Leaves - Shape Part 1

Upon close examination, the key similarities are evident, but why does one tree produce such marked variations in leaf shape? Pursuit of an answer to this question opened the door to the absorbing world of leaves.

Vocabulary of Leaf Shapes

Before we can talk about what shape a leaf is, we need to know what to call the shape. All of us refer to the myriad leaf shapes we encounter by some name...round, long, narrow, pointed...but the world of botany has taken this vocabulary to a much finer level, assigning specific names for the overall shape of leaves, their edges, their form and the way they are attached to the stem.

We encounter these terms describing the morphology (shape) of leaves when we research plants as they are used as frequently as botanical binomials because of their accuracy.

Some of these descriptive terms are easy to remember and associate with the appropriate shape; some are not, at least for me, as they refuse to stick in my brain. But, like botanical names, continued encounter with them eventually embeds them to the point of recognition.

Some of them are fairly obvious:

lanceolate = lance-shaped (longer than wide, broader at base, narrower at tip)
ovate = egg-shaped (more or less rounded at both ends, widest at the bottom)
elliptical = ellipse-shaped (narrow at each end, widest in the middle)
spatulate = spoon-shaped

Some are not as familiar:

cordate = heart-shaped (petiole [leaf stem] attached to the center of the rounded end)
auriculate = having ear-shaped lobes at the base of the leaf