Translation guide
The central shaft of a compound leaf or inflorescence; also refers to the spine of a feather. In Japanese, different terms are used depending on the context (botany vs. ornithology).
The main stem or axis of a compound leaf (e.g., fern frond, palm leaf) or the central stalk of an inflorescence.
General term for the rachis of a compound leaf. Used in botanical contexts.
The central shaft or spine of a feather, from which the barbs extend.
The standard term for the rachis of a feather.
The sporangia are attached to the rachis of the fern.
Specifically the rachis of an inflorescence (flower cluster).
The rachis of this plant's inflorescence grows long.
Literally 'central axis', can be used for rachis in a broader sense, but less specific than 葉軸.
The leaflets are arranged along the central axis of the leaf.
羽軸が折れた羽は飛ぶのに支障がある。
A feather with a broken rachis hinders flight.
Another term for the shaft of a feather, sometimes used interchangeably with 羽軸, but can also refer to the quill (calamus).
The base of the feather shaft is embedded in the skin.