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Carnivorous Plants
By Eleanor Dietrich

North Florida has many different kinds of carnivorous plants. In fact, the southeastern coastal plain is the richest area in North America in both number of species and total population of plants, containing about 90% of the species in the US and Canada. In North Florida, there is documented evidence of 12 species of bladderworts (Utricularia), 6 species of butterworts (Pinguicula), 6 species of pitcher plants (Sarracenia), 5 species of sundew (Drosera), and the Venus Flytrap which was planted in scattered locations, for a total of 30 species. Some of the more common species are included on this web site.

Carnivorous plants have adapted to nitrogen-poor soil conditions, trapping small insects and animals and digesting them to obtain needed nutrients. Moist and acid conditions are where you will most often find them, most common in savannahs and bogs which may be found in our area.

Carnivorous plants have basically four kinds of traps. Active traps, where there is motion in the trapping, have closing traps as in the Venus Flytrap, and trap doors, as in the bladderworts. Passive trap types consist of pitfalls, as in the pitcher plants, and sticky traps as in the butterworts and sundews. The three families and five genera discussed here illustrate each of the trap types.

bladderworts

butterworts

Pitcher Plants

sundews

Venus Flytrap

Photographic images are included for each of the 13 species included here (all images copyrighted by Eleanor Dietrich). You can click on one of the images above to move quickly to a section that interests you. Included at the end of these pages is a list of Other References such as books and websites that you may also want to visit.

Bladderwort Family (Lentibulariaceae)

Bladderworts (Utricularia)

There are 12 species of bladderwort in North Florida, two of which are shown here. It is more widespread than any other species of carnivorous plant. It is not as well known as some of the other genera, perhaps because it is less showy and dramatic. Bladderworts may be aquatic or terrestrial, growing in damp, sandy, acid soils and quiet acid ponds and bog waters. Most of the flowers are yellow, although a few are purple and one is white.

Bladderwort traps are, as their name suggests, small bladders. Each bladder has a small opening with a door. The bladder maintains a suction inside, and when a tiny animal or insect brushes against one of the fine trigger hairs around the opening, the door opens and the suction pulls the prey into the bladder, the door closing back quickly. Digestion then occurs over the next several days.

Horned bladderwort (U. cornuta) This plant grows in moist places and bogs and has its roots in the ground. It has yellow flowers with prominent spurs pointing downwards. There are 3-5 flowers per stalk and it can be 30 cm tall. Its flower stalk is green and its flowers are a bit larger than the similar U. juncea which has a shorter purplish flower stalk. It blooms April - October.

Swollen bladderwort (U. inflata) This plant floats on the surface of acid ponds and ditches or slow streams. Its flotation device is up to 25 cm across and located on the midpoint of the flower stalk, floating like spokes (4-10). The end of each "spoke" has bladders and there is also a large underwater system of bladders. There are 3-7 flowers per stalk that bloom from February - April. U. radiata is very similar in form but smaller, with its spokes only 6-8 cm across.

Butterworts (Pinguicula)

There are 6 species of butterworts in North Florida, 3 of which are shown here. Most butterworts grow in damp, sandy soil, although one species is often found along the edges of streams where it is subject to flooding. And all but one species have various shades of lavender flowers, the exception being the larger showy yellow butterwort. Butterworts have a single flower per stalk. The 3 lower petals form the lower lip, and may be divided. At the base of the petals, or corolla, it narrows into a tube ending in a spur. Inside the lower lip is a bearded palate that often projects outward or is "exerted."

Butterworts get their name from the texture of their leaves. "Pinguis" means fat in Latin, and "ula" means little one. They have a flat rosette of usually pale yellow-green stalk less leaves that sometimes curl up on the edges. Tiny glands on the leaves exude a sticky substance which traps small insects that land on the leaves. This substance has a greasy, or buttery, feel to our touch.

	Small butterwort (P. ionantha) This particular butterwort is found only in one small area and can be distinguished by the ring of deeper violet around the tube entrance. Another similar small lavender butterwort is P. primuliflora which is often found along stream edges.
	Violet butterwort (P. caerulea) These beautiful and showy flowers are 2.5-3 cm across and their petals often have extensive venation of a deeper violet. The palate beard is exerted and greenish yellow to cream in color. The pale green leaf rosettes are 5-10 cm across and the leaf edges are often sharply curled. They grow along the coastal plain from mid-Florida east.
	Yellow butterwort (P. lutea) This is our largest butterwort and its bright color makes it easy to spot. There are often several plants growing together. The flowers are 2.5-3.5 cm across. The pale green leaves are in rosettes, and often have rolled edges. It grows in open, damp, sandy places all along the southeastern coastal plain from Louisiana to North Carolina.

Pitcher Plant Family (Sarraceniaceae)

There are 6 species of pitcher plant in North Florida, 5 of which are shown here. The family, which has only one genus, Sarracenia, is named after Dr. M.S. Sarrazin of Quebec. They are our largest and showiest carnivorous plants, and therefore often the most well known. Pitcher plants are found throughout eastern North America, with one species in California. Most pitcher plants have very distinctive forms, making their identification fairly straightforward, but they also tend to hybridize, which complicates the situation considerably in some instances.

Pitcher plants have tubular trap leaves with a lid or trap at the top. The leaves may either stand erect or lie flat on the ground. The pitchers have bright coloration and nectar along the margins of the hood, which attract insects. Once the insect arrives and enters the top of the pitcher, it encounters stiff downward pointing hairs that make its descent into the trap easy, and making it very difficult to climb back out.

Pitcher plants grow in bogs and savannahs. They have large showy flowers that often open before their leaves are present. The flower structure is quite unusual. Each tall stalk has a large, single flower that opens facing downward. The top of the pistil is expanded into a large upside down umbrella-like structure with 5 points around the edges. The large petals, which may be yellow, pink, or dark red, hang down between these points with the stamens inside the umbrella. The sepals and "umbrella" remain long after the petals drop, and may assume an upright position.

	Purple pitcher plant (S. purpurea) This plant is particularly widespread in the northeast US and Canada, but we have many plants in North Florida. The leaf pitchers lie flat on the ground with wide openings at the mouth which collect rain water and may trap prey by drowning. The hood has stiff downward pointing hairs and the color varies from green to red. The large flowers are a beautiful pink color.
	Hooded pitcher plant (S. minor) To me, colonies of this plant look like humorous gatherings of aliens. The hood grows up over the pitcher and the back of the hood has light patches. These patches may fool insects thinking they are going to an opening. The plant tends to grow in drier areas and may be found in pine woods. The flowers are a pale yellow-green in color.
	Parrot pitcher plant (S. psittacina) The pitchers of this plant also lie on the ground and the hood is almost closed, its shape resembling a parrot's beak. Its leaves can turn quite red when growing in the sun. Its flowers are a bit smaller than other pitcher plants, and are a very deep red.
	Trumpet pitcher plant (S. flava) This is a very showy plant that can grow over large areas. It has many different color forms. The most common is a pale green with a large maroon splotch on the inside of the pitcher throat. Red pitchers and pitchers with red venation are also common. The flowers emerge before the leaves and are a striking chartreuse in color.
	White top pitcher plant (S. leucophylla) This plant is also tall, showy and locally abundant. The large flared hood of white with red venation gives it its name and makes it easy to spot. The large flowers are deep red and emerge before the leaves. It is unusual in that it produces a second crop of pitchers in late summer. Its only range is in west North Florida over to eastern Mississippi.

Sundew Family (Droseraceae)

Sundews (Drosera)

There are 5 species of sundews in North Florida, 2 of which are shown here. There are nearly 100 species worldwide. Sundews can be found throughout the eastern United States as well as on the west coast. Their leaves form a rosette pattern and may be upright or lie flat on the ground. Most sundew leaves have narrow stems ending in a broader blade that has been modified into a trap. Each trap section of a leaf is covered with small glands which secrete a sticky liquid substance, making the leaves look like they are covered with dew. "Droseros" is a Greek word meaning "glistening in the sun." The glands also secrete a nectar that lures insects to the leaves where they become stuck and food for the plant.

Sundew flowers are on a spike and there may be from 5 to 30 flower buds rolled up on the stalk. The flowers open one by one, beginning with the lowest bud and "unrolling" up to the last bud on the stalk. The flowers have parts in multiples of 5 --5 sepals, 5 petals, 5-10 stamens, and a 5-part ovary. The flower color varies from white to pink.

	Dew thread sundew (D. filiformis v. tracyi) This plant often forms large stands which makes it easier to see and the leaves can be up to 50 cm tall. It is the largest of the sundews. Its flowers are also large, up to 2 cm, and are always pink. The petals may have somewhat scalloped edges. It can grow in drier habitats than most other sundews.
	Pink sundew (D. capillaris) There are several of these small reddish sundews that can be hard to distinguish upon first glance. The leaves lie flat on the ground in rosettes, and the ends of the blades are rounded and covered with the sticky glands for trapping prey. The small flowers are usually light pink in color.

Venus Flytrap (Dionaea muscipula)

There is only one species in this genus, and it has been planted in North Florida, but seems to be doing well where planted. It is native to a small area of along the coast of southern North Carolina and northern South Carolina.
The plant is a rosette of leaves and it takes 3-4 years for it to grow large enough to flower, and a plant can live as long as 25 years. Nectar in marginal glands on the leaf trap attract prey to the trap. Inside each leaf there are 3 trigger hairs in a triangular pattern. When these hairs are stimulated, they signal the leaf trap to close. There are also large guard hairs on the margins of the leaves that mesh as the leave trap closes, making it more difficult for prey to escape. Digestion takes from 3 to 5 days, then the trap will reopen. There are about 3 meals in a leaf trap life.

Venus flytrap The rosette of leaves is 10-14 cm across when mature. The flower stalks can be up to 30 cm tall and there are multiple flowers to each stalk. The flowers have 5 white vented petals. Click on the picture at left for a large image of the flower.

Other References

The best book that I found is Carnivorous Plants of the United States and Canada by Donald E. Schnell, 2002. [Buy New] (There is also a 1976 edition which is out of print now. Buy Used on Amazon)

  Carnivorous Plants www.sarracenia.com/cp.html

Photographs Copyright © 1998-2008 Eleanor Dietrich
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