Aira praecox is a species of grass known by several common names, including early hair-grass,<ref name=BSBI07>Template:Cite web</ref> yellow hairgrass and spike hairgrass. It is native to Europe. It also grows in North America as an introduced species, where it can be found on the east and west coasts in sandy or rocky areas, such as beaches and roadsides. This is a tuft-forming annual grass growing up to about 25 centimeters in maximum height. The thin, narrow leaves are located at the base of the stem. It bears very small inflorescences of purple-tinted green bisexual spikelets.
It is an annual, forming low and small but numerous tufts. It flowers from April to June.