Kwila is the most well-known hardwood decking timber in use in New Zealand. It is a pale brown to dark reddish-brown coloured hardwood that comes in a nice length spread and is quite stable.
Its only downside it water-soluble tannins that leech from the timber with exposure to water, a process called bleeding. This resin will stain, so be careful with tiles and concrete work.
All Kwila is sourced as being VLC (Verified Legal Compliance) which is on stage 2 towards being FSC certified.