Trident Cushio
The Trident Cushio is descended from riparian populations of the Cushion Bush. It was able to grow so much larger than its ancestor, so suddenly, due to the lack of competition for its size range in its temperate riparian habitats: there was only the Giant Kraltree (18 meters tall, 24 meters wide), Darwinian Shadow Fortress (48 meters wide, 24 meters tall), and the bush-like 30-50 centimeters tall Shrub Gazebos. Trident Cushios grow faster than crystal trees, although they have shorter lives. In controlled, ideal conditions, it grows three main branches, which split into fork (or trident-)-like arrangements, hence the name. However, in the wild, damage from wind or herbivores can cause it to deviate from this plan.
Superficially, its trunk and branches seem to be made of wood. However, it is soft and spongy: much like the wood of an ombu tree of Earth, it is a mere secondary thickening, rather than true wood. Indeed, its “wood” is so soft and spongy it can be easily cut with a knife. In wild conditions, it’s almost inevitable it has a few small, scar-like cuts due to its soft tissue. While its “wood” is very soft, on a per-unit basis it’s the hardest of its contemporary relatives. Its sap is a ruddy purplish color, and fresh injuries look pinkish-purple before healing to dull purplish-greyish. Beneath its outer, bark-like tissues, the taproot is a reddish taupe color.
Its long, thick taproot is somewhat woody, like an over-mature carrot. If it grows for long enough, the tip of the taproot develops fork-like extensions, much like its branches. Strangely enough, the taproot of mature specimens is actually harder than its trunk.
Something like a birch, a Trident Cushio is a pretty fast-growing “tree” adapted to the taiga. As the fastest-growing of its contemporary relatives, it grows about 0.30 m (1 foot) a year, taking roughly 6.8 years to reach full size.
Trident Cushios have the biggest leaf size of its relatives, and it’s suited for wetter, milder conditions in its habitat. As its branches are stiffer than its relatives’, they are prone to breaking off in strong winds.
Environmental Adaptations
Its roots (and by extension, the organism itself) grow best in sandy soils. Trident Cushios can germinate in high-clay soils, but die long before reaching adulthood, and rocky soils are completely uninhabitable. Its outward-sprawling roots make it best at capturing rainwater among its relatives, which is handy, given sandy soil drains quickly. Its extensive system of shallower roots and root hairs (not visible at this resolution), are connected to nodules that host nitrogen cycle microbes, chiefly globanitrates. Its nitrogen-harvesting nodules go only 40% of its total taproot length, if that.
Its taproot helps it anchor itself during the rare catastrophic floods of its habitats, as well as access water (of less utility now, since it lives so close to a river). It also stores energy in the root, which helps it regenerate from weather or predator damage. This is more of an issue while it is still small, given its especially low defenses at that time.
Ecological Interactions
Although it spread to Darwin Temperate Woodland afterward, the many trees already there successfully compete against it, making its distribution patchier and limited to low-nitrogen areas, sandier areas, and lowlands. It can grow on the sunnier end of part shade, which helps it survive near much bigger trees. However, its growth is stunted compared to full sunlight conditions.
In the scale of secondary succession of a habitat, these dominate the riparian landscape in stages 5–6, but are pushed to the margins as huge crystalflora trees mature. They thrive when roaming bands of herbivorous tauroks (Forest Centaurok, Gigantaurok) strip branches of crystalflora trees’ crystal-leaves, giving them more sunlight.
As it lacks true wood, the entire plant is digestible to any herbivore equipped to deal with somewhat difficult-to-digest foods. The sprouts especially are pretty tasty and digestible, like sunflower sprouts. Its low defenses and relatively slow growth rate would be more of a problem if it had more predators.
Reproduction
Trident Cushios are hermaphrodites: they grow male and female reproductive structures from separate “flowers”. The thin, hairlike reproduction structures grow from the tips of their branches. The structures, called "ketkins", are somewhat similar to birch catkins, except long, thin, and dark purple. The male ketkins detach in the wind, and if the wind-borne hairs settle on the female ketkins of another Trident Cushio, they are able to fertilize the gametes. The female ketkins then develop small, lightweight “seeds”, which are actually short, thin ribbons of embryonic tissue, with no food supplies. The female ketkin dries up, releasing the seed-ribbons in strong winds. The seed-ribbons undulate as they are carried by the wind, bringing to mind a flying snake's "flight" (although the Cushio's "flight" is passive).
Male flowers’ curling shapes makes it easier for them to be caught on the branches of others of their kind.