Pea Flower Parts (Banner, Keel, Wing, Banner Spot)

The Pea Family is one of the biggest in the Plant Kingdom. All pea plants have pea flowers and pea pods.

The pea flower is irregular. It combines 5 petals in an asymmetrical arrangement.

· The Banner petal curves back from the rest of the flower.

· Two Wing petals cover the reproductive parts, one from each side, and form a landing pad for pollinators.

· Inside the Wing petals are two fused Keel petals that wrap around the reproductive parts from below. The Keel is often entirely covered by the Wing petals.

Here’s a generic diagram for the Pea Flower:

Diagram from Wikimedia, by David Richfield, based on work by Wikipeda User:Aelwyn

Wondering about some of the other terms?

· The Pedicel is the stalk that connects the pea flower to the plant’s stem.

· The Calyx protects the flower while it is developing. As the flower blooms, the calyx opens into two pieces and eventually falls off.

· Stamens are male reproductive parts. The pistil is the female reproductive part. Pollinators gather pollen from one plant’s stamens and transfer it to another plant’s pistil.

All of these parts – banner, wing, keel, pedicel, etc. vary from species to species. It’s fun to examine them to decide which kind of plant you have.

Here’s a neat photo of a Hyacinth Lupine, showing pea flowers in both front and side views:

Hyacinth Lupine - Photo by Keir Morse

Notice that this species has a banner spot – a lighter colored spot in the center of the banner. Banner spots make a useful ID characteristic. The banner spot is also useful to the plant – this lighter color reflects ultra-violet light which provides a bulls-eye for pollinators flying in.

Next time you’re in the field, look at how your pea plant’s parts are arranged – color, shape, size, and so forth. Have fun with it!

Want more? See Thomas Elpel’s page on the Pea Family.

Corrections/Comments: bruce@PlantID.net