Flora:Driftree

Driftrees are unusual plants in that they spend most of their life floating high in the air. Their systems are remarkably adapted for life in the sky. The main body of a driftree consists of a woody bulb with ten to sixty wide leaves radiating from the top. These leaves hang over and form an umbrella to catch the air and help keep the driftree afloat. Of the two species of driftree, the Greater Driftree has the largest set of leaves, with a diameter of up to 210 ft (64 m). Above the base of the leaves are the main flight aid of the plants—large inflated sacs (which are actually specialized leaves) that produce methane. Another feature of the driftree is its long intertwining root system, which hangs down from beneath the plant like a jellyfish‘s tentacles. This root system can be over 300 ft (91.4 m) long, and forms a veritable habitat for various small creatures like the rootcrawler.

Life Cycle
The life cycle of the driftree goes as follows: After hatching from a seed, the driftree is still rooted (loosely) to the ground, feeding mostly on the food provided in its heavy seed. During the plant’s early stages of development, the methane sacs are the fastest part of the plant to grow; the diameter of the sacs may even stretch past that of the leaves at some point. Eventually, the plant becomes uprooted by its own weightlessness, and begins to float upwards. It continues to grow as it floats in the atmosphere at heights of up to .8 mi (1.3 km). At these heights, most of the driftrees’ water comes from condensation on the roots and leaves. Driftrees have a unique system of reproduction. Beneath the leaves are the gonads, which produce gametes. Throughout most of its life, the plant’s gonads are active producing spores. Upon reaching full maturity, these structures become swollen with sex cells, and begin to continuously release spores into the wind to fertilize other driftrees. The driftree has a feature which is unusual for most plants on Helen, as it has two distinct types of gametes: one is ciliated and small (sperm cell) and are the actual cells to be released into the air; the other type of cell is large and round (ovum), and stays the within the plant’s gonads to become fertilized. Other Helenoplantae only release some cells while leaving others to be fertilized, but the cells are the same in structure and appearance either way. The driftree is one of the few plants on Helen with dimorphic sex cells.

Once these two types of cells from different plants come together, each seed begins to grow inside the ovary, developing into a large, thick pod about the size of a baseball, and weighing up to 6 lb (2.7 kg). These seeds can weigh down the plant, but they soon drop to the ground in a matter of days, splitting open upon impact. Thus, the life cycle begins anew. After releasing all its gametes, the parent plant dies, and its methane sacs empty out slowly as it falls to the ground.