Forest restoration research in northern Thailand: 2. the fruits, seeds and seedlings of Gluta usitata (Wall.) Hou (Anacardiaceae)

Gluta usitata was one of the first tree species we looked into as a potential framework species for restoration lowland deciduous forest. Its red-winged fruits put on a spectacular display at the height of the dry season, near the Kruba Sri Vichai statue at the foot of Doi Suthep. But, be careful if you work with this species. Like many other members of the Anacardiaceae (e.g. mango and cashew) its sap can elicit a severe allergic reaction in those who are susceptible.

ABSTRACT: Gluta usitata (Wall.) Hou (Anacardiaceae) is a common, deciduous, native species, found mostly in deciduous dipterocarp-oak forest and bamboo deciduous forest 350-1,240 m above sea level. It is usually leafless from March until April. It flowers from December until March and fruits from January until May. Seeds begin germinating 16 to 23 days after sowing and continue to do so over about 2 months. Detailed descriptions of the fruit, seed and seedling are presented. G. usitata could be a useful tree for inclusion in replanting programs to restore deciduous forest below 1,000 m elevation. Seeds, collected in January-March, should be sown in forest soil or compost in individual plastic bags (6.5 cm x 23 cm), with slow-release fertilizer added. Seedlings, grown in full sunlight, should be ready for planting in about 18 months (i.e. at the beginning of the rainy season of the year following seed collection).