Meanings of pinnule in English

Stem and branches pinnate or bipinnate, the pinnae and pinnules alternate.

When disturbed, the pinnules of the arms first contract, the arms straighten themselves out, and the whole gradually and slowly closes up.

Colour bright brown, rachis shining, very dark brown; polypidom about six inches high, simply pinnulate, pinnules about half an inch; thickly and regularly disposed, alternate.