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papilionacea, papilionaceous, irregular and spreading, somewhat like a butterfly, Lathyrus, t. 1108. The various petals which compose such a flower are distinguished by appropriate names, as vexillum, standard, the large one at the back; alœ, wings, the two side petals; and carina, the keel, consisting of two petals, united or separate, embracing the internal organs. In Trifolium all the petals are sometimes united into one at the lower part.

incompleta, incomplete, when parts, which analogy would lead us to expect, are deficient, as in Amorpha, a papilionaceous flower apparently, but consisting of the vexillum only; or Rittera of Schreber, a rosaceous one with a single lateral petal, seeming as if four others had been stripped off.

It is remarkable that irregular flowers sometimes vary to regular ones in the very same plant, as in Bignonia radicans, Curt. Mag. t. 485; and Antirrhinum Linaria, ''Engl. Bot. t.'' 658 and 260.

Linnæus was of opinion that the Corolla