Discovering botanical gardens of the Canary Islands
Medicinal trees and shrubs of Gran Canaria and Tenerife
I have never been much of a beach person, and journeys seeking the winter sun are really not my thing. But a once-in-a-lifetime trip to the Canary Islands with a visit to Spain’s largest botanical garden was something not to be missed. Here I describe several of the wonderful gardens that we saw on the islands of Gran Canaria and Tenerife. The pull of the exotic made for an exciting trip, eager to see what we could find, including medicinal trees and shrubs that we only see as exotic imports into the UK.
Where are the Canary Islands?
The Canary Islands make up one of the four archipelagos of Macaronesia in the North Atlantic off the coast of Africa. The other three are the Azores, Madeira and Cape Verde. The Canary Islands (seven main islands and many more smaller ones) are an autonomous community of Spain and home to over 2 million people, not counting the zillions of tourists that seek the warm climate year round. We stayed in the substantial city of Las Palmas which is not to be confused with the island known as La Palma. Las Palmas is the joint capital city with Santa Cruz de Tenerife of the Canary Islands. The city is home to some 400,000 people, and it offers a superb melting pot of culture, food, history, music and people from all over the world.
Climate of the Atlantic Ocean
Effectively there is a varied climate from maritime temperate to Mediterranean to subtropical. Since the Canary Islands are based in the Atlantic Ocean there are occasional windy storms but overall rainfall is low. The islands are generally considered to have a desert climate due to lack of rain, totalling just 135 mm for the whole year. However, there are numerous microclimates as rainfall is unevenly spread. The islands with mountains can be sunny on the south side, wetter to the north. And there is evidence of careful water management with reservoirs in significant numbers collecting water from Atlantic storms. In Gran Canaria the climate is balmy in autumn and winter, in daytime averaging from 16-22 degrees C during December with up to five days rain. The coasts to the north of Gran Canaria and the islands to the west such as La Palma are the greener ones. In contrast the more eastern islands of Lanzarote and Fuerteventura tend to be windswept and arid. Despite the low levels of rainfall, extensive forest cover was once common in the Canary Islands.
Botanical garden of Gran Canaria
The Jardín Botánico Canario Viera y Clavijo lies on the outskirts of the city of Las Palmas. This botanical garden on the island of Gran Canaria is reported to be the largest one in Spain. The botanical garden lies in a ravine with steep slopes and numerous narrow paths. At nearly 27 acres in size, the garden is spread across the side of the Guinigarda ravine. There is an incredible range of plants to be found here, from endemic plants of the Canary Islands to large tropical collections of palm trees and much more. Within the garden you can see a laurel forest ('laurisilva') remnant, this is an ecosystem found in an area of high humidity and stable temperature, characteristic of northern slopes of the islands where trade winds create clouds. The laurel forest originated with Mediterranean forests which are now extinct, and is typically dominated by a variety of laurel tree species and rich in ferns, lichens and mosses. When you see this kind of vegetation it is obvious that the level of water conservation is high as every drop of water is captured, and contributing to an ecologically biodiverse and rich environment. Such ancient forest areas are now heavily conserved and protected, some have also been replanted, they are also found on Madeira.
Discovering species of interest
This visit was an opportunity to see some historic plants that were widely used in Europe centuries ago. I was happy to see Pistacia lentiscus (also lentisk or mastic) which is an evergreen shrub or small tree native to the Mediterranean basin. It grows up to 4 m (13 ft) tall and was long harvested for its aromatic resin. Traditionally the resin of this tree, liquorice-like, was used for bronchial and digestive complaints. The physician John Quincy (1730) in Pharmacopoeia officinalis described the balsamic resin of 'mastich' as
'a resinous Gum of the Lentisc Tree ... to strengthen the Stomach, remove Nauseousness and Flatulencies .. to strengthen the Head and invigorate Nerves... very strengthening to the Reins' (p.150)
Much used for sweets, puddings and liqueurs, the mastic resin is still collected today in parts of Greece.
And I just loved seeing the dragon trees. Voyagers to the Canary Islands in the 15th century obtained dragon's blood as bright red drops from Dracaena draco, a tree-like succulent shrub of the Asparagus family, native to the Canary Islands. The resin is exuded from the wounded trunk or branches. Quincy related this resin to the 'cinnabar of Dioscorides' of classical times and wrote admiringly of its astringency and 'success with Fluxes and Haemorrhages' and use in 'strengthening Plaisters' (p.100). The resin had other uses of note, said to be a secret ingredient of the varnish of violins.
Plant labels and herbal medicine
The Jardín Botánico is a very beautiful garden to walk around. It is dedicated to conservation and management of Canarian flora. There are some map displays and occasional boards with English translation. Some plants are labelled. One area is focused solely on palm trees. Other areas showcase the flora of Macaronesia. A huge fossilised tree lies near the entrance. We saw many related species or versions of familiar plants in the gardens, sometimes e.g. Artemisia thuscula, Asparagus scoparius, Juniperus cedrus, Rhamnus crenulata. Some of these plants were recognisable but often it was only the plant labels that alerted me to medicinal potential. In a bookshop in Las Palmas there proved a lucky find of David Bramwell's Medicinal Plants of the Canary Islands, which details many of the herbs particular to the area and their possible uses. Some are unique to the area and incredibly rare such as the climbing butcher's broom (Semele androgyna), a unique woody climber of the laurel forest. This shade-loving plant has unusual flowers which appear on the edges of leaves. Uses for this plant containing steroidal saponins are described as circulatory problems such as varicose veins - so a reasonable substitute is the more widely found butchers broom (Ruscus aculeatus). Other plants that can be found readily growing on wasteland include the Canary Island sage (Salvia canariensis), rich in essential oils and a powerful antiseptic, and most such plants have similar uses to others in related species.
More about agriculture and biodiversity
Of volcanic origin, the Canary Islands have many mountains and valleys, with fertile soils and high biodiversity. If you visit Gran Canaria then it is worth joining a tour to see some of the extensive agriculture. The island grows bananas, tomatoes, cucumbers and aubergines for the European market. Canarian wines and cheese are becoming better known abroad, particularly goat and sheep cheeses from the north, regularly winning international awards. Previously much sugarcane was grown in plantations, now seeing more aloe vera which is sold for body care and as a health supplement. There are examples of coffee plantations though changes in government funding and support have affected some growers. There are also out of season tropical fruits and flowers. Now much of the area (43%) is protected in parks and nature reserves, and there has been reforestation in parts. Since our visit in December 2022 there have been extensive forest fires, particularly in central and upland parts of the island, some, but not all, due to natural causes. Ongoing management of fire in the past may have included increasing grazing and open pasture with animals grazing. The large Canarian pine (Pinus canariensis) is noted for drought tolerance and fire resistance. Unlike many other conifers, this pine can resprout from the lower stem (epicormically) after a fire has passed.
In Tenerife there is another botanical garden
The Jardín de Aclimatación de la Orotava lies on a more formal and compact site and is in a urban area on the western side of the island of Tenerife near to Puerto de la Cruz. Established way back in eighteenth century by royal order by the King of Spain in 1788, it was founded in 1792. This garden has a very different character to the Jardín Botánico, with cool shaded walkways between trees and borders. It is much smaller at 2 ha but very well-established and everything is clearly labelled. Here it was exciting to see some familiar names in herbal medicine - such as the South American pau d'arco (Tabebuia species), sausage tree (Kigelia africana), and other tropical trees of considerable commercial importance including avocado, breadfruit, coffee, figs, jackfruit and macadamia nut. Some of the trees are venerable and huge specimens. The signage is excellent with every species identified plus information boards about plants of interest. The Jardín de Aclimatación is operated by the Canary Island Institute Agricultural Research as a scientific institution, with exchanges of germplasm worldwide. There is a herbarium with emphasis on Canarian flora, with over 47,000 dried specimens, and involvement in research related to preservation of endemic species. This is important work of botanical gardens and there is more about their educational role worldwide available from Botanic Gardens Conservation International (BGCI).
Botanical gardens in history
Nowadays we think of botanical gardens as educational and scientific institutions with extensive plant collections supporting conservation efforts. But perhaps there is a need to discover more of the cultural and economic history of these botanical gardens and others worldwide. Records show that many were originally established to support the exploitation of new worlds! It can be easy to forget how many botanical gardens originate from European colonial expansion and reflect a dominant interest in valuable and useful plants. There was early interest from the sixteenth century in possible new medicines and there were many attempts to discover how they could be cultivated. Some of the botanic gardens were actively involved in the transfer of plant specimens to other places for economic purposes such as plantations which exploited not only plants but also people. While colonies expanded, some European botanic gardens were involved in attempting to acclimatize plants to grow in other climates, though this was not always successful! This is a growing area of historical research which is to be welcomed because it gives us more accurate understanding of how these gardens developed. I am certainly keen to better understand how botanical gardens were intertwined with economic and social history. If this interests you too then an excellent starting point is the well-referenced online article by Marianne Klemum on 'The botanical garden' published by the Leibniz Institute of European History.
Finally…
Much as I love our UK seasonal climate, the chance to see so many subtropical plants was welcome. Normally my year zips from frosty wet winters to unpredictable spring and then summers mixing sun and rain followed by glorious autumn leaf fall. Our visit to the Canary Islands (we were there December 2022) was no beach holiday, it was so much more as the people made us very welcome, and the plants were an absolute delight! I'll be back!
Information about the gardens
Gran Canaria: Jardín Botánico Canario Viera y Clavijo
Address: Camino del Palmeral 15, Tafira Alta, 35017 Las Palmas de Gran Canaria, Gran Canaria, Canary Islands
Website:
http://www.jardincanario.org/
Admission is free. There are upper and lower entrances with some parking. Buses from Las Palmas travel to the higher entrance, but this involves traversing narrow and steep paths down the hillside. A taxi from central Las Palmas costs around €20-€25. There are toilets but no cafe or shop. There is a restaurant near the higher entrance.
Tenerife: Jardín de Aclimatación de la Orotava
Address: C/ Retama nº 2, 38400 Puerto de la Cruz, Tenerife, Canary Islands
Website: https://www.icia.es/icia/jao/autoguiajao/index_en.html
Buses from Puerto de la Cruz. The garden has paved walkways which are accessible for wheelchairs. Entry costs €3 per person. There are toilets and several cafes opposite the entrance. The online information offers a plan in English, French, German and Spanish.
References
Blais, Hélène. 2022. "Botanical gardens in colonial empires." accessed 7 January 2024. https://ehne.fr/en/node/21589
Bramwell, D. 2004. Medicinal plants of the Canary Islands. Madrid, Spain: Editorial Rueda.
Klemun, M. 2018. "The botanical garden." Leibniz Institute of European History, accessed 7 January 2024. http://www.ieg-ego.eu/klemunm-2015-en
Quincy, John. 1730. Pharmacopoeia officinalis and extemporanea. 8th ed. London: J. Osborn and T. Longman.
Ravazzi C, Mariani M, Criado C, et al. 2020. "The influence of natural fire and cultural practices on island ecosystems: Insights from a 4,800 year record from Gran Canaria, Canary Islands." Journal of Biogeography 48: 276-290. https://doi.org/10.1111/jbi.13995