Apterra's tropical pseudoforests are no longer the lush, paradisaical havens they once were. While in the past this was among the most widespread terrestrial biomes on the planet, it now exists only in a handful of localities scattered around the equator. The Remnant Rain-Pseudoforest is the new name for what was once Loxodia's mighty jungle, a habitat that used to support one of the most diverse communities of plants and animals anywhere on the planet. More than half its endemic species have already vanished, and the ecosystem harbors an additional extinction debt of dozens of vertebrates and over a hundred plants over the next ten thousand years or so, by which point the temperate zones will have crept even further into what was once tropical territory. As the end of the tropics looms closer, the species that have survived this far are being pushed to evolve in new directions. Those that can sustain themselves on few resources, like the sweetstalks, have held out, while plants that recently arrived in the region from colder climates are escaping the rain-pseudoforest altogether, leaving behind those that can't withstand freezing temperatures. More successful holdouts like chainanas and non-tree mycads make up the bulk of the survivors, soaking up every drop of sunlight and preventing smaller plants from growing below. Any species that hopes to continue living here, therefore, is forced to climb higher and higher, stretching high into the canopy in search of energy.
Shadeblades arrived in what would become the Remnant about a million years ago, back when success was all but guaranteed for any plant that expanded into one of the pseudoforest's many empty niches. They grew as long, trailing vines, climbing the abundant palm-grasses and other pseudotrees. They rarely caused major damage to their host plants, as their lifespans were too short to reach sizes large enough to choke out the grasses that supported them. Arboreal woodlouse colonies usually left them alone, as their tough leaves did not attract many herbivores. When it came time for them to reproduce, they would grow a few hundred small grains that dropped to the ground below, after which the parent plant would die. In those days, more light reached the pseudoforest floor, and it was not very difficult for seedlings to creep their way towards a pseudotree trunk.
As the years marched on, these tropical shadeblades established themselves as a minor player in this massive jungle. Generations came and went, silently and unknowingly witnessing their home shrink a tiny bit every year. Cold snaps pushed back the rain-pseudoforest along its north and south edges, and one by one the plants that shared the shadeblades' range disappeared. A few tall species remained, and the sprouts saw the sky above them darken as the overstory grew denser. They became more tolerant of these conditions as the light faded, growing bigger grains to give their progeny a better chance of finding a pseudotree by the time their stored calories ran out. Even so, the vast majority failed, granting a significant advantage to those individuals that produced a larger crop of seeds. This required a huge investment of nutrients, more than their small, inconspicuous ancestors could muster.
In response, shadeblades grew larger, bushier, and more aggressive, converging on the parasitic lifestyle of their cousin the strangler bladevine. Unlike both that genus and the original shadeblades, though, this new species no longer died after blooming, persisting for many years until its host rotted and collapsed underneath it. By this time, the Remnant Shadeblade had diverged enough to be considered its own species, Umbrolamina reliquus. Mature individuals can entirely cover a pseudotree, stealing every bit of sunlight that would've otherwise reached it. Unchecked, it can kill in a matter of months, but rarely does it grow without setbacks.
Arboreal woodlice now fight its foliage, cutting off any tendrils they spot growing on or near their particular palm-grass. On occasion, though, one slips past their watchful mandibles, entangling itself within the foliage of plants like mycads. Before long, the isopods will likely discover and destroy its main stem, severing its connection to the soil below. While this would kill any other bladevine, the remnant shadeblade can recover from such damage with ease. Its adventitious roots, used by other Acutipampinaceous plants to anchor themselves to surfaces, have adapted to pierce the exposed tissue of the palm-grass, leeching xylem and phloem from within its trunk. Once anchored into an unfortunate pseudotree, this trait allows them to fully detach themselves from the ground, continuing to grow despite the pill bugs' best efforts. In some cases, the woodlice can still prune away the vines, as the interlopers cannot regrow from just their embedded roots, but their window of opportunity is brief; after just a few weeks, the ailing mycad will have lost so much energy that it can no longer secrete enough nectar to feed its protectors. At this point, the isopods either die off or disperse to other woodlouse-grasses, leaving their former home undefended and doomed to a drawn-out death by shadeblade. In many cases, Plague isopods notice the dying plant and put it out of its misery. With food becoming scarcer, the folivorous woodlice can no longer afford to be picky with their diet, and they are becoming increasingly willing to eat the vine in addition to its host.
Chainanas are another common target of these vines. Lacking crustacean symbiotes, they resort to other defense strategies. Luckily, their fast-growing blades are quite resilient on their own, emerging from the center of the plant and unfurling in a matter of hours. Lower, older leaves may be overtaken by the shadeblade, but as long as the chainana continues pushing new ones out on top, it can usually stay ahead of the parasite. In the worst-case scenario, it can also grow new shoots from its base, quickly replacing any stalks that succumb to the sap-draining roots.