American Heritage Dictionary of the English Language, 5th Edition
From New Latin, from Ancient Greek ῥάχις (rhakhis, “spine, ridge").
Rachis Sentence Examples
Seed, attached to a branch of the rachis bearing two vegetative leaflets.
With regard to birds and land shells the relation is much closer to the Comoros species, and the latter, of which I have collected seven species besides Rachis aldabrae, may serve to point out more than the birds the land connexion of Aldabra with the neighbouring countries."
The ripe ears of the last hang so as to become almost parallel with the stem; they are narrower and longer than in (b), owing to the grains being placed farther apart on the rachis; it includes the Chevalier variety, one of the best for malting purposes.
All the flowers of each triplet of spikelets on both sides of the rachis are fertile and produce ripe fruits; hence the ear produces six longitudinal rows of grain.
All the flowers of each triplet are fertile as in (ii.), but the rows are not arranged regularly at equal distances round the rachis.