Scientific name: Handroanthus serratifolius (Vahl) G. Nicholson (Syn: Tabebuia serratifolius)
Vern: iron wood, tabebuia (En); groenhart (Du); Ipe amarelo, pau d’arco (BPo); araguaney (Sp)
Local: groenhart (Sr); hakia, ironwood (GU)
Indig: arani (Tr)
Growth Form: Trees & shrubs
Order: Lamiales
Family: Bignoniaceae
Notes:
Handroanthus serratifolius (formerly Tabebuia serratifolia), family Bignoniaceae, is a colossal canopy giant native to primary tropical forests across the Guiana Shield and Amazon basin. Regionally, it is universally recognized by names that highlight either its dazzling, synchronized seasonal flowering display or its nearly indestructible wood. In Suriname and French Guiana, it is known as Groenhart (Greenheart) or Grienhart, in Guyana as Hakia or Ironwood, in Brazil as Ipê Amarelo or Pau d’arco, and in Venezuela and Colombia as Araguaney or Guayacán.
The species is a legendary heavy hardwood, producing timber so dense and heavily saturated with natural lapachol compounds that it sinks in water and possesses a natural fire resistance equivalent to concrete. This exceptional durability makes it highly resistant to rot, marine borers, and termites, turning it into a premier commercial choice for heavy-duty marine construction, railway sleepers, and high-end outdoor decking (marketed globally under the trade name Ipê). However, this extreme density makes it notoriously difficult to mill, causing rapid dulling of steel cutting tools in local mills.
Ecologically and culturally, the tree is famous for its brief, explosive strategy of synchronized mass flowering. At the height of the dry season, the entire tree drops its foliage and bursts into a vibrant, brilliant cloud of golden-yellow, trumpet-shaped blossoms. This short, intense blooming window draws in a massive influx of native canopy bees and nectar-feeding birds, while acting as a vital phenological marker for indigenous communities, signalling seasonal shifts and seed-collection timelines across the interior forests.