Katu Ikili

This plant falls under the Acanthaceae family and the 2 most common species can be identified in Sri Lanka.

1. Acanthus Ilicifolius

This is a species that can be seen in mangrove swamps and other wet locations in Sri Lanka, and this is the only fern

This can be seen in all the mangrove ecosystems in Sri Lanka. This is a thorny shrub that grows up to 2m in height. Aerial roots are developed in the lower parts of the stem. Leaves have spiny edges. Flowers can be seen in clusters on an upright spike. They are 3-4cm in length and the flower petals are blue colored. The fruits are non-viviparous.

Acrostichum Aureum leaf has 24-30 pairs of leaflets and some of the larger fronds bear sporangia (reproductive organs) on the upper five to eight pairs of leaflets. These are brown and give the pinnae a felted appearance.

2. Acanthus Volubilis

This plant has the most similar features to Acrostichum Aureum and this is an endangered species in Sri Lanka. This This plant is limited to the mangrove ecosystem in Halawatha – Pambala area. This also grows up to 2m in height. Leaf-blades are smooth, usually without spines. The stem is purplish. Similar to Acanthus Ilicifolius, flowers can be seen in clusters. The flower petals are white.