Primary pinna

(Bot.) one of those portions of a compound leaf or frond which branch off directly from the main rhachis or stem, whether simple or compounded.

See also: Primary

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
An alternative explanation would be that some of these forms are actually intercalated on a primary pinna rachis.
2 mm wide, that are separated by 3-6 cm, depending on position on the primary pinna.
Full browser ?