Plants That Only Exist on One Mountain — And Why That’s Dangerous

The Secret World of Mountain Endemics

Endemic species, in ecology, any species or other taxon whose geographic range or distribution is confined to a single given area. Although the species may inhabit a very small area, such as a single lake, or its range may extend across an entire continent, it is considered endemic if it is not found anywhere else in the world. When we talk about single-mountain endemics, we're discussing the ultimate botanical specialists – plants that have evolved to thrive in one specific location and absolutely nowhere else. These aren't just rare plants; they're evolutionary marvels that have adapted to incredibly specific conditions. For instance, an endemic species might be found only in a particular mountain range at a certain elevation zone and nowhere else, or only in a particular lake, a single river or a small island. Often, endemic species are confined to a certain area because they are highly adapted to a particular niche. Think of them as nature's ultimate homebodies, but their inability to relocate could be their downfall. The specificity that makes them unique also makes them incredibly vulnerable to any changes in their environment.

The San Francisco Peaks: A Case Study in Danger

The San Francisco Peaks ragwort (Packera franciscana) is an endemic plant species that occurs only in upper tree-line and alpine habitats of the San Francisco Peaks in northern Arizona. P. franciscana is federally listed as threatened due to its narrow geographic distribution, apparent specificity to volcanic talus habitat, and concerns over recreational impacts and climate change. This single-mountain endemic perfectly illustrates the precarious situation these plants face. Due to limited area for upslope migration, a warming climate could lead to local extinction of this rare species. The ragwort has nowhere to go when conditions change – it's literally trapped on its mountain. Plants are a vital component of biodiversity but are facing a high rate of extinction worldwide. In the United States, 57 percent of federally listed species are plants. The San Francisco Peaks ragwort represents countless other single-mountain species facing similar fates worldwide, each one a unique evolutionary story that could be lost forever.

Table Mountain's Botanical Treasures Under Threat

The Devil's Heath gets its name from Devil's Peak, since it only occurs from here to the lower saddle where it joins up with Table Mountain. This is suggested in the subspecies name "diabolis" – Latin for "devil". Unfortunately, it is believed that its population is slowly decreasing and so it has been Red Listed as Critically Endangered (CR). It is found within such a small area that a single major event such as an intense wildfire could potentially harm the population beyond recovery – that is if the plants have not had enough time to reach full maturity since the last wildfire. Table Mountain in South Africa hosts numerous endemic species, each one existing in an incredibly narrow range. As with most Fynbos species, the Sticky Diamondeyes flower heavily relies on wildfires to stimulate new regrowth. Since parts of Table Mountain have gone for many years without fire, this species is unfortunately very rare. It is found only on Table Mountain and nowhere else. These plants have evolved with the mountain's unique fire cycles and specific microclimates, making them sitting ducks for environmental changes. Their survival depends on maintaining delicate ecological balances that can be disrupted by human activities or climate shifts.

Hawaii's Island Endemics: Paradise Lost?

The Hawaiian Islands are home to amazing array of unique plants. Today it is estimated that there are approximately 1,400 vascular plant taxa (including species, subspecies, and varieties) native to the State of Hawai'i, and nearly 90 percent of these are found nowhere else in the world. Hawaii represents one of the most dramatic examples of endemic evolution, but it's also becoming a cautionary tale. Today Hawaiʻi is often referred to as the "Endangered Species Capital of the World." More than 100 plant taxa have already gone extinct, and over 200 are considered to have 50 or fewer individuals remaining in the wild. Officially, 366 of the Hawaiian plant taxa are listed as Endangered or Threatened by Federal and State governments, and an additional 48 species are Proposed as Endangered. Many of these species are found on single mountains or even single volcanic peaks. This endemic plant is found only on the Mokuleia side of the Waianae Mountains on the island of Oahu, usually on rocky cliffs either exposed to the sun or as an understory plant. The isolation that created this incredible diversity is now working against these plants as threats multiply faster than conservation efforts can keep pace.

The Climate Change Avalanche

Climate change is expected to threaten endemic plants in the Alps. Among mountain species, endemic plants are expected to be more affected by climate change due to their small niche-breadths, small population sizes, low genetic diversity, specific habitat requirements and low dispersal ability. In particular, in the Alps, endemic plants growing at high elevation are more sensitive to climate change than endemics growing at low elevation. Climate change isn't just another threat – it's an existential crisis for single-mountain endemics. Climate change poses unprecedented threats to ecosystems worldwide, and mountainous regions with rare ecosystems, unique landscapes, a large number of endemic species, and enormous plant biodiversity are highly sensitive to the effects of climate change. Early spring and late autumn events are major phenological changes observed in plants in response to climate change, and such changes mainly disturb the interaction between plants and their pollinators, thereby affecting the fitness and survival of both species. These plants are experiencing a perfect storm of environmental pressures. Snow cover duration has declined in nearly all regions, especially at lower elevations, on average by five days per decade. On average across Western North America, the European Alps and High Mountain Asia, temperatures are warming by 0.54 degrees Fahrenheit per decade. For a plant that has spent thousands of years adapting to specific temperature and moisture conditions, these rapid changes are catastrophic.

The Uphill Battle: When There's Nowhere to Go

A vertical ascent of around 500 meters could compensate for a 3° C rise in average temperature, but because available land area decreases with increasing altitude, species with large habitat area requirements may become extinct. In any case, associations of species will be squeezed into decreasing areas as they ascend. Some alpine species would simply "wink out" under a global warming scenario, as there would be no higher elevation habitat nearby to which they could migrate. This is perhaps the most chilling aspect of single-mountain endemism – when conditions become unsuitable, these plants have literally nowhere to go. Mountains are experiencing extensive changes in land-use and climate and increasing levels of biological invasion, with temperature increasing faster than global averages at high elevations in many mountain ranges. Such rapid changes in temperature are expected to result in extinctions of cold-adapted plant species in mountains, coupled with a dramatic turnover in alpine plant communities. It's like being trapped in a burning building where the only exit is blocked. Moreover, endemics restricted to the tops of not snow-cladded mountains and endemics limited by lithological (e.g. massive limestone) and/or pedological barriers are supposed to be most threatened since they may hardly shift their distributional range tracking new suitable areas. The very specialization that allowed these species to thrive in their unique mountain environments has become their death sentence.

Invasive Species: The Uninvited Guests

Invasive plant species can directly impact the activity, productivity, and survival of native biota. They have superior potential to compete for space and resources and a more efficient capacity to utilize resources than the native species. Thus, they have a major influence on resources (e.g., nutrients) and space in new habitats, as well as modify ecological processes, thereby outcompete native species and degrade the habitats of native biota in the ecosystems. In brief, invasive plant species displace native plant species from their original habitats, degrade ecosystems, have a negative impact on human health, and homogenize the world's biological systems, and cause global biodiversity loss. Single-mountain endemics are sitting ducks for invasive species. The Peninsula Conebush is also threatened by invasive alien plant species which compete with it for crucial resources like water and space. These native plants evolved in isolation without the competitive pressures that shaped plants in more connected ecosystems. When aggressive introduced species arrive, the endemics simply can't compete. In addition to landslides and other types of land degradation, invasive species have made it difficult for this plant to grow. One of these species is the rose-apple tree (Syzgium jambos), which was brought to the island as a wood fuel source. This tree not only grows tall to crowd out other species, but it also spreads its roots laterally and stops other seeds from taking hold. It's an ecological David versus Goliath story, but David doesn't have a slingshot.

The Pollinator Crisis: When Partners Disappear

The effects ripple through the ecosystem as global warming disrupts plants and seed production, which, in turn, means less food for small mammals and birds. Graceful yellow glacier lilies are blooming 17 days earlier than they did in the 1970s, but migrating hummingbirds that depend on the flower nectar aren't keeping up. By the time they arrive, many of the plants have withered away, and if current trends continue, in two decades the hummingbirds will miss the first flowers entirely. Ecosystems could collapse as global warming continues to decouple complex ecological relationships, showing why global warming is a threat to biodiversity. Many single-mountain endemics depend on specific pollinators that have co-evolved with them over millennia. Populations of many plants (e.g., Schiedea spp.) are small and fragmented, facing threats such as dwindling genetic variation and reduced outcrossing as pollinator populations decline or disappear. When climate change disrupts these delicate timing relationships, both the plants and their pollinators suffer. The situation becomes even more precarious when you consider that these endemic plants often have such small populations that losing even a few individuals to poor pollination can push the entire species toward extinction. It's like watching a perfectly choreographed dance fall apart when the music changes tempo.

Habitat Destruction: The Human Factor

Although extinctions occur naturally, the current rate of plant and animal extinctions is much higher than the natural or historical rates. Habitat loss is the primary cause of higher extinction rates. Other causes include habitat changes, over-exploitation of wildlife for commercial purposes, the introduction of harmful nonnative species, pollution, and the spread of diseases. Human activities pose perhaps the most immediate threat to single-mountain endemics. Also known as the baseball plant, Euphorbia obesa is found only in the Great Karoo region of South Africa. Unsustainable harvesting by collectors and plant exporters almost resulted in the plant becoming extinct. As a result, national and international legislation have been enacted to protect the remaining populations. Development, mining, tourism, and even well-meaning hikers can destroy fragile mountain ecosystems. As trees and other vegetation are removed from mountainous landscapes, soil quality, fertility and stability begin to deteriorate as the nutrients provided by decaying plant matter cease to be replenished, and the root systems disintegrate. This can also result in landslides, soil erosion and further vegetation and nutrient loss that gradually denudes the landscape, making it difficult for the wildlife that resides in these areas to survive. For a plant that exists in only a few square kilometers, even small-scale disturbances can be catastrophic. Every cleared patch, every new trail, every development project chips away at their already minuscule habitat.

The Genetic Bottleneck: Inbreeding and Vulnerability

Rarity itself leads to an increased risk of endangerment and extinction, because rare plants with few and small populations are less able to recover from random events that wipe out individuals or entire populations. This kind of risk is called "stochastic risk". For example, the small size of the only known population of showy stickseed, Hackelia venusta, is a major barrier to its recovery. The small number of individuals (roughly 600 plants) remaining in the sole population located in Tumwater Canyon makes H. venusta vulnerable to extinction due to random events such as slope failure (mass wasting or surface erosion) or drought. A single random environmental event could extirpate a substantial portion or all of the remaining individuals of this species, leading to extinction. Small populations create a vicious cycle of vulnerability. With few individuals to choose from, these plants often resort to inbreeding, which reduces genetic diversity and makes them even more susceptible to diseases and environmental changes. It is often the case that species with a small geographic range have a low local abundance and are patchily distributed. Such characteristics make a species more susceptible to environmental change or disturbance and increase the potential for extinction. It's like a small town where everyone is related – problems that affect one individual quickly spread through the entire population. The genetic toolkit that might help them adapt to changing conditions gets smaller and smaller with each generation.

Fire Cycles: When Natural Processes Go Wrong

Warmer and longer summers dry out vegetation and increase the threat of wildfires in western mountain forests, where the fire season has lengthened by at least a month since 1979. The growing wildfire risk is just part of an accelerating cycle of global warming impacts in the world's mountain regions, according to a new Intergovernmental Panel on Climate Change report that includes a section focused on mountains for the first time in more than 20 years. Many mountain plants have evolved with specific fire cycles, depending on periodic burns for reproduction and ecosystem renewal. Worsleya procera is threatened by commercial collecting and a high frequency of wildfires. Naturally rare, it is threatened by poaching and wildfires. In 2008, a major inferno wiped out part of the wild amaryllis populations. But climate change is disrupting these natural fire patterns, creating either too much fire or too little. Looming threats like climate change and wildfire pose increasing risks. Climate models predict that 5% of the flora of Hawai'i will have no remaining habitat by 2100. Some species need fire to germinate their seeds, while others can't survive the increasingly intense blazes. It's a delicate balance that took millennia to establish and just decades to destroy.

The Collector's Curse: Loving Plants to Death

While Euphorbia obesa remains endangered in its native habitat, it has become very common in cultivation. By growing large numbers of this plant, nurseries and botanical gardens have been working to ensure that specimens being traded and sold among plant collectors are not obtained from the wild, thus protecting it for posterity. The rarity of single-mountain endemics makes them incredibly desirable to collectors, creating a perverse incentive for their destruction. In 1976, American botanist Dennis Breedlove collected several specimens. By the time the golden fuchsia was described in 1987, its only known location had been ploughed over for agriculture. Presumed Extinct in the Wild, all golden fuchsia plants in cultivation are thought to be descended from Breedlove's seeds. Plant collectors, both legal and illegal, can decimate small populations in their quest for rare specimens. The yellow fatu (Abutilon pitcairnense), a plant with pale yellow flowers, is endemic to Pitcairn Island. Though it was discovered on the island in 1898, sightings were not common. It was believed to be extinct prior to