#bract

Bract (noun) – a modified leaf or scale

Bracts can be modified scales, like those in the cones of Douglas-fir featured in a post last week, but bracts can also be modified leaves. All three of the wildflowers pictured here don’t have colorful petals, but bracts!

The yellow “flower” of Skunk Cabbage (Lysichiton americanus) is a modified leaf. The bract’s hood-like shape helps keep heat around the spike of true flowers, allowing this plant to be the first wildflower of spring.

Scarlet Paintbrush (Castilleja miniata) get their color from bracts instead of petals. Note the leaves half-tinted in red lower along the stem. Paintbrush species can have bracts that are red, orange, yellow, and magenta pink!

The white bracts of Pearly Everlasting (Anaphalis margaritacea) give this plant its name. The true flowers are yellow, but the surrounding white bracts are stiff and dry – lasting for weeks and well into autumn.

No need for as much preamble, so today’s word is 

Bract

I love bracts, one of the many and most accessible tricky tricks of the of the plant world. Bracts are modified leaves that are associated with the flowering parts of plants. A lot of plants have them, and they are usually just hanging out well below the flower, but still along that same stem that the flower arises from (which is called a pedicel and honestly most plant part names are super fun and interesting, so if this continues I’ll cover a lot more). 

As is the case with all plant facts “usually” hardly covers anything, and showy bracts form the entire reason for one of the most popular annual plants folks buy and invite into their homes:

I feel like this is pretty common knowledge these days, with the advent of the internet, but the entire floral part of the poinsettia are the tiny bobbles in the middle there. The red “petals” around them are actually bracts that start green like the leaves they are, and stay green most of the year. Since the poinsettia flowers in the winter when days are short, the bracts respond to a photoperiod to draw in pollinators. Once they stop getting enough sunlight they begin the transformation from green to red, which is genuinely as pretty as fall color, just slowed way way down.

One of my formative horticultural memories was in High School when we (the FFA horticulture club which had a very small membership) ordered a large batch of totally green poinsettias from a grower and turned them ourselves for a christmas fundraiser. This mostly involved the advisor directing us handful of teens to put up and take down a shadecloth throughout the day, triggering the color shift faster than it would have happened naturally in Texas. 

11/18/2016