Philippine rosewood (En: trade name)
Common Name: Toog (Filipino), kapullan (Cebu, Visaya)
Scientific name: [Petersianthus quadrialatus (Merr.) Merr.]
A deciduous, medium-sized to fairly large tree that grows up to 40 m tall and 100 (-250) cm in diameter. The trunk is straight, cylindrical, branchless with a length of 20-30 m. Buttress is occasionally up to 2 m high. Bark surface is flaky, fissured, dark brown to grayish red; inner bark is tough, fibrous, and pinkish. Leaves are arranged spirally, simple, alternate. Flowers are in panicles, and have four white petals. Fruit has 4 seeds, in capsule, circular with four papery wings. Wood is hard and difficult to cut. Toog has been found to strong as akle, ipil and molave. Because of its appearance and high quality, toog is now recognized in the local and world market under the trade name Philippine rosewood. However, it is considered a vanishing timber.
Wood is manufactured into face veneer, pulp and paper making and fancy plywood. It is also suitable for general construction, beams, joists, paneling, bridge building, mine timber, pallets, poles, wood piles of wharves and piers and vehicle bodies. It is highly preferred for door faces and door components like jambs, stops and casing that are sold in major export markets, It branches, twigs, sawdust can be used in making charcoal briquettes.
Seeds are edible and taste like peanuts.
Leaves are medicinal especially in treating skin rashes.
Petersianthus comprises only two species. One occurs in tropical West Africa. The second species, P. quadrialatus (Merr.) Merr. (synonym: Combretodendron quadrialatum (Merr.) Knuth), is endemic to the Philippines. Toog abounds in Agusan, Surigao, Davao del Norte, Leyte, Samar, Negros and Masbate. It is also reported to be growing in Laguna, Sorsogon and Bataan.
Toog is fairly common and grows scattered in primary rainforests, near riverbanks or on hillside, in swampy and cool places.
Toog grows in an elevation that ranges from sea level up to about 400 m. It thrives in an area where rainfall is evenly distributed throughout the year. It requires well-drained, clayish, sandy and loamy soils.
Flowering of toog is erratic and apparently triggered by sudden fluctuations in temperature. It occurs between July and February. The fruit takes about one moth to mature, between March and May. Trees remain leafless during flowering and fruiting and buds appear after seedfall. Toog is a prolific seeder.
Toog is propagated through seeds. After 13 days in storage, the seeds have a viability of 60% and a survival rate of 52%. Toog seeds lose their viability very rapidly, hence, should be sown after collection.
Young plants must be ring weeded. A mortality of about 11% was recorded for nonweeded control plot.
Natural regeneration is very scarce. Seedlings can be found as far as 200 m from mother trees, especially between buttresses. Seedlings are established on bare soil, e.g., along roads. Toog trees coppice easily.
Early development in the nursery is rapid and height increment in the first 4 months averages 31 cm. Height increment in a 2-year-old plantation was 0.7 – 2.9 m and diameter increment is 0.6 – 3.8 cm.
For ring-weeded plants, the mean diameter growth after two years is 2.99 cm.
Florido, Helen and Fe Cortiguerra. Research Information Series on Ecosystems. Volume 16 No. 1. January – April 2004. Ecosystems Research and Development Bureau. College, Laguna.