Acanthus ilicifolius L.

Acanthaceae

Acanthus ilicifolius L., Species Plantarum Edn. 1, 2: 639(1753), Type: "Habitat in India."

Holly Mangrove; Mangrove Holly; Mangrove, Holly-leaved; Holly-leaved Mangrove; Bear's Breech

Usually flowers and fruits as a shrub about 1-1.5 m tall.

Twigs with 2-4 axillary spines at each leaf node, each spine about 5-7 mm long. Leaf blades about 7.5-18.5 x 2.5-5 cm, holly-like (Ilex aquifolium) with about 4 or 5 major spine-tipped lobes on each side of the leaf blade with or without additional minor spine-tipped lobes. The major lateral veins extend to the margins of the leaf blade and then beyond the margins as spines about 2-3 mm long.

Sepals four, two large and two small. Larger sepals 2-lobed at the apex. Lower lip of the corolla 3-lobed and upper lip absent. Corolla about 2.5 cm long. Stamens with thick curved bony filaments. Anthers 1-celled, with stiff white hairs along the sutures. Pollen yellow. Ovary green, glabrous with two superposed ovules in each locule. Style about 17-18 mm long, scarcely notched at the apex.

Capsule about 17-25 mm long. Seeds about 6-9 x 5-6 mm. Testa 2-layered, the outer layer rugose and the inner smooth and transparent. The outer layer could perhaps be interpreted as an aril. Embryo green.

Cotyledons about 14-21 x 18-21 mm, rather thick and fleshy, base auriculate. First pair of leaves with toothed or smooth margins. At the tenth leaf stage: leaf margin armed with spines or pungent points. Stems clothed with purple, slightly raised glands. Seed germination time 27 to 41 days.

Occurs in NT, CYP, NEQ and CEQ. Altitudinal range quite small, at or about sea level. Usually grows close to the sea. Often associated with mangroves. Also occurs in Asia, Malesia and the Pacific islands.

Acanthus ilicifolius L. var. ilicifolius, Prodromus 11: 269(1847). Acanthus ilicifolius var. typica Domin, Bibliotheca Botanica 89(4): 1157(1928).