Wormwort

Although southern wormoss made significant strides inland (or crawls, anyway), they had not broken the tie to water to reproduce... until now.

Wormwort solved this challenge by, in effect, having its juveniles serve as its own pollinators. As before, the juveniles produce sperm starting quite early in their lives, but they now keep it inside their bodies instead of spawning. On encountering an adult, they brush against the joints between the segments at its base, where they pick up a dusting of eggs, which they breathe in through their spiracles. The juveniles then fertilize these eggs inside their body and gradually secrete fertilized eggs as they travel along, mixed in with the mucus that they exude through gaps between their segments. These gametes all consist of two cells, one each for the soft core and the outer shell. The adults no longer produce sperm, as the juveniles had no incentive to transport other individuals' sperm. As a result, the terms "adult" and "juvenile" are no longer really the best descriptors; we can instead speak of a mobile young male form and an immobile mature female form.

Indeed, the mobile young now comprise a much longer part of their life cycle; they may spend a couple of years in this phase. They are similar in form to before, with a segmented chitinous outer shell, which has spiracles in the gaps between segments, and they secrete mucus both to keep the inner core moist and to provide a lubricated surface to crawl on. They require a lot of water as a result and are therefore most commonly found near the shore or near rivers, streams, and ponds. But they range further inland during rainfall or when seeking reproduction or when ready to plant themselves. Inland puddleface also provides an additional source of water to drink. With a longer and more active lifestyle, the young have a slightly more complex nervous system, with a ganglion in each segment, though they're still limited to simple preprogrammed behaviors. Their eyes are simple pigment cups between each segment. They eat through an opening in the shell on the underside of the head, where a muscular fleshy portion of the inner core is able to protrude outward, grip food, and rub it against the shell opening, which is enough to suck in or even tear off bits of soft food. They mostly subsist on decaying matter, including dead of their own species, but soft flora like violetweed is edible too. The outer shell also photosynthesizes, which supplements their energy and keeps them going through lean times but is not enough to sustain consistent movement.

After reaching about a centimeter in length, they'll find a spot to plant themselves. Stability was always difficult for the ancestral wormoss. In wormwort, the leaf-thorns at the base now turn to the side and downward, hooking the mature wormwort into the ground to make it harder to be blown or knocked over. As with southern wormoss, they have relatively small segments, but they grow more of them over the course of several years and typically reach about four centimeters in height. The mature form reabsorbs the young nervous system and eyes into the body, though the spiracles remain for gas exchange. The mouth grows an extended funnel shape for collecting rainwater. The digestive tract splits into multiple vessels for conveying nutrients and water throughout the organism.