Can Cultivation Save the Canary Island Lotuses?

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Growing and propagating plants is, in my opinion, one of the most important skills humanity has ever developed. That is one of the reasons why I love gardening so much. Growing a plant allows you to strike up a close relationship with that species, which provides valuable insights into its biology. In today’s human-dominated world, it can also be an important step in preventing the extinction of some plants. Such may be the case for four unique legumes native to the Canary Islands provided it is done properly.

The Canary Islands are home to an impressive collection of plants in the genus Lotus, many of which are endemic. Four of those endemic Lotus species are at serious risk of extinction. Lotus berthelotii, L. eremiticus, L. maculatus, and L. pyranthus are endemic to only a few sites on this archipelago. Based on old records, it would appear that these four were never very common components of the island flora. Despite their rarity in the wild, at least one species, L. berthelotii, has been known to science since it was first described in 1881. The other three were described within the last 40 years after noting differences among plants being grown locally as ornamentals.

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All four species look superficially similar to one another with their thin, silvery leaves and bright red to yellow flowers that do a great impression of a birds beak. The beak analogy seems apt for these flowers as evidence suggests that they are pollinated by birds. In the wild, they exhibit a creeping habit, growing over rocks and down overhangs. It is difficult to assess whether their current distributions truly reflect their ecological needs or if they are populations that are simply hanging on in sites that provide refugia from the myriad threats plaguing their survival.

None of these four Lotus species are doing well in the wild. Habitat destruction, the introduction of large herbivores like goats and cattle, as well as a change in the fire regime have seen alarming declines in their already small populations. Today, L. eremiticus and L. pyranthus are restricted to a handful of sites on the island of La Palma and L. berthelotii and L. maculatus are restricted to the island of Tenerife. In fact, L. berthelotii numbers have declined so dramatically that today it is considered nearly extinct in the wild.

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Contrast this with their numbers in captivity. Whereas cultivation of L. eremiticus and L. pyranthus is largely restricted to island residents, L. berthelotii and L. maculatus and their hybrids can be found in nurseries all over the world. Far more plants exist in captivity than in their natural habitat. This fact has not been lost on conservationists working hard to ensure these plants have a future in the wild. However, simply having plants in captivity does not mean that the Canary Island Lotus are by any means safe.

One of the biggest issues facing any organism whose numbers have declined is that of reduced genetic diversity. Before plants from captivity can be used to augment wild populations, we need to know a thing or two about their genetic makeup. Because these Lotus can readily be rooted from cuttings, it is feared that most of the plants available in the nursery trade are simply clones of only a handful of individuals. Also, because hybrids are common and cross-pollination is always a possibility, conservationists fear that the individual genomes of each species may run the risk of being diluted by other species’ DNA.

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Luckily for the Canary Island Lotus species, a fair amount of work is being done to not only protect the remaining wild plants, but also augment existing as well as establish new populations. To date, many of the remaining plants are found within the borders of protected areas of the island. Also, new areas are being identified as potential places where small populations or individuals may be hanging on, protected all this time by their inaccessibility. At the same time, each species has been seed banked and entered into cultivation programs in a handful of botanical gardens.

Still, one of the best means of ensuring these species can enjoy a continued existence in the wild is by encouraging their cultivation. Though hybrids have historically been popular with the locals, there are enough true species in cultivation that there is still reason for hope. Their ease of cultivation and propagation means that plants growing in peoples’ gardens can escape at least some of the pressures that they face in the wild. If done correctly, ex situ cultivation could offer a safe haven for these unique species until the Canary Islands can deal with the issues facing the remaining wild populations.

Photo Credits: [1] [2] [3] [4]

Further Reading: [1] [2] [3] [4]

The Golden Fuchsia: A Case Study in Why Living Collections Matter

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The golden Fuchsia (Deppea splendens) is a real show stopper. It is impossible to miss this plant when it is in full bloom. Amazingly, if it were not for the actions of one person, this small tree may have disappeared without anyone ever knowing it existed in the first place. The golden Fuchsia is yet another plant that currently exists only in cultivation.

The story of the golden Fuchsia starts in the early 1970’s. During a trek through the mountains of southern Mexico, Dr. Dennis Breedlove, then the curator of botany for the California Academy of Sciences, stumbled across a peculiar looking shrub growing in a steep canyon. It stood out against the backdrop of Mexican oaks, pines, and magnolias. Standing at about 15 to 20 feet tall and adorned with brightly colored, pendulous inflorescences, it was clear that this species was something special indeed.

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A subsequent expedition to Chiapas in the early 1980’s was aimed at collecting seeds of this wonderful plant. It turned out to be relatively easy to germinate and grow, provided it didn’t experience any hard frost events. Plants were distributed among botanical gardens and nurseries and it appeared that the golden Fuchsia was quickly becoming something of a horticultural treasure. Despite all of the attention it was paid, the golden Fuchsia was only properly described in 1987.

Sadly, around the same time that botanists got around to formally naming the plant, tragedy struck. During yet another trip to Chiapas, Dr. Breedlove discovered that the cloud forest that once supported the only known population of golden Fuchsia had been clear cut for farming. Nothing remained but pasture grasses. No other wild populations of the golden Fuchsia have ever been found.

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If it was not for those original seed collections, this plant would have gone completely extinct. It owes its very existence to the botanical gardens and horticulturists that have propagated it over the last 30+ years. All of the plants you will encounter today are descendants of that original collection.

The role of ex situ living collections play in the conservation of species is invaluable. The golden Fuchsia is yet another stark reminder of this. If it were not for people like Dr. Breedlove and all of the others who have dedicated time and space to growing the golden Fuchsia, this species would have only been known as a curious herbarium specimen. The most alarming part about all of this is that as some botanical gardens continue to devalue living collections in favor of cheap landscaping and event hosting, living collections are getting pushed to the side, neglected, or even worse, destroyed. We must remember that living collections are a major piece of the conservation puzzle and their importance only grows as we lose more and more wild spaces to human expansion.

Photo Credits: [1] [2] [3]

Further Reading: [1] [2]