Protrilaphyta

Protrilaphyta is a class of leafless vascular Atarian plants. A member of this class is known as a protoid. They are medium to very tall, fast-growing shrubs and trees that are found in most environments on Atar, but dominate in places too cold or dry for leaf-bearing trees to grow. Instead of leaves, the entire above-ground surface of a protoid is able to photosynthesize. The wood is relatively soft; their support is aided by a "frame" made from lignified tissues hardened by natural polymers, including protulene. The frame ranges in form from a solid core to an intricate lattice-work, and from rigid to very flexible, depending on species and growth environment. Species in the family Sinesaceae lack an internal frame.

Protoids are the direct descendants of some of the first plants to colonize Atar's land surface; they appear in Atar's fossil record in rocks dated to around 680 million years old, at a time when the land surface was otherwise devoid of vegetation. The type genus, as well as the largest in terms of number of species, is Protus, in the family Protaceae. Around 10,000 extant species are known, and over 500 extinct species have been described.

Certain species of protoid in the protus family Protaceae produce large frames rich in protulene that are used in a wide variety of uses, such as materials for ships and other vehicle bodies, with the resulting byproduct, chloromatter, used as a nutritious food for the incarcerated or famined, albeit with a universally objectionable taste.