The Deltalands of central Ailuropia are a vast patchwork landscape of prairies, gallery forests, deserts, and open savannas. The massive continental glaciers of the Ice Age pushed enormous hills of rock and debris up on the western edge of the basin, eliminating the valley's only outlet for rainwater. Now, massive rivers flow from the landward slopes of the two mountain ranges, coursing through the lowlands until they reach one of many natural depressions. At certain times of year, the deltas are flush with life, as the water spreads out and disperses its sediments and nutrients across a wide area. But as mighty as these rivers are, none of them reaches into the very center of the continent. The heart of the Deltalands is characterized by a hilly savanna that receives just barely enough rainfall to support a thin scattering of trees. This is perhaps the last place one would expect to see a shadeblade, which for millions of years were specialized to live in dense pseudoforests, reaching toward rare pockets of sunlight while they sapped the energy of their host tree. But a lot has changed since those days, and one species has taken advantage of a new opportunity.
The Creeping Shadeblade (Retevinus ponticulus) is one of the remnant shadeblade's many descendants. Its life begins just like its ancestor - as a large, hard seed sprouting in the earth. A long tendril begins snaking its way across the ground, stopping only when it reaches a palm-grass tree. Its roots puncture the plant's flesh, leeching water, minerals, and nitrogen from its tissue. If it's lucky, it grows faster than it can be pruned away by various Scansoriarthriform isopods, and it overtakes the tree completely in just a few months. Yet its growth is far from complete.
The shadeblade begins spreading once again across the savanna, sending out a dozen or more thick tendrils. Fueled by the abundant energy of the central plant, these may grow up to a meter a day. Each vine has a hard outer layer of bark-like cells that protect it from herbivores as it lays exposed on the ground. Inside, there is a much softer fleshy core. The cells of the interior are pumped full of water, accelerating the vine's growth. After crossing up to fifty meters of open landscape, the shadeblade finally reaches its next target. Its roots once again work their way into the palm-grass's insides, weakening its defenses as it climbs higher. Once the parasite has established itself, another change occurs.
The tough bark covering begins to flake off the vine. The inflated vacuoles of the connecting segment shrivel, rerouting their water to the newly-rooted offshoot. This causes the vine to shrink, pulling itself taut and lifting up from the ground. Its strongest roots anchor it to the upper trunk of each tree, while weaker roots closer to ground level break away easily. Soon, the vine is suspended in the air between the two trees, forming a bridge up to thirty meters long and fifteen meters above the surface of the savanna. This allows the two portions of the plant to communicate, keep out of reach of threats, send nutrients back and forth, and remain a single cohesive organism, even as the plant grows across vast areas. After many years, the web of shadeblades can stretch across a hundred hectares or more. The bigger it gets, the less it needs to steal from each individual tree within its span, so mature individuals live in balance with the local palm-grasses.
The oldest vines may gradually regain their hard covering as layers of cells slowly die from the outside in, though the soft core continues to persist for up to twenty-five years. Sooner or later, a few key connecting vines will wither or be severed, forcing the fragmented ramets to compete with one another. This is the most common cause of mortality in this species, as it provides opportunities for arboreal isopods to clear away the weakened shadeblades before one can emerge as the winner. The palm-grasses then get a chance to grow uninhibited, providing a suitable home for the next generation of vines a few months or years down the road.