'You're in the jungle, baby!'
Pretty much everything you've been travelling through since the Wickshine's Last Inn is BIG trees, lots of undergrowth (you're well off the beaten path), grueling mountainous terrain, and humidity so high it almost feels like Skáth's swimming instead of flying. The growth is mostly tropical evergreen, with a smattering of tropical deciduous. It rains at least an hour or two every afternoon (this is the dry season) and it's HOT. Though the party passes through 'clearings' several times a day, they are not what most would consider actually clear - they're usually made when a large tree falls, taking down a few smaller trees and lots of undergrowth on the way down. Due to the rapid growth rate 'round here, unless the clearing is recently made visibility will be somewhat better (not as many trees) but travel will be just as difficult - the undergrowth has moved right back in. In some cases, getting over or around the fallen tree is harder (for everyone but Skáth) than 'normal' travel.
However, it should be said that this terrain is 'normal' for any party member raised in the highlands (right at half the party, I think).