| rhachis | Origin: See Rachis Alternative forms: rechis. 1. <anatomy> The spine. 2. <botany> The continued stem or midrib of a pinnately compound leaf, as in a rose leaf or a fern. The principal axis in a raceme, spike, panicle, or corymb. 3. <zoology> The shaft of a feather. The rhachis of the after-shaft, or plumule, is called the hyporhachis. The central cord in the stem of a crinoid. The median part of the radula of a mollusk. A central cord of the ovary of nematodes. Source: Websters Dictionary (01 Mar 1998) |
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