BIOLOGICAL CHARACTERISTICS OF Clausena indica (Dalz.) Oliv. IN SELECTED NORTHERN MOUNTAINOUS PROVINCES OF VIETNAM

Abstract

This study evaluated the biological characteristics of 15-year-old Clausena indica (Dalz.) Oliv. grown in three Northern mountainous provinces of Vietnam (Thai Nguyen, Cao Bang and Lang Son) on two representative soil types (ferralitic hill soil and limestone soil). Morphologically, the species is a small evergreen tree with pinnate leaves bearing numerous oil glands; flowers are small, bisexual, with five sepals, five petals, ten stamens, a superior ovary with three locules, and a style 3.2 - 3.3 mm long; fruits are spherical berries (10.8 - 11.8 mm in diameter) with thin pericarps densely covered with oil glands; seeds are ovoid. The size of flowers and fruits varied slightly among sites, whereas the structural characteristics remained stable across regions. In growth performance, trees produced three major shoot flushes (spring, summer and autumn), showing more vigorous growth on limestone soils. Quality indicators, including Ca, K, protein, total sugars, polyphenols, flavonoids, essential oil, vitamin C, and β -carotene, were significantly higher on limestone soils, indicating enhanced mineral uptake and secondary-metabolite biosynthesis under these ecological conditions. The results confirm the species’ high physiological and biochemical plasticity and provide a scientific basis for developing raw-material zones for essential-oil, medicinal, and functional-food production derived from its leaves and fruits in the northern mountainous region of Vietnam.