Digitalis obscura

Classification System: APG IV

Superregnum: Eukaryota
Regnum: Plantae
Cladus: Angiosperms
Cladus: Eudicots
Cladus: Core eudicots
Cladus: Asterids
Cladus: Lamiids
Ordo: Lamiales

Familia: Plantaginaceae
Tribus: Digitalideae
Genus: Digitalis
Sectio: D. sect. Frutescentes
Species: Digitalis obscura
Subspecies: D. o. subsp. laciniata – D. o. subsp. obscura
Name

Digitalis obscura L., Sp. Pl. ed. 2: 867 (1763).

Protologue locality: "Habitat in Hispania."
Lectotypus: Herb. Linn. No. 775.9 (LINN), designated by Sutton in Jarvis (ed.), Order out of Chaos: 480 (2007)

Distribution
Native distribution areas:

Continental: Europe
Regional: Southwestern Europe
Spain.
Continental: Africa
Regional: Northern Africa
Morocco.

References: Brummitt, R.K. 2001. TDWG – World Geographical Scheme for Recording Plant Distributions, 2nd Edition
References
Primary references

Linnaeus, C. 1763. Species Plantarum, ed. 2, Tomus II: 867. Reference page.

Additional references

Jarvis, C.E. 2007. Order out of Chaos: Linnaean Plant Names and their Types. London: Linnean Society of London in association with the Natural History Museum, ISBN 978-0-9506207-7-0, p. 460. Online. Reference page.

Links

Hassler, M. 2020. Digitalis obscura. World Plants: Synonymic Checklists of the Vascular Plants of the World In: Roskovh, Y., Abucay, L., Orrell, T., Nicolson, D., Bailly, N., Kirk, P., Bourgoin, T., DeWalt, R.E., Decock, W., De Wever, A., Nieukerken, E. van, Zarucchi, J. & Penev, L., eds. 2020. Species 2000 & ITIS Catalogue of Life. Published online. Accessed: 2020 June 20. Reference page.
Govaerts, R. et al. 2020. Digitalis obscura in Kew Science Plants of the World online. The Board of Trustees of the Royal Botanic Gardens, Kew. Published online. Accessed: 2020 June 20. Reference page.
International Plant Names Index. 2020. Digitalis obscura. Published online. Accessed: 20 June 2020.
USDA, ARS, Germplasm Resources Information Network. Digitalis obscura in the Germplasm Resources Information Network (GRIN), U.S. Department of Agriculture Agricultural Research Service. Accessed: 28-Oct-07.

Vernacular names
čeština: Náprstník temný
suomi: Hämysormustinkukka

Digitalis obscura, commonly called willow-leaved foxglove or dusty foxglove[1] or spanish rusty foxglove,[2] is a flowering plant native to regions in Spain and Africa. It is also grown as an ornamental flower. This foxglove is a woody perennial plant belonging to the family Plantaginaceae. Along with the other foxgloves it used to be placed in the figwort family, Scrophulariaceae; however, recent genetic research has moved the genus Digitalis to a larger family. It is similar to many of the foxglove species in its high toxicity and medicinal use as a source for the heart-regulating drug digoxin. Its strikingly distinctive amber- to copper-coloured flowers give the species its name and help distinguish it from other members of the genus.

Distribution

Digitalis obscura is native to eastern to southern Spain and northern Africa, [3] where it is found growing in dry, open woods and often on limestone.[4]

Digitalis obscura subsp. laciniata is found in the mountains of Málaga province Spain and northern Morocco.[5] It has serrate or deeply toothed leaf margins in contrast to the smooth margins of the species.
artist depiction of Digitalis obscura
Description

Digitalis obscura is a shrub or herbaceous perennial growing from a woody base, reaching 1 to 3.9 feet (0.30 to 1.19 m) tall.[6] The stems are smooth and erect. The long leaves are basal and form in a rosette fashion growing outward closer to the ground. Smaller leaves grow alternately along the stem. The thick, glossy leaves are lanceolate in shape, with acute tips. The leaves have a blue-green color and a leathery texture that gives them a shine.[7] A mature plant spreads over the ground about 0.75–1.5 feet.[3]
Flowers

The many flowers of the plant are large and tubular, opening into a funnel shape. They droop from the point of attachment to the stem, occurring in clusters on the same side of the floral axis. The flowers are approximately 1.5 inches (3.8 cm) long and have an appearance of dropping bells or snipped-off fingers as the common name of the genus, foxglove, suggests. This foxglove is distinguished by its rusty dark-orange to green-yellow coloured flowers. Inside the flowers, red venation and spotting can also be seen as well as tiny hairs at the tips. The arrangement of the flowers in respect to the stalk is racemes and the flowers droop downward.[8]
Digitalis obscura flowers close-up
Ecology

It occurs in both the mountains and the lowlands near the coast. It blooms during late spring.[3]
Uses
Horticulture

Digitalis obscura is grown in many non-native areas as an ornamental plant. It naturally grows well in dry climates and in high altitudes and is winter hardy in USDA zones 4 to 8.[8] Unlike many other foxgloves, it is drought-tolerant when it is deeply rooted and established. D. obscura grows in either full or partial sun. It prefers average to well-drained soil with pH levels of 5.8–7.2. It may die if left in wet soil over winter. Once established, it is perennial and grows at a rather moderate to fast pace. It is non-invasive and attracts hummingbirds. It is naturally resistant to deer and rabbits.[3]
Medicinal

Digitalis obscura, like many of the other foxgloves, has been used in medicine as a diuretic and to treat heart conditions. For people suffering from heart disease or other heart-related conditions, it can be used to regulate heart rate. In human folk medicine, D. obscura was used for many purposes, such as treating wounds and toothaches. However, the use of herbal medicinal remedies using Digitalis obscura has lessened to a great degree because of the knowledge of its high toxicity.[9]

In ethnoveterinary medicine, the flowering stems of Digitalis obscura were traditionally used to promote wound healing and treat toothaches in animals. It is one of twenty-three species traditionally used in Granada to treat trauma or poisoning in animals.[10]
Toxicity
Main article: Digoxin toxicity

All parts of Digitalis obscura are poisonous if ingested raw, including the roots and seeds. The most potent parts of the plant are the upper leaves.

All foxgloves are highly toxic if eaten because they contain various cardiac glycosides such as digitoxin, digitalin, digitonin, digitalosmin, gitoxin and gitalonin.[11] During digestion, aglycones and a sugar are released by the breakdown of these glycosides. The aglycones directly affect heart muscles and may slow the heart rate until cardiac arrest occurs.
References

"Digitalis obscura (Dusty Foxglove, Willow Leaf Foxglove) | North Carolina Extension Gardener Plant Toolbox".
"Wild Flowers - Digitalis obscura - the Spanish Rusty Foxglove". 29 July 2016.
"Digitalis obscura". Plant Lust. Retrieved 20 March 2012.
Roger Phillips; Martyn Rix (2002). Perennials: The Definitive Reference with Over 2,500 Photographs. Firefly Books. ISBN 978-1-55209-639-0.
"Digitalis obscura subsp. Laciniata (DIKOL)[Overview]| EPPO Global Database".
James Cullen; Sabina G. Knees; H. Suzanne Cubey; J. M. H. Shaw (11 August 2011). The European Garden Flora Flowering Plants: A Manual for the Identification of Plants Cultivated in Europe, Both Out-of-Doors and Under Glass. Cambridge University Press. pp. 211–. ISBN 978-0-521-76164-2.
"Digitalis obscura". Learn 2 Grow. Retrieved 20 March 2012.
"Digitalis obscura". Missouri Botanical Garden. Retrieved 30 March 2012.
"Foxgloves". Botanical-Online. Retrieved 2 April 2012.
Benitez, Guillermo; M. Reyes González-Tejero; Joaquín Molero-Mesa (2011). "Knowledge of ethnoveterinary medicine in the Province of Granada, Andalusia, Spain". Journal of Ethnopharmacology. 139 (2): 429–439. doi:10.1016/j.jep.2011.11.029. PMID 22155471. Retrieved 4 April 2012.
M. I. San Andrés; Rafael Jurado Couto; Emilio Ballesteros Moreno (30 November 2000). Toxicologa animal originada por plantas / Animal Toxicology Originated by Plants: Flora silvestre espaola / Spanish Wild Flora. Editorial Complutense. pp. 75–. ISBN 978-84-7491-580-8.