Common name: Sea holly, Holly-leaved acanthus, Holly mangrove, Krishnasaireyaka, Karimkurunji, Painaschulli, Payinnachulli, Chullikandal, Harikasa
Sea holly plants are commonly seen near marshes, backwaters, rivers, and swamps, even in areas with very high salinity. The plant can remove excess salt through leaf pores, thus helping it survive and thrive in saline water bodies.
They can grow to a height of 1-2 meters with long erect stems that might slant to the side when they are very long. Leaves resemble holly leaves, dark green and thorny. Thorns are present on the sides of the leaves and also at the base, near the stem. Sea holly leaves are 8-12 cms long, having wing-like lobes ending in sharp spines.
The plant flowers from December to May with lovely, lilac-colored flowers in large bunches at the tip of the stems. Each bunch contains over 15 flowers, making the plant a beautiful sight during this time. Compared to the prickly, harsh-looking plant, the flowers are tender and beautiful with a large petal that folds backward revealing hairy stamens and style.
These bright flowers of Sea holly plants attract birds, bees, butterflies, and other insects that help pollinate them. After pollination, the plant produces green, oval-shaped fruits that contain 4 seeds. The fruits burst open on maturity, releasing the seeds over 2 meters away from the plant.
This explosive method of seed dispersal plus higher chances of water dispersal helps the plant establish itself in new territories. Its spiny foliage makes it difficult to get rid of these plants completely, and they are hence considered invasive weeds in many parts of the world.
Sea holly plants grow well in full sun, but they can also tolerate partial shade. Leaves growing in complete shade tend to lose the spines on their leaves.
Sea holly plants have many medicinal uses in Indian and Chinese medicine, in the treatment of rheumatism, asthma, colic, stomach ailments, wounds, insect bites, sore legs, joint pains, fever, and paralysis.
Parts of the plant are used for making soap. They can make good border or fence plants since the thorny foliage will prevent animals from crossing it. Though it might also become a pain to get rid of them later.
Propagation is through seeds and stem cuttings.