Hooker's orchid is an erect forb, 2-4dm tall, with sessile flowers that are yellowish-green and ascending. Its 8-12mm lip is lance-triangular, directed outward and upcurved. Its lateral sepals are widely reflexed behind the flower, alongside the ovary and the lateral petals are lanceolate, incurved, and may or may not be adjacent to the upper sepal. The spur is 13-25mm, directed downward, and tapering to the tip. Its fruit are ridged capsules, erect, more or less sessile, and tapering on both ends, glabrous. It has two leaves that are basal, prostrate, 6-12cm, and broadly elliptic to rotund, seldom narrower.
Its bractless stem and sessile ovary are distinguishing characteristics.