______________Drosera filiformis tracyi_________________

 

                                                              by Karla Sanders

 

                                        

                                        Thread-leaved Sundew springtime bloom

    Common name: Thread-leaved Sundew                                                       

The           

               Drosera filiformis tracyi is a carnivorous plant that is capable of photosynthesis,

               but acquires most of its nutrients through the digestion of insects. I owe the choice

               of sundew to my snake. Several Sundays ago I was feeding my California King snake

               his weekly pinkies and thinking about topics for this class.

 

                                                     

                                                     California King at work; the inspiration

                                                     www.westernfolklife.org/dofflemyer/2006/09/

 

 It occurred to me that I do not know much about carnivorous plants so I did a little research

 and chose one. I wanted to know how plants capture their prey, and found the Sundew’s

 method quite interesting. Is it immune to insect venom, like my snake Sweeney Todd, is to 

 most snake venom (he is a cannibal).  How does it capture its victims, and how long does

 digestion take? The sundew’s leaves can curl up around the insect, as if to strangle it, and

 as a constrictor snake lover, this caught my attention.

 

______________________Range and Habitat_________________________________________________________

                                          

The plant is a small wildflower found sparsely in coastal New England and more frequently

 to the south around the Gulf of Mexico in Florida and Louisiana. The species is also found in

Nova Scotia, but only in small amounts.

 

 

                                          

                                                           

                                                          Where to find Thread-leaf      green: present in this state…white absent    USDA.gov

 The plant only grows in bogs, and is tolerant of poor soils due to the animal proteins it collects from

 insects. Thread- leaved sundew is a perennial, herbaceous plant, that is known to only occur in five

 populations. The species are threatened by peat mines in their populations, and also by

cranberry farms(COSEWIC, 2002).

 

 _________________  Biology: How does Thread-leaved Sundew Eat?__________________________

 

 

                                          Thread-leaved sundew requires the use of hundreds of tiny

                                          tentacles to capture its prey. Each tentacle has a round gland

                                          that attracts insects. The “mucus” that secretes from the plant  

                                          gives sundew its name, as the plant looks very beautiful

                                          in the sunlight. However, to insects this secretion smells like

                                          food that lures them in. The sticky substance holds the insect

                                          in place while digestive enzymes work to dissolve soft tissues

                                          of the insect. The plant absorbs necessary nutrients through

                                          this process, leaving behind the exoskeleton. Total capture

                                          and digestion takes about five days to two weeks (Wexler, 1995).       

 

                                       

                                                                                                                    Victims  

                                                                                     www.weeksbay.org/.../wintemeyer/wintemeyer

 

 

                        One interesting study took a look at the ability of insects to escape from carnivorous plants.

                        The results for Drosera filiformis tracyi showed that insects with body sizes from 5 mm to

                        10 mm tend to escape; however, the plant is able to “eat” a wide range of insects (Gibson, 1991).

 

                        It does not seem to react to venomous insects, but how does the plant know what is editable           

                        and what must be left alone? Charles Darwin wondered if a sundew could be fooled.

                        Meaning, will a sundew try to digest objects other than insects? Objects with no nutritional

                        value do not stimulate the glands that send digestion messages through the plant. It is easy to

                        test Darwin’s question, and you will discover that tentacles might move to the touch of a

                        pebble, but take no action. The glands of the tentacles are made up of cells, and when

                        an insect entangles itself in the tentacles (the more it moves, the more tentacles it

                        becomes attached to), the cells send messages down the stalk of the plant, essentially

                        informing the entire tentacle structure to bend, as seen in the large image below (Wexler, 1995).

 

                       

                         Watch 37 seconds of some struggling flies!                 

                         thread-leaved sundew with prey

 

                       

 

                      note the tiny glands   http://www.bestcarnivorousplants.com/CP_Photos/cp_photos_3.htm 

 

 

 

_________Human Uses of Thread-Leaved Sundew and Other Facts_________________

 

                        Most noticeably in Canada, thread-leaved sundew habitats, which are

                        often threatened,are not protected areas. The seeds of the plant are

 

                        commonly dispersed through water, and the life-span is thought to be

                        around fifteen years. Humans covet this plant as a beautiful wildflower,

                        and while other sundew species are known to have remedial herbal qualities,

 

                       thread-leaf does not seem to have such qualities. In 1991,

                        Nova Scotia placed the species on their endangered species list

                        (COSEWIC, 2002).

                        In the U.S., it is not officially at risk at a national level, but individual states do

                        consider it a threatened species. This plant is not common in most regions

                        of the world, (as the map indicates), and could be confused with the

 

                        Drosera filiformis species var. filiformis, which is found less in the southern

                        states. Var. filiformis is also smaller than var. tracyi and requires a winter season to survive on a long-term basis.

 

 

 

                        Var. Filiformis <--------------------->Var. Tracyi

                      For more information on this, check out:                   filformis vs. tracyi

                                                                         http://www.redfernnaturalhistory.com/glistcarnimagegallery1.htm

 

                       Although the thread-leaved sundew does not fulfill any physical human

                       need, as noted, its aesthetic quality, as been long admired by humans.

                       Sundews are often mentioned in art; specifically in writing and poetry.

                       Take a moment to read this poem written by Amy Clampitt (1920-1994).

 

                       The Sun Underfoot Among The Sundews

 

An ingenuity too astonishing to be quite fortuitous is this bog full of sundews, sphagnum- lines and shaped like a teacup. A step down and you're into it; a wilderness swallows you up: ankle-, then knee-, then midriff- to-shoulder-deep in wetfooted understory, an overhead spruce-tamarack horizon hinting you'll never get out of here. But the sun among the sundews, down there, is so bright, an underfoot webwork of carnivorous rubies, a star-swarm thick as the gnats they're set to catch, delectable double-faced cockleburs, each hair-tip a sticky mirror afire with sunlight, a million of them and again a million, each mirror a trap set to unhand believing, that either a First Cause said once, "Let there be sundews," and there were, or they've made their way here unaided other than by that backhand, round- about refusal to assume responsibility known as Natural Selection. But the sun underfoot is so dazzling down there among the sundews, there is so much light in that cup that, looking, you start to fall upward.

 

all sources found below in bibliography 

 

 Want to learn more about this beautiful plant? Check out Part II!

 ________________________________________________________________________________________________________

 

             Habitat

 

            Although a brief description of Drosera filiformis var. tracyi was provided above, this section will offer you 

a more detailed glimpse into the life of the Thread-leaved Sundew, specifically, where it lives. It is a rare plant found

in a few South-eastern U.S. states, including Georgia, Florida, and the gulf coastal areas of Alabama and Mississippi.

It is also found in parts of Canada and South-western Nova Scotia. Here it is only know to grow in five discrete bogs

in Shelburne county. These sites are known under the following names:

1. Barrington Bog

2. Port La Tour Bog

3. West Baccaro Bog

4. Quinns Meadow

5. Villagedale Bog

            The first of the Sundew found in these sites was discovered at Barrington Bog in 1977, and the most recent

discovery of Sundew took place in Villagedale Bog, almost ten years ago. There are other areas in this

part of Nova Scotia that meet the habitat needs of the plant, approximately 20, but no plants have yet been

discovered in these areas. This information has been  gathered  through COSEWIC, the Committee on the Status of

Endangered Wildlife In Canada. Findings in Nova Scotia offer a more detailed glimpse into the life of this species of

Sundew, these are summed up in a COSEWIC Assessment  document. Page 5 offers a clear map of distribution,

note the differences between this map and the map provided above, which only shows U.S. distribution.

            To learn more about Sundews in general, and where they are located all over the world, check out this     

cool animated map:                 Sundew species all over the world

 

            This plant grows in bogs, and prefers sandy, moist soils. It is commonly found in pine woods, and

grows closely together. The plant is found in temperate coniferous forests, source and good images

 

 

Drosera filiformis var. tracyi's Division, (under Kingdom) is Magnoliophyta, its part of the Magnoliopsida class,

its under the Caryophyllales order, and is part of the Droseraceae family. source                    

 

            Threats

 

            In general, one of the main known threats against the species is peat mining. Sediment increase of

minterals in bogs alter the make-up of these bogs, and create environments which do not suppor Drosera

species. Much is not known specially on Drosera filiformis var. tracyi. I had trouble finding detailed information

on threats to the species I studied. However, any disturbance that affects the hydrologic flow of bogs is a

potential threat to the species of Drosera. They require a stable and saturated environment to aquire higher

levels of nutrients. Activities such a road building, logging, and other human disturbance caused by

development can put Drosera species at risk. Thus, all threats are directly related to humans. I have yet to

come across a common widepsread threat created by other wildlife. As mentioned earlier, many Drosera

species are considered endangered or threatened throughout their range (at least in the U.S.), and

share similar traits. Check out this site to compare Drosera rotundifolia to Drosera filiformis var. tracyi.

What similarites do you see?

 

__________________________________________________________________________________________________

 

 

                                                                                   Bibliography

 

 

Poem : http://www.poemhunter.com/poem/the-sun-underfoot-among-the-sundews/

 

                          Map1 : plants.usda.gov/java/profile?symbol=DRFI  | USDA.gov | NRCS

 

                          Map 2 :  virtuelle.qefil.de/~chrusty/droserakeyeng.htm quick link

 

 

                          Video: http://www.youtube.com

                                     2008 YouTube, LLC

                                                                                        Books

 

                        Wexler, Jerome: Sundew Stranglers, Plants That Eat Insects. Dutton Children’s

                                      Books, 1995.

 

                       

 

                                                                   Online Articles and Documents

 

 

                        COSEWIC : COSEWIC Assessment and Update Status Report on the Thread-leaved

                                     Sundew Drosera filiformis in Canada ENDANGERED. 2001, COSEWIC

                                     (Committee on the Status of Endangered Wildlife in Canada).

                                     Minister of Public Works and Government Services Canada, 2002. quick link 

 

 

                        Gibson, Thomas C.: Differential Escape of Insects from Carnivorous Plant Traps.

                                     American Naturalist. The University of Notre Dame, 1991.

                                     http://www.jstor.org.  quick link.

                              

 

                         International Carnivorous Plant Society: www.carnivorousplants.org.

                                     Maintained by John Brittnacher quick link . 

 

 

                        Rice, Barry. The Carnivorous Plant FAQ, v. 11.5. (courtesy of) The International

                                    Carnivorous Plant Society: www.sarracenia.com/faq/faq5265.htm.

                                    January, 2007. quick link 

 

 

 

                        Unknown Author. Drosera filiformis var. tracyi "Thread Leaf Sundew", or "Dewthreads"

                                    www.geocities.com/pitcherplants/Dtracyi.html quick link

 

 

 

 

 

                         Wikipedia: http://en.wikipedia.org/wiki/Drosera_filiformis. January, 2008.

 

 

 

 

                         Wolf, Evan; Gage, Edward; & Cooper, David J. : Drosera rotundifolia L. (round leaf sundew):

                                      A Technical Conservation Assessment. Prepared for the USDA Forest Service,

                                      Rocky Mountain Region, Species Conservation Project. June, 2006. quick link 

 

 

 

 

                          Zenner, Michael : Carnivorous Plants. http://www.rdrop.com/users/mvz/plants.htm#drosera

                                     ICPS CP Database, February 5, 1999.