What are carnivorous plants?

The famous historical naturalist, Charles Darwin described carnivorous plants as “The most wonderful plants in the world”. The Swedish botanist Carl Linnaeus is quoted on carnivorous plants, “to think that plants ate insects would go against the order of nature as willed by God”. Against God’s will or not, we now know that Carnivorous plants are plants that eat small insects and animals. They thrive in wet, humid and nutrient poor environments. They trap and digest small invertebrates as a source of nitrogen to compensate the lack of nutrients in their habitat. Scientists believe that the carnivory gave them the evolutionary advantage to grow in such nutrient poor environments where most other plants cannot survive. Most of you may naturally think that carnivorous plants are from warm tropical rain forests. However, they grow all over the world except antarctica. In fact, we do have 3 genera and 14 species of carnivorous plants in Rhode Island! They can be found in bogs, ponds and wetlands all around RI.

Sarracenia

The genus Sarracenia is also known as American pitcher plants. As the name suggests, they grow in North America and Canada. They employ pitcher shaped pitfall traps to capture their prey. The underside of the lid as well as the lips of the traps produce nectars that attract many insects such as flies and wasps. The prey falls into the trap because these parts of the plants are slippery. The prey won’t be able to get out of the trap easily, because the hairs inside the trap grow downwards, and they will eventually be digested. Sarracenia are not known for enzymatic digestion, but rather rely on fermentation by bacteria and fungi. There are thought to be 8 distinct species (not including variations) of Sarracenia occurring in eastern coast of the United States. S. purpurea is the only northern species and therefore is the only one you can find in RI.

Drosera

Drosera, aka sundews use glue traps to capture insects. Their leaves have numerous glands that secrete sticky nectar with digestive enzymes. The insects that are attracted to the nectar will be “glued in” on the trap. All the surrounding glands will eventually bend in to cover the entire body of the prey. This process has been extensively described by Charles Darwin in his book “Insectivorous Plants”. Drosera occur in every continent except antarctica. About 250 species have been discovered so far. But the numbers are increasing. We have 3 species of Drosera in RI, D. rotundifolia, D. filliformis (State Historical) and D. intermedia.

 

Utricularia

Utricularia, aka bladderwort are rootless, semi-aquatic to fully aquatic, and rather inconspicuous plants. However, they use the most complex bladder shaped traps to capture their prey. Like Drosera, there are roughly 250 species of Utricularia found in every continent except antarctica. A bladder trap is like a small bag with a door. The bladder actively transport water out to create a negative pressure inside it. When a prey bends the sensitive hairs on the trap door, the door opens, thereby sucking the prey within. This movement is considered to be the fastest in the entire plant kingdom! We have 10 species of Utricularia in RI, 3 terrestrial species: U. cornuta, U. resupinata, and U. subulata, and 6 aquatic species: U. intermedia, U. minor, U. vulgaris, U. radiata, U. purpurea, U. geminiscapa, and U. gibba.

 

Emmi Kurosawa, the New England Carnivorous Plant Society

New England Carnivorous Plant Society

Special Thanks

to the

New England Carnivorous Plant Society

and to

Emmi Kurosawa

 

The mission of the New England Carnivorous Plant Society shall be to share, to gain knowledge of, and to achieve expertise in all phases of growing, education, appreciation, and conservation of carnivorous plants in both culture and in native habitats.

The information on Rhode Island Carnivorous Plants comes from several sources. The blooming dates are based on Seymour’s “Flora of New England.” The county and status information is from Rick Enser’s Rare Plants of RI 2007 and RI Wildlife Action Plan 2015, Appendix 1d, and, for plants not on the Rare Plant List, the status is taken from Gil George’s Rhode Island Botanical Survey Check List, published in 1999. Francis Underwood provided habitat information.

Table of Contents

If you know where you want to go,
click on the genus or species listed below.

For a key to the status codes, click here.

To down load a pdf (3.73 mb)of
RI Carnivorous plants
click here.

Click on the thumbnail image to view a larger photo.

Sarracenia
Sarraceniaceae—Pitcher-plant family

Pitcher Plant

      
Botanical Name:   Sarracenia purpurea
Common Name:   Purple Pitcherplant, Indian Dipper, Side-saddle Flower
   
Habitat:   sphagnum bogs, sandy or marly shores
Flowers:   (5/30) June 16-July 26
   
State Status:   O
     
Counties found in:   KE, PR, WA

Close-up of pitcher

Top photo:
Pitcher Plant
Photo credit: © Francis R. Underwood 2019

Photo at left:
Close-up of pitcher
Photo credit: kbarton

Reddish Pitchers

 

Reddish Pitchers
Photo credit: © Emmi Kurosawa 2019

 

Pitcher Plant with blossoms

 

 Pitcher Plant with blossoms
Photo credit: © Francis R. Underwood 2019

Pitcher Plant in marsh

 

Pitcher Plant in marsh
Photo credit: © Francis R. Underwood 2019

Pitcher Plant bud

 

 Pitcher Plant bud
Photo credit: kbarton

Pitcher Plant bud opening

 

Pitcher Plant bud opening
Photo credit: © Francis R. Underwood 2019

Stamens of Pitcher Plant

Stamens of Pitcher Plant
Photo credit: kbarton

 

Drosera
Droseraceae—Sundew family

Drosera filiformis plant with seeds
Botanical Name:
   Drosera filiformis
Common Name:
   Thread-leaved Sundew, Red-rot
   
Habitat:
   Shallow ponds and streams
Blooming Date:
   July 4-August 26
 
State Status:
   SH
   
Counties w/sites
   WA

Drosera filiformis in group

 

Top photo:
D. filiformis plant with seeds
Photo credit: © Emmi Kurosawa 2019

Photo at left:
D. filiformis in group
Courtesy W.D. and Dolphia Bransford,
Lady Bird Johnson Wildflower Center

Drosera filiformis leaf

 

D. filiformis leaf
Rosťa Kracík [CC BY 3.0 cz (https://creativecommons.org/licenses/by/3.0/cz/deed.en)]

Drosera filiformis --close-up of flower

 

 

D. filiformis--close-up of flower
Rosťa Kracík [CC BY 3.0 cz (https://creativecommons.org/licenses/by/3.0/cz/deed.en)]

Drosera filiformis flower stalk

 

D. filiformis flower stalk
Rosťa Kracík [CC BY 3.0 cz (https://creativecommons.org/licenses/by/3.0/cz/deed.en)]
 
Dragonfly captured by Spatulate-leaved Sundew
Botanical Name:
   Drosera intermedia
Common Name:
   Spatulate-leaved Sundew
   
Habitat:
   wet places, shallow water
Blooming Date:
   (7/10-8/11
 
State Status:
   C
Sites in State:
    
Counties w/sites
   KE,NE, PR,WA

Drosera intermedia plant

 

Top photo:
Dragonfly captured by Spatulate-leaved Sundew
Photo credit: © Emmi Kurosawa 2019

Photo at left:
D. intermedia plant
Photo credit:©David G. Smith,
http://www.delawarewildflowers.org

Drosera intermedia flower

 

D. intermedia flower
Photo credit: ©David G. Smith,
http://www.delawarewildflowers.org

Drosera intermedia with flower stalk

 

 D. intermedia with flower stalk
Photo credit: Hajotthu [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]>
 

Drosera rotundifolia flowers
Botanical Name:
   Drosera rotundifolia
Common Name:
  

Round-leaved Sundew,
Dew-plant, Moor-grass
     
Habitat:
   Bogs and swamps
Blooming Date:
   June to August
 
State Status:
   C
     
Counties w/sites
   All

 

Drosera rotundifolia plant with captured moth

Top photo:
D. rotundifolia flower
Photo credit: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Photo at left:
D. rotundifolia plant with captured moth
No machine-readable author provided. NoahElhardt assumed
(based on copyright claims). [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]

 

Drosera rotundifolia--close up of leaf

 D. rotundifolia--close up of leaf
Photo credit: Petr Dlouhý [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0/)]

 

Drosera rotundifolia --close up of "dew" on leaf

 D. rotundifolia --close up of "dew" on leaf
Photo credit: © Emmi Kurosawa 2019.

 

Drosera rotundifolia buds and seeds

 D. rotundifolia buds and seeds
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info
 

Utricularia
Lentibulariaceae—Bladderwort Family
Utricularia cornuta -- flowers
Botanical Name:
   Utricularia cornuta
Common Name:
   Horned Bladderwort
   
Habitat:
   wet shores, out of water on low grounds
Blooming Date:
   7/2-9/12
 
State Status:
   U
     
Counties w/sites
   PR, WA

Utricularia cornuta -- close-up of spur

 

Top photo:
U. cornuta -- flowers
Photo credit: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Photo at left:
U. cornuta -- close-up of spur
Photo credit: © Emmi Kurosawa 2019

Utricularia cornuta plants in wetland

 

 U. cornuta plants in wetland
Photo credit: Costea, M.and Costea ,G. PhytoImages.
Available from: http://www.phytoimages.siu.edu
 
Utricularia geminiscapa flower
Botanical Name:
   Utricularia geminiscapa
Common Name:
   Mixed Bladderwort
   
Habitat:
   quiet water, sandy shores
Blooming Date:
   7/15-9/2
 
State Status:
   SC
     
Counties w/sites
   KE, PR, WA

Utricularia geminiscapa plant

 

Top photo:
U. geminiscapa -- flower
Photo credit: © Emmi Kurosawa 2019

Photo at left:
U. geminiscapa --plant
Photo: John Thayer, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Utricularia geminiscapa sepals and bracts

 

 U. geminiscapa sepals and bracts
Photo: John Thayer, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Utricularia geminiscapa -fruit from cleistogamous flowers

 

 U. geminiscapa -fruit from
cleistogamous flowers
Photo: John Thayer, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/
 
 

Utricularia gibba -- close up of flower
Botanical Name:
   Utricularia gibba
Common Name:
   Creeping Bladderwort
   
Habitat:
   shallow water
Blooming Date:
   9/1-10/9
 
State Status:
   SC
     
Counties w/sites
   KE, PR, WA

Utricularia gibba flower

 

Top photo:
U. gibba -- close up of flower
Photo credit: ©David G. Smith,
http://www.delawarewildflowers.org

Photo at left:
U. gibba flower
Photo credit: © Emmi Kurosawa 2019

Utricularia gibbaplant

 

 U. gibba -- plant
Photo credit: ©David G. Smith,
http://www.delawarewildflowers.org

Utricularia gibba -- Submerged branch with forked leaves and two bladders

 

 U. gibba -- Submerged branch with
forked leaves and two bladders
Photo credit: ©David G. Smith,
http://www.delawarewildflowers.org
 

Utricularia intermedia flower
Botanical Name:
   Utricularia intermedia
Common Name:
   Flat-leaved Bladderwort
   
Habitat:
   hallow waters, muddy soil on drawn down pond shores
Blooming Date:
   6/5-8/4
 
State Status:
   SC
     
Counties w/sites
   WA (reported)

Utricularia intermedia -- close up of flower

 

Top photo:
U. intermedia -- close up of flower
Photo: Peter Dziuk, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Photo at left:
U. intermedia -- close up of flower
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia intermedia -- foliage

 

U. intermedia -- foliage
Photo credit: © Emmi Kurosawa 2019

Utricularia intermedia -- close up of leaf

 

U. intermedia -- close up of leaf
hoto: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

 

Utricularia intermedia -- turion

 

U. intermedia -- turion*
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

 

* Some of the aquatic species produce turions (or “winter buds”) at the apices of branches. These consist of very short internodes with tightly compacted overlapping dissected leaves and a mucilaginous matrix. Turions are often conspicuous toward the end of the summer and in U. vulgaris, at least, have been shown to be induced by environmental change to short day lengths.

The above excertped from Michigan Flora
https://michiganflora.net/genus.aspx?id=Utricularia

 
 

Utricularia minor -- close-up of flower
Botanical Name:
   Utricularia minor
Common Name:
   Lesser Bladderwort
   
Habitat:
   shallow water
Blooming Date:
   5/27-718
 
State Status:
   SH
   
Counties w/sites
   —

Utricularia minor -- flower stalks

 

Top photo:
U. minor -- close-up of flower
:Photo: Peter Dziuk, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Photo at left:
U. minor -- flower stalks
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia minor -- plants

 

U. minor -- plants
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

-- leaves

 

U. minor -- leaves
Photo credit:© Emmi Kurosawa 2019

Utricularia minor--bladders

 

 U. minor -- bladders
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia minor--turion

 

 U. minor -- turion*
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

 

* Some of the aquatic species produce turions (or “winter buds”) at the apices of branches. These consist of very short internodes with tightly compacted overlapping dissected leaves and a mucilaginous matrix. Turions are often conspicuous toward the end of the summer and in U. vulgaris, at least, have been shown to be induced by environmental change to short day lengths.

The above excertped from Michigan Flora
https://michiganflora.net/genus.aspx?id=Utricularia
   

 
 

Utricularia purpurea flowers
Botanical Name:
   Utricularia purpurea
Common Name:
   Eastern purple Bladderwort
   
Habitat:
   quiet water
Blooming Date:
   7/6-9/6
 
State Status:
   U
   
Counties w/sites
   KE, PR, WA

Utricularia purpurea -- close up of flower

 

Top photo:
U. purpurea flowers
:Photo: Peter Dziuk, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Photo at left:
U. purpurea -- close up of flower
Photo credit: ©David G. Smith,
http://www.delawarewildflowers.org

Utricularia purpurea -- flower stalk

 

U. purpurea -- flower stalk
Photo credit: © Emmi Kurosawa 2019

 

Utricularia purpurea--leaves and bladders

 

U. purpurea--leaves and bladders
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

 
     
 

Utricularia radiata--close up of flower
Botanical Name:
   Utricularia radiata
Common Name:
   Floating Bladderwort
   
Habitat:
   floating on surfaces of ponds
Blooming Date:
   7/4-10/12
 
State Status:
   U
:
    
Counties w/sites
   KE, NE, PR, WA

Utricularia radiata plant

 

Top photo:
U. radiata--close up of flower
Photo credit :Alan Cressler,
Lady Bird Johnson Wildflower Center

Photo at left:
U. radiata plant
Photo credit :Alan Cressler,
Lady Bird Johnson Wildflower Center

Utricularia radiata --plants in habitat

 

U. radiata --plants in habitat
Photo credit: © Emmi Kurosawa 2019

 

Utricularia resupinata -- Flower
Botanical Name:
   Utricularia resupinata
Common Name:
   Resupinate Bladderwort
   
Habitat:
   muddy soil, drawn down ponds with sandy substrate
Blooming Date:
   7/14-9/22
 
State Status:
   SC
   
Counties w/sites
   KE, WA

Utricularia resupinata -- close-up of flower

 

Top photo:
U. resupinata -- Flower
Photo credit :Alan Cressler,
Lady Bird Johnson Wildflower Center

Photo at left:
U. resupinata -- close-up of flower
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia resupinata -- two views of the flower

 

U. resupinata -- two views of the flower
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia resupinata -- flower stalk

 

U. resupinata -- flower stalk
Photo credit: © Emmi Kurosawa 2019

 

Utricularia resupinata -- glands

 

U. resupinata -- glands
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

 

Utricularia resupinata -- bladders

 

 

U. resupinata -- bladders
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia resupinata -- leaves

 

U. resupinata -- leaves
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/
 

Utricularia subulata flower
Botanical Name:
   Utricularia subulata
Common Name:
   Slender Bladderwort, Zig-zag Bladderwort
   
Habitat:
   wet soil, shallow water
Blooming Date:
   8/30-9/15
 
State Status:
   SC
   
Counties w/sites
   PR

Utricularia subulata plants

 

Top photo:
U. subulata flower
Photo credit: © Emmi Kurosawa 2019

Photo at left:
U. subulata plants
Photo: Noah Elhardt [CC BY-SA 3.0
(http://creativecommons.org/licenses/by-sa/3.0/)]

 
 

Utricularia vulgaris flowers
Botanical Name:
  

Utricularia vulgaris (https://gobotany.nativeplanttrust.org/) or
Utricularia macrorhiza (USDA)
Common Name:
   Common Bladderwort, Greater Bladderwort
   
Habitat:
   quiet water
Blooming Date:
   7/9-9/6
 
State Status:
   F
   
Counties w/sites
   KE, NE, PR, WA

Utricularia vulgaris plants

 

Top photo:
U. vulgaris flowers
Photo: Peter Dziuk, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Photo at left:
U. vulgaris plants
Photo: Peter Dziuk, via Minnesota Wildflowers,
https://www.minnesotawildflowers.info/

Utricularia vulgaris leaves

 

U. vulgaris leaves
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

Utricularia vulgaris turion

U. vulgaris turion*
Photo: Peter Dziuk, via Minnesota Wildflowers, https://www.minnesotawildflowers.info/

 

 

* Some of the aquatic species produce turions (or “winter buds”) at the apices of branches. These consist of very short internodes with tightly compacted overlapping dissected leaves and a mucilaginous matrix. Turions are often conspicuous toward the end of the summer and in U. vulgaris, at least, have been shown to be induced by environmental change to short day lengths.

The above excertped from Michigan Flora
https://michiganflora.net/genus.aspx?id=Utricularia

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