Sonneratiaceae
Crabapple Mangrove
Source: James A. Duke. 1983. Handbook of Energy Crops. unpublished.The heavy wood (800 kg/m3) is used for boatbuilding, construction, piles, and posts. Sour young fruits, used in or for vinegar, are widely used in Oriental chutnies and curries. Ripe fruits, said to taste like cheese, are eaten raw or cooked. A clear jelly can be prepared from the pectinaceous fruits. Pneumatophores cut up and used as corks or floats for fishing nets. The pulp is suitable for kraft paper production. Flowers, in anthesis, contain abundant honey (Backer and van Steenis, 1951).
Reported to be hemostat, crabapple mangrove is a folk remedy for sprains, swellings, and worms (Duke and Wain, 1981). Burmese use the fruits for poultices, Indochinese poultice crushed leaves with salt onto cuts and bruises. Malayans use old fruit walls for worms, half-ripe fruits for coughs, and pounded leaves for hematuria and smallpox (Perry, 1980).
Fruits yield 11% pectin (ZMB). Wood yields 52.7% brown pulp (8.5% lignin, 17.6% pentosan). Emodin and chrysophanic acid may be the coloring matter in the crude drug (Perry, 1980). Bark from Africa assayed at 17.1% tannin, of the pyrogallol class. Indian stem bark assayed 9–17%, twig bark 11-12%. Wood yields two coloring principles, archin (C15H10O5) and archinin (C15H14O12 ) (C.S.I.R., 1948–1976).
Evergreen tree 5–15(–20) m high without buttresses or stilt roots, with rather open spreading crown, glabrous throughout. Pneumatophores 50–90 cm high, to 7 cm in diameter. Bark gray, coarsely flaky. Leaves opposite, without stipules, nearly sessile, elliptical, oblong or ovate, 5–13 cm long, 2–5 cm wide, with broad or tapering base and blunt or rounded tip, entire, with 8–12 widely spreading fine side veins on each side, leathery. Flowers 1–3 at end of drooping twigs malodorous, nocturnal. Hypanthium with 6–8 calyx lobes; petals 6–8, 2–3.5 cm long, 1.5–3.5 mm wide, dark or blood-red, stamens numerous, with threadlike filaments 2.5–3.5 cm long, pistil with 16–21-celled ovary with many ovules; style long, stout (Little, 1983).
Reported from the Australia, Indonesia-Indochina, and Hindustani Centers of Diversity, crabapple mangrove, or cvs thereof, is reported to tolerate coral, disease, insects pests, salt, and waterlogging (NAS, 1980; Little, 1983). (2n = 24 in other Sonneratia).
Sri Lanka to Malay Peninsula and northern Australia. Also Sumatra, Java, Borneo, Celebes, Philippines, Moluccas, Timor, New Guinea, Solomon Islands, New Hebrides. Not widely introduced (Little, 1983).
Estimated to range from Tropical Moist to Rain through Subtropical Moist to Rain Forest Life Zones, crabapple mangrove is estimated to tolerate annual precipitation of 10 to 80 dm, annual temperature of 20 to 27°C, and pH of 6.0 to 6.5. Usually on the less salty parts of mangrove forests on a deep muddy soil, never on coral banks, often along tidal creeks with slow moving water, ascending these as far as the flood mounts (Backer and van Steenis, 1951).
According to the NAS (1980), planting is usually not needed because natural regeneration is so successful. In Avicennia and Rhizophora, direct seeding results in ca 90% survival.
Harvested as needed from wild stand. Trees recover rapidly after branches are lopped off for fuel. Since this mangrove can regrow rapidly from buds beneath the bark along the trunk and branches, it is said to suffer little from removal of much of the branchwood (NAS, 1980).
Cannell (1982) cites data on a mangrove forest dominated by Rhizophora, Ceriops, and Sonneratia, averaging 11 m tall, with an LAI (leaf area Index) of 3.7–4.2.The stemwood and bark on a DM basis weighed 74.4 MT/ha, the prop roots 61.2 MT/ha, the branches 15.8, the foliage 7.4, the fruits 0.3, for a total standing aerial biomass of 157 MT/ha. The CAI (current annual increment) of stem wood, bark, and branches was 20 MT/ha/yr, foliage 6.7, fruits 0.3. These data, taken from a mangrove on Phuket Island, Thailand, regenerated following clear felling, suggest annual productivity may attain 20 MT/ha/yr in Asian mangroves.
Although the calorific value of the wood is above average, it is inferior to true mangrove, and has a high ash and salt content.
Heartwood is said to be very resistant to teredos.