rachilla
/rəˈkɪlə/(also rhachilla) Botany
noun
In grasses: the floral axis, i.e. the axis on which the florets are borne within the spikelet. Also (in palms): the ultimate flower-bearing axis of the inflorescence.
Origin
Mid 19th century; earliest use found in William T. Brande (1788–1866), chemist. From scientific Latin rachilla from post-classical Latin rachis + -illa.