The Rain Thistle is one of a family of plants that grow across the Western Frontier of Pandora, closely related to the Fog Bloom and the Sailfin Blossom. Although they share numerous traits, they are readily distinguishable from each other, each plant uniquely adapted to its preferred climate.

The Rain Thistle grows from a spray of thin-bladed leaves at its base, from which a handful of tall, tough stems grow. These stems are covered in more brightly colored, frill-edged leaves which help channel water to the base of the plant. One of these stems is typically crowned with a flower of spiky and unusually hard-skinned petals.

During rainstorms, this thistle-like flower opens to reveal a soft, fibrous “boll” within. This is a seedpod surrounded by strong, absorbent fibers. The opening action promotes pollination in ideally wet conditions and allows the plant to absorb and store water in its fibers. This water storage mechanism helps the plant thrive in typically rocky growing mediums, without moist soil.