Savage Garden: Sarracenia Flowers

Carnivorous plants can be fascinating in their abilities to catch and consume prey, but perhaps the most bizarre adaptations can be found in the strange blooms of these plants.

About the Sarracenias

Sarracenias, known also as the trumpet pitcher plants can be found mostly in the North America southeast. One species, the Purple Pitcher Plant (Sarracenia purpurea), extends its range north all the way to Canada.

These plants have pitcher-shaped leaves that mimic flowers and attract insects with bright colors, sweet scents and sugary nectar that exudes from the lips of the pitchers. The steep walls, slippery surfaces, and downward pointing hairs inside of the pitchers ensure that insects that visit often end up in liquid at the bottom of the tube. This liquid is a soup of digestive juices, bacteria, and sometimes even the larvae of small insects, which all work together to break down and digest the unlucky prey. 

Now, onto my favorite part: In late spring, Sarracenia develop brightly colored, nodding flowers, which range in color from bright yellow to purple, red, or pink. The flower stalks grow rapidly, from first being noticed to tall and blooming in what seems to be just a few days. These blooms are brilliant colors, and unlike other blossoms, the are pendant. The faces of the flowers look down toward the boggy ground. 

First, let's talk a bit about pollination

For a flower to make seeds, it has to be pollinated, sometimes with pollen from that flower and sometimes with pollen from another flower of the same species. Here's a generic flower, labeled so you can see all of the inside parts.

For pollination to work, pollen needs to be collected from the anther and transferred to the stigma of the flower. This generally happens by an insect collecting pollen from the anthers of flowers and brushing against the stigma of that flower or another of its species, transferring pollen from the flower's male parts to the female parts. Once this happens a flower is considered pollinated and seeds will begin to slowly form in the ovary.

Those Crazy Sarracenia Flowers:

To better understand these flowers, here is a diagram of a Sarracenia flower cut in half so you can see all of the inside parts.

Just like in other flowers, Sarracenia need pollen to be transferred from the anther to the stigma. In this genus of flowers, there is a part called the style that is very enlarged compared to that part in other flowers. As the flower hangs over, facing down, the style acts like a large umbrella, catching all of the pollen that falls off of the anthers and stores it all in a convenient little pile, protected by the petals and sepals of the flower.

The scent of these flowers is musty and some flies are strongly drawn to the fragrance. Once arriving at the flower, however, it isn't the simple visit that other flowers offer. The Sarracenia flower turns into a bit of a maze for pollinating insects. Look closely at the image to the left. If you look just above the drooping petal in the front of the pictured flower and the sepal that works like a roof or awning, you can see a narrow spot of brighter yellow-green. Think of this tiny entrance as the flower's front door.

Once an insect gets inside the flower, it finds the style floor covered with drops of nectar that drip from the ovary. This nectar, of course, draws the insect right through a nice pile of waiting pollen. Once the insect has gotten its fill, exiting the flower forces the bug to brush against a stigma on the way out, pollinating the flower. In nature, an insect will likely have visited a bunch of these flowers which are all in bloom about the same time. Covered in the nectar of several or many flowers, insects move pollen between the flowers as they feed.

After pollination, the petals of the flower fall away, leaving the umbrella floor of the style, the ovary and the awning-like sepals to hang out while the ovary grows with the seeds inside.

From the look of it, this Purple Pitcher Plant (Sarracenia purpurea) was successfully pollinated inside our exhibit. We'll be keeping an eye out to see if the seeds do mature.

In cultivation, the flowers of Pitcher Plants are often pollinated by hand by a person using a small swab or tooth pick to transfer pollen. This allows nurseries to ensure that plants are producing the seeds of a particular species or are being crossed-pollinated through hybridization... but that will be a story for another day.

Carnivorous Plant Club, Rule 1: Don't Eat the Fly That Pollinates You

Something you might notice about these flowers is that you aren't seeing much of the 'pitchers' for which these plants are named. That's pretty important. Sarracenias flower right as the plant is coming back from winter dormancy, which the pitchers are still growing and forming. Our bed of Pitcher Plants is mostly just a bed of flowers right now, which helps to ensure that these plants are not consuming the very insects that they need to attract for pollination purposes. Once the flowers have been pollinated, we'll see a lot more pitchers opening up and we'll be sure to show you photos of that as well.

What's in a Name?

The genus Sarracenia is named for Dr. Michel Sarrazin, an 18th century botanist and physician from Quebec, Canada.

Current species on display include:

Yellow Pitcher Plant (Sarracenia flava)
White Pitcher Plant (Sarracenia leucophylla)
Purple Pitcher Plant (Sarracenia purpurea)
Hooded Pitcher Plant (Sarracenia minor)
Parrot Pitcher Plant (Sarracenia psittacina)
Sarracenia x 'Judith Hindle'
Sarracenia x 'Dana's Delight'
Sarracenia x Abandoned Hope'