Bracts

You’ve read the word countless times but what, exactly, are bracts?

Bracts are specialized or modified leaves

Purplish-pink bougainvillea bracts surround tiny white flowers (Lumbar) CC BY-SA 3.0

Bracts are generally associated with a reproductive structure. That reproductive structure may be a flower, a cone, or an inflorescence. An inflorescence is a cluster of flowers. Bracts rarely look similar to other leaves on the same plant. They may be smaller, larger, a different shape, or a different texture.

Plants with bracts are said to be bracteate or bracteolate, while plants without bracts can be referred to as ebracteate or ebracteolate. Very small bracts are called braceoles or braclets. Botanically speaking, bracteole are any bracts that occur on a pedicel, instead of under it. Pedicels are the tiny stems that hold individual flowers within an inflorescence.

The presence of bracts, or lack thereof, can help you identify plants.

Many shaped bracts

The tiny leaves seen at the base of pineapples and dandelions are bracts. [Note that bracts are not the same thing as sepals. You can see the difference easily when looking at the base of a dandelion.]

​The delicious leaves that surround an artichoke flower are also bracts. Tiny banana flowers are protected by bracts.

Artichoke (Jamain) CC BY-SA 3.0

Bracts along a banana flower stalk surround the rows of flowers (Raul654) CC BY-SA 3.0

In many cases, what you think are flower petals are actually specialized bracts, called epicalyx. Dogwood, hibiscus, poinsettia, and bougainvillea are common examples of bracts looking like flowers. Occasionally, you may see an epicalyx formation in strawberry flowers.

Dogwood inflorescence showing four large white bracts and a central flower cluster (Wikipedia) Public Domain

The whorl of short green leaves that surround the base of many flowers, such as sunflowers, is made up of bracts. This particular arrangement of bracts is called an involucre. 

Peace lily clearly showing the spadix and spathe (JJ Harrison) CC BY-SA 3.0

Two large bracts coming together, or one large bract forming a sheath, is called a spathe. Iris, crocus, and palm spathes enclose flower structures as they develop. Peace lilies form flowers on a spike, called a spadix, which is shielded by a large white spathe.

​Grass family bracts

​Cereal grains, such as wheat and millet, and the grasses found in your lawn, have tiny florets that are held in a pair of bracts. The upper half is called the palea and the lower half is called the lemma. Each group of grass flowers, called spikelets, also have a pair of bracts, called glumes, at the base. When grain is winnowed to remove the chaff, the chaff being removed is made up of those bracts.

Bracts of a grain spikelet (Aelwyn) CC BY-SA 3.0

Conifer bracts

Pine cones are covered with scales used to protect seeds. Female cones have two types of scales, bract scales and seed scales. Bract scales grow under seed scales. This positioning is called subtending. Bract scales are more obvious at the time of pollination. Very often, seed scales will grow over bract scales as seeds mature.

​The next time you walk past a flower, take a moment to enjoy its fragrance and see if you can spot the bracts, while you’re at it.

Because now you know.