · Gum Karaya Industry: The tree produces gum karaya, a commercial
polysaccharide used as a stabilizer in confectionery, cosmetics, and
pharmaceuticals, harvested sustainably in West Africa. · Timber and Fodder: The soft wood (density 0.4 g/cm³) is used
for carvings, and leaves serve as livestock fodder, supporting local
agroforestry (Burkill, 2000). References
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