Digitalis purpurea
1158247
218050388
2008-06-08T22:51:16Z
82.22.181.0
/* Toxicity */
{{Taxobox
| name = ''Digitalis purpurea''
| image = Digitalis-stora_hultrum.sweden-24.jpg
| image_width = 240px
| image_caption = ''Digitalis purpurea'' (Common Foxglove)
| regnum = [[Plantae]]
| divisio = [[Flowering plant|Magnoliophyta]]
| classis = [[Magnoliopsida]]
| ordo = [[Lamiales]]
| familia = [[Plantaginaceae]]
| genus = ''[[Digitalis]]''
| species = '''''D. purpurea'''''
| binomial = ''Digitalis purpurea''
| binomial_authority = [[Carolus Linnaeus|L.]]
}}
'''''Digitalis purpurea''''' ('''Common Foxglove''', '''Purple Foxglove''' or '''Lady's Glove'''), is a [[flowering plant]] in the family Plantaginaceae (formerly treated in the family Scrophulariaceae), native to most of [[Europe]].
It is a [[herbaceous]] [[biennial plant]]. The [[Leaf|leaves]] are spirally arranged, simple, 10-35 cm long and 5-12 cm broad, grey-green, downy, and with a finely toothed margin; they form a tight rosette at ground level in the first year. The flowering stem develops in the second year, growing to 1-2 m tall. The [[flower]]s are arranged in a showy, terminal, elongated cluster, each tubular, pendent, purple (also pink, rose, yellow, or white in selected [[cultivar]]s). They are also spotted inside bottom of the tube. The [[fruit]] is a [[capsule (fruit)|capsule]] which splits open at maturity to release the numerous tiny (0.1-0.2 mm) [[seed]]s. In the UK it flowers from June until September.
There are three [[subspecies]]:
*''Digitalis purpurea'' subsp. ''purpurea'' – most of Europe
*''Digitalis purpurea'' subsp. ''heywoodii'' – Iberia
*''Digitalis purpurea'' subsp. ''mariana'' – Iberia
== Toxicity ==
Due to the presence of the [[cardiac glycoside]] [[digitoxin]], the leaves, flowers and seeds of this plant are all [[poison]]ous to humans and some animals and can be fatal if eaten.
Extracted from the leaves, this same compound, whose clinical use was pioneered as [[digitalis]] by [[William Withering]], is used as a medication for [[heart failure]]. He recognized that it "reduced [[dropsy]]", increased [[urine]] flow and had a powerful effect on the heart. Unlike the purified pharmacological forms, extracts of this plant didn't frequently cause intoxication because they induced nausea and vomiting within minutes of ingestion, preventing the patient from consuming more.
The main toxins in Digitalis are the two chemically similar [[cardiac glycosides]]: [[digitoxin]] and [[digoxin]]. Like other cardiac glycosides, the Digitalis toxins exert their effects by inhibiting the [[ATPase]] activity of a complex of transmembrane proteins that form the [[sodium potassium ATPase]] pump, ([[NaKATPase|Na<sup>+</sup>/K<sup>+</sup>-ATPase]]). Inhibition of the [[NaKATPase|Na<sup>+</sup>/K<sup>+</sup>-ATPase]] in turn causes a rise not only in intracellular Na<sup>+</sup>, but also in calcium, which in turn results in increased force of myocardial muscle contractions. In other words, at precisely the right dosage, Digitalis toxin can cause the heart to beat more strongly. However, [[digitoxin]], [[digoxin]] and several other cardiac glycosides, such as [[ouabain]], are known to have steep dose-response curves, i.e. minute increases in the dosage of these drugs can make the difference between an ineffective dose and a fatal one.
Symptoms of Digitalis poisoning include a low pulse rate, nausea, vomiting, and uncoordinated contractions of different parts of the heart leading to cardiac arrest and finally death.
==Uses==
The plant is sometimes grown in gardens. In suitable conditions it generally seeds itself in partial shade, and can become a minor weed.
Selected forms, either for colour or for dwarf habit, are sold as pot plants.
=== Use in [[Molecular Biology]]: [[Digoxigenin]] ===
[[Digoxigenin]] (DIG) is a steroid found exclusively in the flowers and leaves of the plants ''Digitalis purpurea'' and ''[[Digitalis lanata]]''. It is used as a [[molecular probe]] to detect DNA or RNA. It can easily be attached to nucleotides by chemical modifications. DIG molecules are often linked to [[uridine]] [[nucleotides]]; DIG labeled [[uridine]] (DIG-U) can then be incorporated into [[RNA]] probes via [[in vitro transcription]]. Once [[Nucleic acid hybridization|hybridisation]] occurs ''in situ'', [[RNA]] probes with the incorporated DIG-U can be detected with anti-DIG [[antibodies]] that are conjugated to [[alkaline phosphatase]]. To reveal the hybridised transcripts, [[alkaline phosphatase]] can be reacted with a [[chromogen]] to produce a colour precipitate.
<gallery>
Image:04913 Digitalis purpurea nevit.jpg
Image:Digitalis_purpurea6.jpg
Image:Digitalis-stora_hultrum.sweden-05.jpg
Image:Digitalis-stora_hultrum.sweden-15.jpg
Image:Digitalis-stora_hultrum.sweden-18.jpg
Image:Digitalis Purpurea.jpg
Image:Digitalis_purpurea_alba_01-Juni.jpg
Image:Digitalis-stora_hultrum.sweden-19.jpg
Image:Koeh-053.jpg|19th century illustration
Image:Digitalis purpurea 'Primrose Carousel' Flower Stalk 1200px.jpg
Image:Digitalis purpurea 'Primrose Carousel' Flower Closeup 1200px.jpg|Flower closeup
Image:Digitalis purpurea 'Primrose Carousel' Leaves 1100px.jpg|Leaves
</gallery>
==References==
*[http://rbg-web2.rbge.org.uk/cgi-bin/nph-readbtree.pl/feout?FAMILY_XREF=&GENUS_XREF=Digitalis&SPECIES_XREF=purpurea Flora Europaea: ''Digitalis purpurea'']
*[http://www.ecoflora.co.uk/search_species2.php?plant_no=1540170020 Ecological flora of the British Isles: ''Digitalis purpurea'']
*[http://www.plant-identification.co.uk/skye/scrophulariaceae/digitalis-purpurea.htm Skye Flora: ''Digitalis purpurea'']
* [http://plants.usda.gov/java/profile?symbol=DIPU Purple Foxglove] USDA Invasive Plants of the US
{{Commons|Digitalis purpurea}}
[[Category:Plantaginaceae]]
[[Category:Flora of Europe]]
[[Category:Medicinal plants]]
[[Category:Poisonous plants]]
[[ca:Digital (botànica)]]
[[cs:Náprstník červený]]
[[cy:Ffïon]]
[[de:Roter Fingerhut]]
[[es:Digitalis purpurea]]
[[fr:Digitale pourpre]]
[[gl:Dedaleira]]
[[hsb:Čerwjeny naporst]]
[[it:Digitalis purpurea]]
[[he:אצבעונית ארגמנית]]
[[nl:Vingerhoedskruid]]
[[no:Revebjelle]]
[[nn:Revebjølle]]
[[nrm:Digitalis purpurea]]
[[pl:Naparstnica purpurowa]]
[[pt:Dedaleira]]
[[ro:Degeţelul roşu]]
[[sq:Luletogëza e purpurtë]]
[[sk:Náprstník červený]]
[[fi:Rohtosormustinkukka]]
[[sv:Fingerborgsblomma]]