Hibiscus tiliaceus Seeds | Sea Hibiscus
LATIN NAME: Hibiscus tiliaceus
COMMON NAME: Sea Hibiscus
Plant Profile
Sea hibiscus is one of the most widespread trees of tropical coastlines, and it looks the part: a sprawling, often leaning shrub or small tree, four to ten metres, with a dense crown of broad, heart-shaped, leathery leaves and a trunk that is short, crooked and often rooted in sand just above the tide line.
The flowers open in the morning, wide and cup-shaped, bright yellow with a deep crimson centre, and by afternoon they have turned orange and then dull red before falling. Each lasts a day, but they are produced in such succession that the tree flowers for months. The fruit is a small, five-valved capsule surrounded by the persistent calyx, and the seeds inside are kidney-shaped and buoyant.
Science & Biotechnology
Sea hibiscus is a strand species, and its biology is organised around the sea. The seed floats, tolerates salt water for weeks and germinates readily on a fresh shoreline, which is how the tree reached islands across the Pacific and Indian oceans long before people did. Its leaves are thick and glossy, resist salt spray, and its roots hold sand, which makes it a stabiliser of dunes and a pioneer of disturbed coast.
The flowers are pollinated by bees, and the colour change from yellow to red is a signal that the flower has been visited and its nectar is finished, which concentrates subsequent visits on fresh blooms. The genus has recently been split, and the species is now placed in Talipariti by many authors, though the old name remains in wide use. The wood is light, tough and flexible, and the bark is unusually fibrous even for a mallow.
Uses & Benefits
The bark fibre is the traditional resource: stripped in long ribbons, retted and twisted, it made cordage, fishing line, nets, mats and canoe lashing across the Pacific, and in Hawaii the tree is known as hau and its wood was used for outrigger floats and for the frames of canoes. The wood is too soft for structural work but takes a polish and is used for small carvings.
The tree is planted for shade, for wind protection and for the stabilisation of sandy ground, and it is one of the few ornamentals that will grow right on a beach. It takes clipping well and makes a informal hedge or screen, though it will not tolerate hard frost. The flowers are edible as a garnish, and the leaves have a place in Pacific medicine as a poultice, but neither use is a reason to plant it.
Growing from Seed
The seed coat is hard, so nick it or soak it in warm water for a day before sowing. Sow in a sandy mix at twenty-five to thirty degrees, in bright light, and keep moist; germination is usually fast, within two to four weeks, and fresh seed gives the best results.
The seedlings grow quickly and can be planted out within a year in the tropics, where they will flower in the second or third season. Plant in full sun in sandy or poor soil, with shelter from the strongest wind while the roots establish. The tree is drought-tolerant once established and salt-tolerant throughout, but it is not frost-hardy and will be killed by a hard freeze.
Our Take
A beach tree with a real working history and flowers that change colour by afternoon; warm coasts only. Give it sand, sun and salt wind, and it will ask for nothing else.
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