The golden trumpet-tree
Right now, at the onset of the hot dry season, also called the flowering season, you will find lovely indigenous flowering trees along the Chiang Mai mountain roads: snowy ’mountain orchid tree’ (Bauhinia variegata), red Erythrina spp, ’red kapok’ (Bombax ceiba), pink clouds of ’pride of Lanna’ (Congea tomentosa), ‘pink shower trees’ (Cassia bakeriana), orange Butea monosperma, orange Radermachera ignea and soon the white blossom of ’duabanga’ (Duabanga grandiflora). If you wish to learn more about native northern Thai trees you need Simon and Pindar Gardner’s book of which we have four specimens left.
In Chiang Mai town there are two exotic golden boulevard trees currently in blossom: the silver trumpet-tree (Tabebuia aurea, Bignoniaceae) with silvery leaflets on long stalks, and the golden trumpet-tree (Tabebuia chrysotricha syn. Handroanthus chrysotrichus) with golden flowers on virtually naked branches this time of the year.
Tabebuia chrysotricha. ‘Chrysotricha’ or ‘golden hair’ refers to the golden-brownish hairs on calyx and fruits (a dry capsule).
The genus Tabebuia encompass 60-100 species depending on how you define the genus and the species. There are many yellow species so an identification can be difficult. The scientific name Tabebuia is derived from a name used by Brazilian natives. Smitinand (2001) does not list any of these exotic species but it seems many yellow tabebuias are collectively called ‘lueang India’ in Central Thai language.
Some researchers use the stricter genus name Handroanthus, created in honour of the Brazilian botanist Oswaldo Handro (1908-1986). The golden trumpet-tree is supposedly the national flower of Brazil although not in a rigid sense (may be other Handroanthus spp). It is not only a cherished ornamental, but has one of the hardest timbers on the continent and is also used medicinally.
The ‘silver trumpet-tree’ can be seen on the Hang Dong-Chiang Mai road (108) and the ‘golden trumpet-tree’ grows along the Samoeng road (1269) and en masse along the freeway south of Chiang Rai. Evidently these species like full sun and a seasonally wet and dry monsoon climate. Some literature refer to them as rain forest (ever wet) plants, but I think in such cases the authors have a dim perception of what a rain forest is, and so it is much better to look up their geographical origin. If a plant comes from equatorial evergreen lowlands it is likely to be a true rainforest plant (such as mangosteen and durian), demanding a moist climate. If they come from deciduous tropical lowland forests they are likely to demand or survive a long and hot dry season. In this case T. chrysotricha is native to the Brazilian tropical dry Atlantic forests and T. aurea is native to the subtropical drylands of Gran Chaco in southern Brazil, Paraguay and northern Argentina.
This picture of the golden trumpet-tree is from Dokmai Garden. For best blossom, sacrifice the lawn!
Text & Photo: Eric Danell