Endemic Flora of the Gecko Isles

As was the case 80,000 years ago, the islands dotting the sea north of Abeli are home to an environment quite alien to its mainland counterparts. There are no rats here, leading to an abundance of kiwis and geckos. Indeed, this assortment of islands contains the sum total of all Correlophus individuals on the planet. Two dozen or so species have radiated from their progenitors who rafted here all those millennia ago. Here, small burrow-dwellers cower from the predatory kiwis that stalk the plains, while more gracile forms climb cautiously through the Bouteloua overhead, on the hunt for nutritious grass seeds before they get a chance to fall and germinate. Nearly quintuple their size, an isopod-eater turns over rotting leaves and debris, chomping down on a few stragglers as its prey scurry away into the underbrush. A mottled gray lizard, the smallest of them all, leaps into the air from its perch on a blade of grass. Tumbling back to the ground, it contentedly gulps down the mosquito it's just caught. All these geckos and more owe their existence to this island refuge. They are not, however, the only organisms who call this place home.

Just after the divergence of the basket-grasses at the end of the Dawn Muricene, a few wayward seeds belonging to that lineage made their way here. While on the mainland these forms make up roughly 10% of plant biodiversity, they are the dominant clade of grasses in many of the islands' ecosystems. In all, more than 50 species of basket-grasses dot the archipelago. They are most successful on the open plains, where their fast growth is unmatched by their congenerics. Here, a subgroup of the basket-grasses has emerged. These are the barrel-grasses, characterized by the presence of a long, horizontal petiole that distances each blade from the central rosette. The basal barrel-grass is roughly half a meter in height, with vertical blades forming a dense ring around the middle of the plant. Newer leaves grow successively further out over time; if the plant lives for many years, there can even be a small dead zone in its center where other plants may sprout.

In its more specialized forms, the barrel-grass can become a true behemoth. Bouteloua giganteus is a species found across the prairies of the gecko isles. It is fundamentally quite similar to its relatives, but at a much greater scale. When mature, its stiff, pointed blades can reach four meters in height, and the diameter of the "barrel" is of similar size. The ring of blades is roughly a meter thick and packed with foliage. Within these walls, however, is an oasis of biodiversity. In this area, the giant barrel-grass has already consumed all the minerals and nutrients it needs, leaving behind a soil quite inhospitable to others of its species. However, other buffalograss-descendants with different nutritional requirements find this microhabitat very friendly. Shorter turfgrasses grow here, as do soft annuals that would find themselves quickly destroyed by the local herbivores if they'd sprouted anywhere else. These build up a layer of organic matter that completely covers the petioles and meristem of the barrel-grass. When the day comes that the barrel-grass finally dies, another mini-ecosystem is created. All the old inhabitants of the dead zone quickly meet the same fate as their host. Small, fast-growing barrel-grasses crop up within weeks, colonizing the corpse of their larger cousin before any other plant has a chance to sprout here. By year's end, they'll have set seed, their grains scattering in the wind in hopes that one or two will land on another dying giant. The next growing season will see the proliferation of slower-growing forms that are well-adapted to survive in this patch of now nutrient-poor soil left behind by the annual barrel-grasses. These persist for up to half a decade, the earth beneath their roots slowly regenerating into a more fertile state. Only now can another generation of giant barrel-grass seeds sprout. They'll grow continuously for many years; after their first three or four seasons, they'll be big enough to harbor internal communities once again.

In the highlands, these tall grasslands give way to a dense pseudoforest. Unlike on the mainland, though, the "trees" here are not palm-grasses. Rather, the overstory is composed of the descendants of early tall grasses of the Dawn Muricene tropics. The Bouteloua planifolia subgenus are among the progeny of those early jungle-grasses. In their former range, they've long since been replaced by the hardier woodlouse symbiotes. Here, though, there is little need for this mutualism; regular dry spells ensure mold outbreaks are rare. They've seen widespread success here, as they are the tallest stalked grasses of the isles. The tips of their blades are, on average, about three meters high, with exceptional individuals sometimes reaching double that size. Their stems are relatively normal-looking, remaining unchanged from their ancestral state in all aspects except scale. At their ends, however, lies this group's signature adaptation: the leaves grow in a wide frond emerging from the tips of each limb, radiating outwards in a semicircular arc. 

From a photosynthetic perspective, this is quite an efficient arrangement, as blades tend not to overlap one another. It does mean, however, that a decent amount of light escapes between the fronds, filtering down to provide nourishment to the understory grasses below. One of the most numerous of these are the paddle-grasses. Like the basket-grasses, their stems have been compressed to the point that they do not emerge above the ground at all. They distinguish themselves from other groups of Bouteloua in the pattern of their leaves. Their foliage grows in planar "paddles" of blades fanning out from the central meristem. These leaves have tube-like petioles, with newer ones growing inside older ones. To reach the outside world, each new petiole must grow a centimeter or two taller than the previous. The resulting paddle is, therefore, strengthened by many layers of this tough, fibrous "stalk", which also serves to store precious water during dry periods.

Conserving moisture becomes increasingly vital as one continues ascending the slopes of the largest islands. Here, rain may not fall for up to a month at a time - a far cry from the true desolation of the Loxodian deserts, but more than sufficient to facilitate another change in the dominant local grasses. Here, dwarf paddle-grasses cling to the sandy soil, reducing erosion during storms and therefore creating a livable habitat for other plants. Basket-grasses grow here, their leaves shortened to reduce surface area and ending in sharp, thorny tips. These are not of the barrel-grass group, but descend from the same common ancestor that arrived on the gecko isles many years ago. Nondescript scraggly turfgrasses also populate these mountains, digging their shallow roots into the paddle-grass-stabilized earth. The largest plants here, though, are members of the species B. hydrosorptor, a species that has only recently diverged from these basal forms. It remains quite conservative in its structure, looking relatively normal compared to many of the other species that inhabit its range. The only thing unique about this species is its stems. When the rains fall, they swell to over a dozen centimeters in width, every cell inflating to massive proportions as they take in every drop they can get. This water will sustain them through even the worst drought, allowing them to grow and thrive while other grasses have no choice but to enter a state of dormancy to avoid complete desiccation.

The last major biome of the gecko isles exists along its coastline. Winds buffet the shore, uprooting any plant whose roots don't sufficiently anchor it into the loose sand. The windswept paddle-grass, B. anemofortis, is one of the few that can bear the strongest of these gales. It grows along the rolling dunes just a few meters from the waves. Their paddles are thinner than those of their highland cousins and always grow perpendicular to the beach, presenting little surface area for the wind to act upon. Certain basket-grasses take advantage of their fast growth by simply allowing their blades to break away in high winds, allowing the plant to regrow over the next few days. One, however, has a different strategy. Its leaves are in the shape of long, flat triangles, lying at the tips of elevated petioles. When the wind blows, it pins the plant to the ground, flattening it against the sand until calmer weather arrives. In a matter of hours, the leaves recover and stand up again, ready to continue about their business photosynthesizing and producing the next generation of pennant-grasses.

Many of these lineages will someday reach the mainland; at this stage in Apterra's development, there are still many unclaimed niches for them to fill. Others will never find a home anywhere but here. More migrants will arrive with time, and new innovations within existing groups will shake ecosystems to their core. The insular environment created by the species described here, however, is the foundation upon which all future forms will build.