[2][3][4] The specific epithet, aestivalis, is derived from Latin and means "pertaining to the summer".

[5] It is epiphytic, with long and strong rhizomes that are firmly attached to its host.

The leaf sheaths range from ivory to white-yellow, and are spotted dark purple-brown.

The flower petals and sepals are greenish cream-yellow, and the labellums yellow-orange.

Unlike those found elsewhere, the E. aestivalis specimens from the Chatham Islands are not distinct, and seem to grade into E.