Circinal: spirally rolled like a watch-spring or a butterfly tongue.
"Explanation of Terms Used in Entomology" by John. B. Smith
Most Ferns are circinate in the bud; that is, are rolled up in the manner shown in Fig.
"The Elements of Botany" by Asa Gray
Leaves circinate in vernation.
"The Manual of the Botany of the Northern United States" by Asa Gray