| 
  • If you are citizen of an European Union member nation, you may not use this service unless you are at least 16 years old.

  • Stop wasting time looking for files and revisions. Connect your Gmail, DriveDropbox, and Slack accounts and in less than 2 minutes, Dokkio will automatically organize all your file attachments. Learn more and claim your free account.

View
 

Snyder, K - Digitalis purpurea

Page history last edited by PBworks 12 years, 5 months ago

 Scientific Name: Digitalis purpurea

Common Name: Common Foxglove1

Digitalis purpurea photographed by Philip Jägenstedt in Stora Hultrum, Sweden, on the 10th of July 2005. Image from wikipedia.org1.

 

 I chose Digitalis purpurea because it is used as a common heart medicine yet is highly poisonous when ingested in its wild form.  It is also a beautiful plant to see growing alongside the road, adding color to ditches and disturbed areas.

 Location:  Digitalis purpurea (Foxglove) is native to most of western Europe (see map 1 below) but is also widely distributed across the United States (see map 2 below) where it is considered to be weedy or in California and Oregon invasive2.  Foxglove thrives in cool, moist climates with acidic soils3.  According to the World Wildlife Fund’s interactive website4 the main biome region containing these ideal conditions is temperate broadleaf and mixed forests across the Palearctic but can also be found in Mediterranean forests, woodlands, and scrub as well as temperate coniferous forests. 

                Life form:  Digitalis purpurea is an herbaceous biennial5 with the leaves forming a spiral rosette at ground level the first year and the flowering stem growing one to two meters tall in the second year1.  While hummingbirds flock to flowering foxglove, honeybees tend to be the primary pollinators3.  Flowering occurs between June and July of that second year5.  Inside each of the multiple purple tubular flowers, which appear like bells or fingers of gloves on the flowering stem, are capsules which contain numerous minute seeds which are wind dispersed1. 

 

Illustration of Digitalis purpurea from Köhler's Medizinal-Pflanzen published in 1887. Image from wikipedia.org1.

 

Uses/ Interesting Facts:  The two main toxins which can prove fatal if directly ingested from a wild specimen of Foxglove, digitoxin and digoxin, can also be purified in the lab to create a powerful heart medicine which strengthens and helps regulate a person’s heartbeat.  However, even in medicinal form, care must be taken not to overdose as it will be fatal1.  A steroid found in the leaves and flowers of Digitalis purpurea, digoxigenin, can also be used in molecular biology to isolate and bind to DNA and RNA in lab experiments1.  Besides being used for medicinal purposes and in laboratory experiments, Foxglove is also considered to be quite beautiful and is therefore also planted in many gardens.  Shady borders and woodland gardens offer Foxglove a place to showcase its tall inflorescences which tend to tower over smaller cultivated plants3.  While purple or lavender are the most common flower colors, Digitalis purpurea also blooms in pink, white, cream, or yellow3. 

 

Picture of inside one of the flowers of Digitalis purpurea. Image from wikipedia.org1.  Photographed by Kurt Stueber in 2003.

 

 

 

 

 Map 1. Native range of Digitalis purpurea in western Europe shown. Map created using adobe photoshop and the websites of about.com6 and the Ecological Database of the British Isles7. 

 

Map 2. Distribution of Digitalis purpurea in the United States. Image from the USDA plants database2.

 


 

 Biome and Habitat Information for Digitalis purpurea

 

              The primary biome and native range for Digitalis purpurea, also known as Foxglove, is the temperate broadleaf and mixed forests biome4.  It can however also be found in Mediterranean forests, woodlands, and scrub as well as temperate coniferous forests4.

             To understand the temperate broadleaf and mixed forests biome, one must first define the meaning of temperate.  Temperate simply means the geographical location of the place in question lies between the tropical and polar circle latitudes and has relatively mild seasonal changes with unpredictable weather8.   The temperate broadleaf and mixed forests biome itself encompasses regions on the North American, South American, European, and Australian continents9.  I will be focusing on the western European region since this is the native habitat for Foxglove.

             The climate in a western European temperate broadleaf and mixed forest consists of moderate annual temperatures ranging 5.5 and 15.6 degrees Celsius with distinctive warm and cool seasonal periods9.  Annual rainfall is between 24 and 60 inches with a dry season occurring in the summer9.

              Temperate broadleaf and mixed forest structure is easily broken down into four layers: the canopy, subcanopy, shrub layer, and herbaceous layer9.  Composed of mature trees, the canopy is typically dominated by such species as oak, beech, birch, and maple10.  Being more shade tolerant and waiting for an opportunistic opening in the canopy, the subcanopy is made up of smaller mature less dominant trees, saplings and suppressed juveniles.  Woody plants growing lower to the floor comprise the shrub layer.  Closest to the forest floor and typically the most diverse section of the temperate broadleaf and mixed forest is the herbaceous layer or understory9.   This is seeded by grasses, smaller flowers, and spring ephemerals10.  Digitalis purpurea is most commonly found in this layer.  Some researchers tend to include a fifth layer as well called the ground cover layer which consists of lichens, clubmosses, and true mosses11.

            Habitat destruction is a commonality amongst all biomes, and this is certainly true for the temperate broadleaf and mixed forest biome in western Europe as well.  While a widespread extinction during the Pleistocene era eradicated many species of plants, clearing for agriculture took the heaviest toll on the biome in terms of biodiversity loss.  Fragmented remnants of these forests survive due to royals conserving them as royal hunting preserves11.   In terms of species distributions, most dominant species such as the beech, birch, oak, and maple, have widespread ranges across the entire ecoregion.  It’s the understory species which are unable to cross fragmented clusters of forest.  However, there is a high restoration potential according to the World Wildlife Fund10.  Plants are not the only life forms affected by the habitat fragmentation though.  Breeding songbirds are vulnerable to parasitism or elevated nest predation.  Larger natural landscapes are needed for bigger carnivores to subside in these forests10.  All of these factor into keeping the temperate broadleaf and mixed forest biome healthy and thriving. 

 

 

 

 


 

 

 References:

 

 1. Wikipedia: Digitalis purpurea. [Internet]. USA: Wikipedia Foundation Inc.; c2008 [cited 2008 Feb 19]. Available from http://en.wikipedia.org/wiki/Common_Foxglove

 

 2. Plants profile: Digitalis purpurea. [Internet]. Washington, DC: US Department of Agriculture.; c2008 [cited 2008 Feb 19]. Available from http://plants.usda.gov/java/profile?symbol=DIPU

 

 3. Floridata: Digitalis purpurea. [Internet]. Tallahassee, Florida: Floridata.; c1996 [cited 2008 Feb 19]. Available from http://www.floridata.com/ref/D/digi_pur.cfm

 

 4. Wild World: Terrestrial ecoregions of the world. [Internet]. Washington DC: World Wildlife Fund.; c2008 [cited 2008 Feb 19]. Available from http://www.nationalgeographic.com/wildworld/terrestrial.html?detail=undefined&size=large&id=1&cMinx=-180&cMaxx=180&cMiny=-117.20930232558139&cMaxy=117.20930232558139

 

 5. The Burke Museum of Natural History and Culture: Digitalis purpurea. [Internet]. Seattle, WA: University of Washington.; c2006 [cited 2008 Feb 19]. Available from http://biology.burke.washington.edu/herbarium/imagecollection.php?Genus=Digitalis&Species=purpurea

 

 6. About.com: Geography. [Internet]. New York, New York: The New York Times.; c2008 [cited 2008 Feb 19]. Available from http://z.about.com/d/geography/1/0/1/L/europe.jpg

 

 7. Ecological Database of the British Isles. [Internet]. United Kingdom: Peat H, Fitter A, Ford, H [cited 2008 Feb 19]. Available from http://www.ecoflora.co.uk/search_eudistrib.php?plant_no=1540170020

 

 8. Temperate. [Internet]. USA: Wikipedia Foundation Inc.; c2008 [cited 2008 Mar 6]. Available from http://en.wikipedia.org/wiki/Temperate

 

  9. Temperate broadleaf and mixed forests. [Internet]. USA: Wikipedia Foundation Inc.; c2008 [cited 2008 Mar 6]. Available from http://en.wikipedia.org/wiki/Temperate_broadleaf_and_mixed_forests

 

10. Temperate broadleaf and mixed forest ecoregions. [Internet]. Washington DC: World Wildlife Fund.; c2006 [cited 2008 Mar 6]. Available from http://www.panda.org/about_wwf/where_we_work/ecoregions/about/habitat_types/selecting_terrestrial_ecoregions/habitat04.cfm

 

11. About.com: Temperate broadleaf deciduous forest. [Internet]. New York, New York: The New York Times Company.; c1996 [cited 2008 Mar 6]. Available from http://biology.about.com/gi/dynamic/offsite.htm?zi=1/XJ&sdn=biology&cdn=education&tm=4&f=00&tt=2&bt=0&bts=0&zu=http%3A//www.radford.edu/%7Eswoodwar/CLASSES/GEOG235/biomes/tbdf/tbdf.html

 

 

Webpage created by Katherine Snyder. Last Updated March 6, 2008.

 

Comments (0)

You don't have permission to comment on this page.