Leaf margins
Illustrations by Marina
Smelik
The leaf margin (edge of the leaf blade) can be very useful when identifying
plants. Like leaf shapes, you want to look at more than just one leaf to determine
its margin type. Some plants, like the tupelo tree illustrated below, will have
the majority of leaves on the plant without any lobes (leaf on the left). If
you check the plant carefully, you will find a few leaves with lobes (leaves
on the right).
Like
leaf shapes, there are also leaf margins that don't fit into a single category.
For example there are plants with crenate-serrate margins which are intermediate
between crenate and serrate. In general though, margins are fairly consistent
on a plant.
Tupelo
(Nyssa sylvatica) leaves from the same tree. About 99% of the leaves
I saw on this tree were like the leaf on the left; the other 1% were variously
lobed like the two leaves on the right.
BASIC
LEAF or LEAFLET MARGINS
Note: some leaves are divided into smaller units called leaflets. Margin
terms apply weather you are looking at a leaf or leaflet.
Entire
(smooth - no teeth or lobes)
Serrate
(teeth pointing forward)
Crenate
(teeth rounded)
Undulate
(wavy)
Double
serrate
Spinose
- main vein of tooth extends beyond leaf margin.
Pinnately
lobed
Palmately
lobed
A
lobe is an indentation in the margin at least 1/4 the distance from the margin
to the primary vein.
