• Webster's Revised Unabridged Dictionary
    • Rhachis (Zoöl) A central cord of the ovary of nematodes.
    • Rhachis (Zoöl) The central cord in the stem of a crinoid.
    • Rhachis (Bot) The continued stem or midrib of a pinnately compound leaf, as in a rose leaf or a fern.
    • Rhachis (Zoöl) The median part of the radula of a mollusk.
    • Rhachis (Bot) The principal axis in a raceme, spike, panicle, or corymb.
    • Rhachis (Zoöl) The shaft of a feather. The rhachis of the after-shaft, or plumule, is called the hyporhachis.
    • Rhachis (Anat) The spine.
    • ***
Century Dictionary and Cyclopedia
    • n rhachis See rachis.
    • ***


Webster's Revised Unabridged Dictionary
See Rachis


In literature:

Leaflets lanceolate, with acuminate apex; rhachis glabrous.
"Northern Nut Growers Association Thirty-Fourth Annual Report 1943" by Various
One spikelet of each pair sterile and shortly pedicelled, the other fertile, sessile and sunk in the rhachis.
"The Manual of the Botany of the Northern United States" by Asa Gray