Bramblevines

One of the many different seeds brought from the old continent was a fast growing form of invasive creeper known as the bramblevine. By seeding long strands of it out and using phytomancy to enhance its growth, thick barriers of difficult to cut through greenery can be formed. They can be stretched out at roughly leg height as a form of barbed wire, or they can be condensed to form tall walls that are nearly impossible to scale without burning or cleaving whole sections apart.

Initially, these were deployed in a similar fashion as they had in the old Growth. Small patches of area denial in order to focus a potential attacker down certain lines of progress, where ambushes and devastating traps can be deployed to shatter formations in the dense growth of trees that the Florans occupy. The enhancement of their phytomagical prowess by Austras leaves has opened new avenues of exploration. Whole outposts can be quick-grown, with walls that dissuade climbing animals and assaulting armies alike. The vines can also burrow underground, rooting the plants even deeper into the soil to minimize the effectiveness of sapping.

Though hearty, bramblevines are living things after all. They are fortifications that require both sunlight and a water supply, leaving them less useful on campaign in areas without adequate amounts of either. They can also be poisoned, and aren't terribly resistant to fire. Progress is ongoing to a flame-resistant coating that can be sprayed or Gene Twisted into the seeds themselves, but until then, the formidable walls retain an Achilles heel.

Rosalind, upon realizing that there are in fact other powers on the continent, went into full paranoia mode. She commissioned large scare bramblevine outposts, walls, and areas of denial to protect the frontier around New Zigdrasil. Limiting the movement of troops in their forest keeps the amount of territory their defenders have to cover. In the Growth's forest, every area can become a choke point, or a stronghold, or even an ambush. Tread carefully.