Taxonomy and distribution of species of the genus Acanthus (Acanthaceae) in mangroves of the Andaman and Nicobar Islands, India

Abstract

A recent floristic survey revealed the occurrence of three species of Acanthus in mangroves of the Andaman and Nicobar Islands, India. Of these Acanthus ilicifolius and A. ebracteatus are shrubs, whereas A. volubilis is a climbing shrub. All the three Acanthus species were recorded from the Andaman Islands, but only A. ilicifolius from the Nicobar Islands. A. volubilis is easily distinguished from other two species by its unarmed and twining delicate sprawling stems, un-serrated elliptical leaves, white corolla and absence of bracteoles. A. ilicifolius and A. ebracteatus are differentiated based on the presence and absences of bracteoles, corolla color, and position of Inflorescence and direction of stem axial spines. A key for the species of Acanthus of the Andaman and Nicobar Islands is also provided.

Ethnomedicinal, Phytochemical, and Pharmacological Aspects of Genus Acanthus

“…The plant is a shrub, height up to 3 m green, light green or purple, stem thick, branched, roots rarely above ground leaves simple, opposite, lanceolate to broadly lanceolate, leaf margin spiny/dentate, leaf tip acute, petiole low length ca 0.5-2 cm long, inflorescences terminal [15].…”

“…In Southeast Asia plant has found in Cambodia, Myanmar, the Philippines, Vietnam, Malaysia, Singapore, Indonesia and Papua New Guinea; in India, it has recorded in Kerala, Puducherry, and ANI [15].…”

“…India, Andaman and Nicobar Islands, South Andaman, Sippighat (P. Ragavan, PBL 30969 and 30970) [15].…”

“…Plant is a twisted shrub up to ~2-4 m tall; stem slim, soft, green, branched, axial spines lacking; roots rarely above ground/prop roots on lower parts of reclining stem; leaves simple, opposite, spines absent, juicy, elliptic/oblong-lanceolate, leaf tip acute to obtuse with spin, leaf margin spines lacking, petiole low length ca 0.5-2 cm long, green; inflorescence terminal; style surrounded by stamens; ovary bilocular [15].…”

“…Sri Lanka and the Andaman Islands, to Myanmar, Indonesia, Cambodia, Malaysia, Singapore, Thailand and Papua New Guinea. In India, the plant has found in Odisha, ANI, and Sundarbans [15].…”