| 释义 |
ra·chis
\ˈrākə̇s\ noun
(plural rachises \-sə̇z\ ; or rach·i·des \ˈrakəˌdēz, ˈrāk-\)
Etymology: New Latin rachid-, rachis, modification of Greek rhachi-, rhachis — more at rachi-
1. : vertebral column, spine
2. : any of various axial structures: as
a.
(1) : the elongated axis of an inflorescence
(2) : the extension or prolongation of the petiole bearing the leaflets of a compound leaf
b.
(1) : the distal part of the shaft of a feather that bears the web
(2) : the central cord in the stem of a crinoid
(3) : the median part of the radula of a mollusk that bears the central teeth
(4) : a central cord of the ovary of nematodes
(5) : the distal part of the shaft of a sea pen or similar organism |