Crawe's sedge is a grass-like perennial that has long rhizomes and grows in patches. Stems mostly arise singly from the rhizomes and are 2-40 cm tall. Leaves are strap-like, clustered near the bases of the plants, and are 1.8-4.4 mm wide. Towards the apex of the stems are 3-5 narrowly cylindrical flower/fruit clusters (spikes). The terminal spike is composed of male flowers while the other spikes are composed of female flowers. The female flowers mature into fruits (perigynia) which are yellowish green to pale brown and 2.2--3.7 mm long (Cochrane and Naczi 2002).

Carex crawei is easiset to identify when the perigynia are just immature to mature but are not easily shedding.

Carex crawei is a fairly distinctive sedge. Its long rhizomatous and non-cespitose habit separates it from most other closely related species. It can also be distinguished from the closely related C. granularis by its longer staminate peduncles and lowest pistillate spikes arising on the lower half of the stems. In comparison, C. granularis has a shorter staminate peduncle and the lowest pistillate spikes arise on the upper half of the stems. Some members of section Paniceae grow in a similar habitat to C. crawei and may appear somewhat similar due to their elongated rhizomes. Members of section Paniceae usually have pistillate spikes with perigynia less densely arranged and with less that 25 perigynia per spike. In comparison, C. crawei has pistillate spikes with perigynia more densely arranged and with at least 25 perigynia per spike.