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Webster 1913 Edition

[L.

caducus

falling, inclined to fall, fr.

cadere

to fall. See

(Bot. & Zool.)

Dropping off or disappearing early, as the calyx of a poppy, or the gills of a tadpole.

Adj.

In botany, falling early; as caducous leaves, which fall before the end of summer. A caducous calyx falls before the corol is well unfolded.

caducous ‎(comparative more caducous, superlative most caducous)

(biology) Of a part of an organism, disappearing in the normal course of development.
- 1992, Rudolf M. Schuster, The Hepaticae and Anthocerotae of North America: East of the Hundredth Meridian, volume V, page 4
  The Jubulaceae have a leaf whose lobule, usually transformed into a water-sac, is normally very narrowly attached to the stem and to the dorsal lobe; indeed some Frullania taxa reproduce vegetatively by dropping the dorsal lobes, but not the lobules, and Neohattoria has caducous lobules but persistent lobes.
(botany) Tending to fall early.
caducous leaves