biforine

from The Century Dictionary.

• noun In botany, a minute oval sac found in the interior of the green pulpy part of the leaves of some araceous plants, with an aperture at each end through which raphides are expelled.

from the GNU version of the Collaborative International Dictionary of English.

• noun (Bot.) An oval sac or cell, found in the leaves of certain plants of the order Araceæ. It has an opening at each end through which raphides, generated inside, are discharged.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun botany An oval sac or cell, found in the leaves of certain araceous plants, with an opening at each end through which raphides, generated inside, are discharged.