dryoptaris, with an a

That e is the second syllable of pteris, the Greek word for fern, which in turn comes from pteron, a feather or a wing. The frond of a male fern is a good enough feather to justify the name. Both of those Greek words keep an e in the middle and pass it on to every botanical name built from them, which is a large family: Cystopteris, Phegopteris, Polypodium's neighbours on any woodland bank. Once you have spotted the pteris in a fern name, the vowels in it stop being a guess.

An unstressed vowel, flattened until it gives the ear no information.