Echium pininana, commonly known as the tree echium, pine echium, giant viper's-bugloss, or tower of jewels,[4][5] is a species of flowering plant in the borage family Boraginaceae. It is endemic to the Canary Islands, where it is restricted to the island of La Palma.[6] Echium pininana is an endangered species,[1] and is listed in Appendix I to, and is therefore protected under, the Convention on the Conservation of European Wildlife and Natural Habitats.[7] The specific epithet pininana is Latin for "small pine",[8] though E. pininana is neither closely related to the pine, nor does it resemble that plant.

Echium pininana
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Clade: Angiosperms
Clade: Eudicots
Clade: Asterids
Order: Boraginales
Family: Boraginaceae
Genus: Echium
Species:
E. pininana
Binomial name
Echium pininana
Echium pininana, Tree Echium.

Description edit

Lifecycle edit

Echium pininana is biennial or triennial,[9][10] meaning each plant lives for only two or three years respectively. It is a monocarpic species;[11] each plant flowers only once before dying.[12]

Morphology edit

In their first year, plants produce a rosette of lanceolate leaves approximately 7 cm (3 in) in length, with silver hairs.[5] Plants also produce a trunk 0.9–2.4 m (3–8 ft) tall in their first year,[13] which is covered with many lanceolate leaves.[14] In their second (or third) year, plants produce a cone-like inflorescence up to 4 m (13 ft) high with a dense mass of leaves and small blue flowers.[15][14] Between April and June, the flower spike can grow 5 cm (2 in) per day.[16] Flowers are funnel-shaped,[17] and each produce up to 1.4 μL of nectar, which is approximately 26% sugar.[18] Flowers at the bottom of the flower spike are first to open, with those at the top opening last.[19] Pollinators such as bees, butterflies, and moths are attracted to the flowers.[9] Following pollination, each flower produces four nutlets.[20] Each plant can produce over 200,000 seeds,[10] which are disbursed short distances by the wind.[20]

Phytochemistry edit

Various pyrrolizidine alkaloids, a class of toxic organic compounds that may cause liver damage,[21] have been isolated from Echium pininana.[22] The plant is toxic to horses.[9]

Phylogeny edit

Echium pininana, E. simplex, and E. wildpretii comprise a monophyletic clade.[23] All three of these Echium species are monocarpic, have a similar habit, similar floral morphology, and produce a dimethylated flavone not detected in other Echium species.[11][23]

Distribution and habitat edit

Echium pininana is endemic to the island of La Palma in the Canary Islands, where it grows in laurel forests.[4] It is endangered due to habitat loss caused by agriculture.[10] Outside La Palma, Echium pininana has been introduced to France, Great Britain, Ireland, New Zealand (both North and South Island), and the United States (north and central coast of California).[3][14][24] It is also in ex situ conservation; in fact, the ex situ conservation population is greater than the wild population.[25] It is conserved in botanical gardens such as Kew Gardens in London, where it has naturalised.[26]

Cultivation edit

Echium pininana is cultivated as a garden ornamental, and has gained the Royal Horticultural Society's Award of Garden Merit.[5][27] It is used as a bedding plant or planted in borders, and grows best in full sun.[13] It is recommended for the southern maritime counties of England, the Channel Islands and the Scilly Isles. There are, however, reports of successful cultivation in the English Midlands[28] and Yorkshire,[29] albeit in favourable locations. Specimens are also grown in Dublin gardens at Howth and in the Irish National Botanic Gardens at Glasnevin. The plant also grows readily in North Wales where it seeds very widely. Although E. pininana is half-hardy in Britain and Ireland, it will self-seed to form clusters of plants, and it is suggested that by natural selection a hardier variety will emerge.[10] The plant is most vulnerable to frosts in its first year. Because of its large leaves when partly grown, it is also very susceptible to wind damage. Hence a sheltered garden position is essential. Echium pininana 'Alba' is a cultivar with white flowers.[30]

Notes edit

  1. ^ Echium pininana Webb & Berthel. is the preferred citation, although this species is also cited as Echium pininana Webb & Bernh., and Echium pininana Webb & Berth..[2]

References edit

  1. ^ a b Santos Guerra, A. & Reyes Betancort, J.A. (2011). "Echium pininana". The IUCN Red List of Threatened Species. 2011. IUCN: e.T165250A5996251. doi:10.2305/IUCN.UK.2011-1.RLTS.T165250A5996251.en. Retrieved 22 May 2018.
  2. ^ Tweddle, John (2004-03-29). "Echium pininana Webb & Berthel". Natural History Museum. The Trustees of The Natural History Museum, London. Archived from the original on 2021-06-24. Retrieved 2021-06-19.
  3. ^ a b "Echium pininana Webb & Berthel". Plants of the World Online. Kew Science. Archived from the original on 2021-01-20. Retrieved 2021-06-19.
  4. ^ a b Wilson, Matthew (4 March 2016). "Rocket plant takes off: how towering Echium pininana has spread". FT.com. Financial Times. Archived from the original on 2019-09-24. Retrieved 2021-06-18.
  5. ^ a b c "RHS Plantfinder - Echium pininata". Retrieved 12 January 2018.
  6. ^ Manuel Arechavaleta, S. Rodríguez, Nieves Zurita, A. García (Hrsg.): Lista de especies silvestres de Canarias. Hongos, plantas y animales terrestres (List of Forest Species of the Canary Islands). 2009. Gobierno de Canarias, p. 151 ISBN 978-84-89729-21-6
  7. ^ "Echium pininana - Webb. & Berth". eunis.eea.europa.eu. European Environment Agency. Archived from the original on 2014-04-22. Retrieved 2021-06-19.
  8. ^ Harrison, Lorraine (2012). RHS Latin for Gardeners. United Kingdom: Mitchell Beazley. ISBN 978-1845337315.
  9. ^ a b c "Echium pininana". BBC Gardeners' World Magazine. Retrieved 2021-06-19.
  10. ^ a b c d "Increase Of Cold Hardiness Of Echium Pininana Through Natural Selection". December 1992. Archived from the original on 27 June 2009. Retrieved 22 May 2018.
  11. ^ a b Al-Shehbaz, Ihsan A. (1991). "The Genera of Boraginaceae in the Southeastern United States". Journal of the Arnold Arboretum. Supplementary Series. 1: 1–169. doi:10.5962/p.315943. ISSN 2472-8659. JSTOR 43782784.
  12. ^ "Definition of monocarpic". Lexico.com. Oxford University Press. 2020. Archived from the original on 2021-06-24. Retrieved 2021-06-18.
  13. ^ a b "Echium pininana 'Blue Steeple'". www.chicagobotanic.org. Chicago Botanic Garden. Archived from the original on 2021-06-24. Retrieved 2021-06-19.
  14. ^ a b c Kelley, Ronald B. (2012). "Echium pininana, in Jepson Flora Project (eds.)". Jepson eFlora. Archived from the original on 2017-08-29. Retrieved 2021-06-19.
  15. ^ Carlquist, Sherwin (1970). "Wood Anatomy of Echium (Boraginaceae)" (PDF). Aliso: A Journal of Systematic and Evolutionary Botany. 7 (2) – via CORE.
  16. ^ Robinson, David (2003). "Plants that changed my life". The Horticulturist. 12 (4): 5–9. ISSN 0964-8992. JSTOR 45142512.
  17. ^ "BBC - Gardening: Plant Finder - Tree echium". www.bbc.co.uk. Retrieved 2021-06-19.
  18. ^ Valido, Alfredo; Dupont, Yoko L.; Olesen, Jens M. (2004). "Bird-Flower Interactions in the Macaronesian Islands". Journal of Biogeography. 31 (12): 1945–1953. doi:10.1111/j.1365-2699.2004.01116.x. hdl:10261/63423. ISSN 0305-0270. JSTOR 3554673. S2CID 35788157.
  19. ^ Woodley, Millie (11 January 2021). "Plant of the month". Fulham Palace. Fulham Palace Trust. Archived from the original on 2021-01-11. Retrieved 2021-06-19.
  20. ^ a b State of Victoria (Agriculture Victoria) (2020-08-18). "Giant Viper's-bugloss (Echium pininana)". vro.agriculture.vic.gov.au. Victoria State Government. Archived from the original on 2019-03-26. Retrieved 2021-06-19.
  21. ^ "Definition of pyrrolizidine alkaloid". Lexico.com. Oxford University Press. 2020. Archived from the original on 2021-06-24. Retrieved 2021-06-19.
  22. ^ Roeder, E.; Liu, K.; Bourauel, T. (1991-01-01). "Pyrrolizidine alkaloids from Echium pininana". Phytochemistry. 30 (9): 3107–3110. doi:10.1016/S0031-9422(00)98263-3. ISSN 0031-9422.
  23. ^ a b Bramwell, David (1973). "Studies in the genus Echium from Macaronesia" (PDF). Monographiae Biologicae Canarienses. 4: 71–82.
  24. ^ "Echium pininana Webb & Berthel". www.gbif.org. Retrieved 2021-06-19.
  25. ^ Maunder, Mike; Higgens, Sarah (1998). "A Survey of Bern Convention Plant Taxa in European Botanic Gardens - initial findings and implications". Botanic Gardens Conservation News. 2 (10): 29–31. ISSN 0965-2582. JSTOR 24753901.
  26. ^ Verdcourt, B. (2009). Verdcourt, B. (ed.). "Additions to the Wild Fauna and Flora of the Royal Botanic Gardens, Kew". Kew Bulletin. 64 (1): 183–194. doi:10.1007/s12225-008-9084-0. ISSN 0075-5974. JSTOR 20649641. S2CID 40246634.
  27. ^ "AGM Plants - Ornamental" (PDF). Royal Horticultural Society. July 2017. p. 35. Retrieved 24 January 2018.
  28. ^ Joe Edwards (2017-06-02). "Is this Cannock plant the tallest in the country?". Express & Star. Retrieved 2021-07-30.
  29. ^ Alan Mather (2020-05-25). "Giant Viper's bugloss, Tree Echium, Pine echium, Echium pininana. East Yorkshire, England, UK, GB. - Image ID: 2C3WKXP". www.alamy.com. Retrieved 2021-07-30.
  30. ^ Fallon, Fionnuala (2021-06-12). "Ten summer flowers to add height and energy to your garden". The Irish Times. Archived from the original on 2021-06-13. Retrieved 2021-06-19.

External links edit