Stackstalk

While stackstalks seem to be a single flora, it is actually a colony composed of specialized clones called phytids. Each phytid can produce all other kinds. In the stackstalk, this is taken to the extreme, as each clone in a single colony grows directly atop a previous one and functions as a single flora. Typically, a colony starts from the underground stolons of a preexisting colony. A storage phytid (3) is created, which then clones itself to produce a synthetic phytid (2). The stackstalk colony then photosynthesizes for a while, collecting energy in its expanding storage phytid. The next summer, it grows a defense phytid (1), with a spore phytid (4) on top. The defense phytids are located close to the spore chamber, allowing them to puff an irritating dust directly into the nostrils of any herbivore that tries to eat the tender spore phytid.

The irritating dust consists of sharp-edged protein particles that are a modified version of ancestral spores. The defense phytids contain enzymes sensitive to carbon dioxide concentrations. When fauna breathe on it, a reaction occurs with the enzyme and growth hormones, causing the stackstalk to increase production of irritating dust. It cannot discriminate between fauna that plan on eating it and fauna that don't. It is useful only because fauna most likely to get close enough to a stackstalk to breathe on it are fauna interested in eating the stackstalk. The increased production of irritating dust does not immediately come into effect. Rather, the first breath of a fauna works as a warning of herbivory in the near future.

The defense phytids and spore phytids die off before winter. The photosynthetic phytid becomes inactive. The photosynthetic phytid has a ground-hugging shape, as Arctic plants do. This shape keeps it warm, as temperatures on sunny days are warmer near the soil surface. This is due to the soil, which absorbs sunlight and radiates heat. In the Arctic, the temperature near the soil surface can be 5 °C to 10 °C warmer than a few centimeters above it, but the Fermi Polar Beach's black sand means it's even warmer.

Synthetic phytids and defense phytid stems are covered in fine hairs that protect it from UV light overexposure during the long summers of its habitat. These hairs give it a hummingbird-like greenish iridescence.