Decompound Leaf of Meadow Rue

  • While ordinary leaves spread horizontally, and present one face to the sky and the other to the earth, there are some that present their tip to the sky, and their faces right and left to the horizon. Among these are the equitant leaves of the Iris or Flower-de-Luce. Inspection shows that each leaf was formed as if folded together lengthwise, so that what would be the upper surface is within, and all grown together, except next the bottom, where each leaf covers the next younger one. It was from their straddling over each other, like a man on horseback (as is seen in the cross-section), that Linnæus, with his lively fancy, called these Equitant leaves.

    The leaves of Iris just mentioned show one form of this. The flat but narrow leaves of Jonquils, Daffodils, and the cylindrical leaf of Onions are other instances. Needle-shaped leaves, like those of the Pine, Larch, and Spruce, and the awl-shaped as well as the scale-shaped leaves of Junipers, Red Cedar, and Arbor-Vitæ, are examples.