About Thespesia populnea (L.) Sol. ex Corrêa
The Portia tree, Thespesia populnea (L.) Sol. ex Corrêa, reaches a height of 6–10 m (20–33 ft), with a trunk diameter of up to 20–30 cm (7+3⁄4–11+3⁄4 in). Its pollen grains are approximately 70 microns in diameter. Thespesia populnea is native to tropical coastlines, adapted for oceanic dispersal and growth in island environments. It occurs on both coasts of Africa, in tropical Asia, northern Australia, the Pacific Islands including Hawaii, the tropical Pacific coast of the Americas from Mexico south to Colombia, the West Indies, and Florida in the United States. Its exact native range is debated: most authorities consider it native only to the Old World tropics, some sources including Plants of the World Online include the Pacific Islands in its native range, and sources such as the IUCN Red List and the USDA also include tropical America in its native range. The IUCN only classifies T. populnea as introduced and invasive in Florida, and it may also be invasive in northern Brazil. Like the related Hibiscus tiliaceus, it was one of the main sources of bast fiber for cordage production and wood for Austronesian outrigger ships and carving. Although the plant's seeds can survive for months on sea currents, no remains of T. populnea have been recovered from Polynesia prior to the Austronesian expansion around 5,000 BP, so some authors regard it as a canoe plant, deliberately carried and introduced by Austronesian voyagers to the islands they settled. However, many other authorities still consider it questionably indigenous to Pacific islands, including Hawaii. In Hawaii, it is classified as a native species, and is used in habitat restoration projects for degraded Hawaiian tropical dry forests, alongside the definitively native tree species Dodonaea viscosa and Cordia subcordata. It grows at elevations from sea level to 275 m (902 ft) in areas that receive 500–1,600 mm (20–63 in) of annual rainfall. It can grow in a wide range of soil types found in coastal environments, including soils derived from quartz (sand), limestone, and basalt, and it favors neutral soils with a pH of 6–7.4. The heartwood of the Portia tree is dark reddish brown to chocolate brown, with a specific gravity of 0.55 to 0.89. Portia tree is called milo or miro in Polynesian languages. It is popular in Hawaii for woodworking, and is commonly turned into bowls, due to its range of colors from tan through yellow to red. The trees were regarded as sacred in Polynesian culture, and were commonly planted in marae sites alongside trees such as Ficus, Fagraea berteroana, Casuarina equisetifolia, and Calophyllum inophyllum. It was traditionally planted in sacred groves and used for religious sculpture throughout eastern Polynesia. In Tahiti, Milo wood is used to make the to'ere, a slotted wooden drum used in traditional Tahitian tribal drumming. Makoʻi wood from this species was used for the rongorongo tablets of Easter Island. Since aluminum-hulled boats were introduced in the 20th century, people from Pitcairn Island have made regular trips to Henderson Island to harvest miro wood. They usually travel to Henderson only once per year, but may make up to three trips if the weather is favorable. Pitcairners carve miro wood into curios, which provides much of their income. In Hawaiʻi, ʻumeke (Hawaiian for "wooden bowl") has been a highly perfected art form, and ʻumeke have been considered prized possessions for well over a thousand years, especially those made of Milo and Kou, because these dense hardwoods do not add flavor to food. Before 1819, ʻumeke were considered sacred and strictly reserved for ʻAliʻi (Hawaiian royalty), and commoners faced the death penalty for possessing one. Today, ʻumeke are highly collectible and have become known as a universal symbol of generosity and welcome. In New Ireland, Portia wood is used to make hourglass drums. In Tonga, its bark is used to treat mouth infections in infants, and its wood is used to make canoes, house parts, and artwork. In Indonesia, this species is known as baru laut, baru pantai or waru lot, and people from Ambonese cook its leaves into a vegetable dish. In South Asia, its wood is used to make the thavil, a Carnatic musical instrument of South India. The flower of the Portia tree played a role in Sri Lanka's independence movement: it was sold on Remembrance Day by the Suriya-Mal Movement instead of the poppy, to support Sri Lankan ex-servicemen. Early Tamil people used the tree's wood to make instruments in ancient Tamilakam. It can be used for cellulose production from the plant (Singh et al. 2019). In some parts of the world, such as Hawaii and southern India, T. populnea is considered an important species for coastal dry forest habitat restoration projects.
