Some Halophytic Plants: Takhini Salt Flats, Yukon, Canada

In this note, I provide an overview of some salt-loving and salt-tolerant plants that grow on the Takhini Salt Flats, Yukon, Canada. The plants I focus on are called halophytic plants. They not only tolerate, but they thrive on saline, alkaline substrates.

This written note is a companion to two YouTube videos that describe:

a) some geological factors that led to the creation of the Takhini Salt Flats and associated alkaline lakes; and

b) a speculation about the presence of a spectacular magenta-coloured purple sulphur bacteria that grows in one of the salt lakes on the Takhini Salt Flat.

The Takhini Salt Flats are located west north-west of Whitehorse, Yukon, in the Ibex Valley (Photo 1).

This is not a comprehensive overview of all plants that grow on, and in the area of, the Takhini Salt Flats. It is a synthesis of only a few the halophytic and other plants that grow on the Takhini Salt Flats (Photo 2). Plants that survive on the Takhini Salt Flats must have the ability to tolerate saline conditions, drought, low-nitrogen soils, and cold/freezing conditions.

At the end of the note, in the epilogue, I speculate about the fate of the Takhini Salt Flats in the face of a changing climate.

Halophyte plants

As a basis to understand the unusual salt-loving and salt-tolerant plants on the Takhini Salt Flats, let’s review what botanists call a halophyte plant. Botanists classify salt-loving and salt-tolerant plants as halophytes or halophytic plants. Halophytes are:

• salt resistant or salt-tolerant plants that naturally survive thrive and complete their life cycles in soils or waters that contain high concentrations of salt;

• are able to survive in saline conditions by taking advantage of less saline moisture within the soil profile and by adapting to seasonal variability in salinity by altering germination, growth and reproduction cycles;

• characterized by genetic, biochemical, and other mechanisms that enable them to survive in salt-rich environments, but those mechanisms are beyond my knowledge and are too complex to discuss in this note;

• are considered to be an obligate species, that are restricted to, and dependent upon, saline habitats in order to reproduce; and

• are found in high salinity wetlands along ocean coasts, in dry to semi-dry inland areas, and in high salinity salt flats associated with inland lakes where evaporation exceeds lake recharge.

Halophyte plants are not common. Only about 2% of the world’s flora are halophyte plants.

Special Climate of Ibex Valley:

The Takhini Salt flats do not occur along an ocean coastal region; rather, the Takhini Salt Flats lie within the inland Ibex Valley, Yukon. So, what is so unusual about the Ibex Valley that led to the development of the salt flats and alkaline lakes? Simply, the summer is warm and evaporation of shallow thermokarst lakes causes the precipitation of the salt.

Thermokarst lakes (Photo 3) formed in the Ibex Valley at the end of the last ice age. Those thermokarst lakes are the foundation of the Takhini Salt Flats. Salts that occur on the Takhini Salt Flats originally were dissolved by water from local geological materials like rocks and sediments. The sediments were deposited on the bottom of proglacial Lake Champagne, which formed towards the end of the last ice age. The dissolved salts entered surface water and groundwater, filled the shallow thermokarst lakes, and/or percolated down to aquifers. Because the climate of the Ibex Valley results in warm summer, with limited precipitation, the lake water and soil moisture evaporate quickly, leaving the dissolved salt behind. This climate and resulting evaporation lead to the development of saline soils, salt lakes, and brackish groundwater.

More details are provided in my YouTube video entitled “Salt of the Earth: Takhini Salt Flats, Yukon, Canada”.

Why Are Halophytic Plants Of Interest?

Halophytic plants are different and new to many of us. That alone is interesting. Also, with changing climate, some geographic areas are experiencing a trend toward increasing salinity in agricultural soils. That increasing soil salinity affects the types of crops that farmers can grow. Understanding how halophyte plants tolerate salty soil may help farmers continue to adapt to this salinity trend.

Salt type, Takhini Salt Flats:

The salt type exposed on the Takhini Salt Flats is not table salt, which is sodium chloride (Photo 4).

 The salt on the Takhini Salt Flats is reported to consist of hydrated sodium (Na) sulphate (SO4) in the form of two minerals: a) mirabilite (Na2SO4·10H2O); and b) thenardite (Na2SO4) (Photo 5 and 6). These salts are not unique to the Takhini Salt Flats. Mirabilite and thenardite are also common around the margins of salt lakes located across the prairies of Alberta, Saskatchewan and parts of Manitoba.

Simple Habitat Classification:

The halophytic plants I recognized and photographed on the Takhini Salt Flats are summarized in the context of a very simple habitat classification (Photo 7 - the image is located at the end of the document because of the odd image size). The simple habitat classification considers the physical characteristics of the substrate in which the plants grow as well as key plants that grow in that physical setting. The habitat and plant community zonation I suggest is based on subjective observation, proximity to standing water, apparent type and dryness of the substrate, and distribution of a very few plant species, all of which are qualitative measures. My simple habitat classification consists of:

1. lake;

2. lake edge;

3. salt flat; and

4. meadow grassland.

Like many classifications, the habitat zones are not separated by hard walls. Rather, the habitat zones are gradational into each other, as is the distribution of supported plant communities.

I have no doubt that that a botanical expert would see more refined habitat and plant community distribution patterns. For example, a preliminary analysis of plant communities on Yukon salt flats was carried out in 2005 by Pippa Seccombe-Hett and Jennifer Line (unpublished report made available to me by Bruce Bennett, Coordinator, Yukon Conservation Data Centre at Environment Yukon). Although preliminary, their observations are very useful, influenced my simpler habitat classification, and helped guide what I looked for in the field and in my photos.

I have no doubt that that a botanical expert would see more refined distribution of habitats based on substrate and plant community distribution patterns, but my simple habitat classification is a place to start to look for a relationship between plant distribution and geological substrate.

Incomplete List Of Takhini Salt Flat Flora:

I have Included an incomplete list of plant species that I photographed on the Takhini Salt Flats (Photo 7, located at end of this note). More comprehensive lists are available from Bruce Bennett, Coordinator, Yukon Conservation Data Centre at Environment Yukon.

I am not a trained botanist and I have not provided description of plant features or key identification criteria because there are many credible and reliable online resources that achieve that goal. My plant species identifications are based on corrections or confirmations provided by experts on iNaturalist, where I have posted all my observations.

Zone 1: Lake

This habitat is self explanatory. It consists of standing water in a shallow thermokarst lake (Photo 3 and 6). The light colour of the lake bottom suggests that sodium sulphate salts accumulate on the lake bottom during the summer, when lake evaporation takes place. I did not spend a lot of time looking at this habitat, but it does support an unusual aquatic species.

Example halophytic plants in zone 1 - lake:

1) Spiral ditchgrass (Ruppia cirrhosa) (Photo 8), is also known informally as Spiral Tasselweed, western ditchgrass and widgeongrass. It is a native, circumpolar, perennial aquatic plant that is considered to be a halophyte.

• Habitat: Its global habitat includes shallow, saline, alkaline ponds and lakes, marshes, ponds, and sloughs.

• Conservation status: In Yukon, it is Critically Imperiled (S1).

• Distribution: In Canada, it is known from western and central areas. On the Takhini salt flats, I came across this plant only once, where it was washed up on the shore of an alkaline lake (Photo 8).

 2) Baltic rush (Juncus balticus) (Photo 9), is also informally known as wire rush and wiregrass. It is a native, perennial plant. It is considered to be a halophytic plant.

• Habitat: Its habitat includes salt marshes and alkaline wetlands. It is also known to occur along heavily-salted roadways in parts of North America. It prefers full sun, wet to moist conditions (including shallow water), and sandy soil. It is very winter-hardy.

• Conservation status: In Yukon, this species is considered to be secure (S5).

• Distribution: On the Takhini salt flats, I saw Juncus balticus standing in shallow water of an alkaline lake and on moist, water saturated salt flats and salt marshes close to alkaline thermokarst lakes.

Zone 2: Lake Edge:

The lake edge habitat (Photo 10) occurs as a wet apron immediately adjacent to the edge of the thermokarst lakes. It appears to represent seasonally (vernally) flooded to wet ground. The white-coloured substrate indicates the abundance of salt precipitates. Although I did not systematically examine all lake margins, grains of mineral soil were not obvious suggesting that the amount of salt precipitated dominated the substrate. The salt precipitate appeared to consist of a soft layer. Where the salt layer was drier, it is crusty. Locally, the salt precipitate contains polygonal cracks suggesting the salt precipitate is drying and desiccation cracks are forming (Photo 11).

The lake edge zone is not densely vegetated by diverse species. Rather, in many areas, the lake edge appeared to be only sparsely vegetated, if at all (Photo 11).

Three plants are very diagnostic of the lake edge habitat zone: a)  Red glasswort / Boreal Glasswort [Salicornia rubra (Salicornia borealis)]; b) Saltwater Cress (Eutrema salsugineum); and c) Pursh's seepweed / Horned Seablite (Suaeda calceoliformis).

Example halophytic plants in zone 2 - lake edge:

1) Red glasswort (Salicornia rubra / Salicornia borealis), also known informally as boreal saltwort, red saltwort, red samphire, red swampfire, and Arctic glasswort and Boreal Glasswort, is the most distinctive lake edge habitat species (Photo 12). It is an annual, succulent, halophyte plant, and is reported to be one of the most salt-tolerant plants of North America. In addition to being salt tolerant, this species tolerates alkaline calcareous soils.

I note in the literature there is discussion about this species classification. VASCAN and Flora of North America (FNA) include S. borealis as a synonym of S. rubra. However, FNA states that “Populations of S. rubra from Hudson Bay, growing above mean high water in saltmarshes and estuaries in the vicinity of Churchill, Manitoba, have been described as a distinct species, S. borealis, but they are now known from several localities in N. Ontario and Yukon. They are on average smaller in all their parts than typical S. rubra, but they fall within the lower limits of the range of variation for that species. These populations possess one apparently unique feature in that many of the plants branch at the cotyledonary node, a characteristic not known from other North American populations of Salicornia”. These differences between S. borealis and S. rubra (size and branching) are clearly important and may be grounds to treat S. borealis as a distinct species. I am not qualified to assess this taxonomic argument. Therefore, I have arbitrarily defaulted to VASCAN, where S. borealis belongs to Salicornia rubra and considers Salicornia borealis to be a synonym. This link on iNaturalist illustrates a practical illustration this taxonomic discussion.

In my view, Red glasswort (Salicornia rubra / Salicornia borealis) is the iconic and most distinctive plant growing on the Takhini Salt Flat because its red carpet growth is so obvious. The early vegetative growth is green in colour (Photo 13), but it turns a red colour later in the growing season.

• Habitat: in proximity to ocean shores, it occurs in salt marshes, on tidal flats, shores, and estuaries. Inland, as on the Takhini Salt Flats, it around the edges of alkaline lakes and on the salt flats.

• Conservation status: In Yukon, it is ranked as Imperiled (S2).

• Distribution: It is circumboreal in distribution. In Canada, it is known from a small area along Hudson Bay shore of Manitoba and perhaps adjacent Ontario, as well as in Yukon. On the Takhini salt flats, it is very common along the edges of the thermokarst salt lakes and on moist salt flats. I also saw it in isolated depressions, ranging in diameter from less than a metre to several metres without standing water.

2) Saltwater Cress (Eutrema salsugineum) (Photo 14): Arabidopsis salsuginea  is a synonym and it is also informally known as mouse-ear cress and saltlick mustard. It is a halophytic species. Note that my confidence in the identification of this plant is low, so I include it only as something to look for should you visit the Takhini salt flats.

• Habitat: It is not associated with ocean habitats, meaning this is a non-marine halophytic species. It tolerates extreme salinity. It also tolerates cold. Its preferred habitat is alkaline flats and edges of saline ponds.

• Conservation status: In Yukon, this species is considered to be imperiled (S2).

• Distribution: This species is thought to have originated in central Asia. It migrated to northern China and then to North America in the last 20,000 years. In North America, it occurs in Arctic Canada, through the Rocky Mountains to British Columbia, Montana and Colorado. There is a disjunct population in northeastern Mexico. On the Takhini salt flats, I saw Eutrema salsugineum growing with red glasswort (Salicornia rubra / Salicornia borealis) at the edges of lakes and on salt flats in moist meadow grassland areas.

3) Pursh's seepweed / Horned Seablite (Suaeda calceoliformis) (Photo 15): is also informally known as horned seablite, horned sea-blite, American seablite, pahuteweed, paiuteweed, plains sea-blite, and western sea-blite and Pursh seepweed and horned seablite. It is a native, annual halophyte found in North America. It grows in areas of high soil salinity and alkalinity. Its waxy, fleshy leaves are distinctive. Early in the growing season, the plants are green in colour, but often turn dark red or become spotted with dark red colour later in the season (Photo 15), like red glasswort (Salicornia rubra / Salicornia borealis).

• Habitat: Its habitat consists of saline and alkaline soils on wet to mesic prairies, prairie swales, playas, salt flats, beaches and marshes and has even been reported growing on salted roadsides. In proximity to the ocean, it occurs in brackish or salt marshes and flats, coastal sea beaches that are intertidal, subtidal or open ocean.

• Conservation status: In Yukon, it is ranked as Vulnerable (S3).

• Distribution: It is reported to be widespread across Canada, in places where the right habitat exists, such as playas, salt flats, and coastal regions. In eastern North America it occurs on beaches, in marshes and other wetlands. It can occur along the edges of roads that are salted in the winter. On the Takhini salt flats, I saw this species growing at the edge of lakes (zone 2; Photo 16) and on open, sparsely vegetated salt flats (zone 3).

Zone 3: Salt Flat

The salt flat habitat starts close to the edge of the lake and extends well away from the lake edge, occupying areas that appear to have been an historic lake bottom or lake edge (Photo 17). The salt flats are located at a slightly higher elevation compared to the present-day lake surface. The salt flat habitat (zone 3) appears to be subject to periodic flooding. The salt deposit ranges from a moist mucky deposit to a dry crust when moving farther away from the lake edge. There is a gradational transition between the lake edge habitat and the salt flat habitat. It is reasonable to lump the two habitats into one habitat continuum.

Closer to the lake edge, the salt flat zone is sparsely vegetated. Farther away from the lake edge, on the slightly higher ground, the salt flat is gradational into more intensely vegetated salt flats that resemble a meadow grassland on drier land.

Just as there is a gradual transition between the lake edge habitat and the salt flat habitat, there are transitions between the plants observed in the lake edge and salt flat habitats. The more distinctive plant species in the salt flat habitat include: a) foxtail barley (Hordeum jubatum); b) common arrowgrass (Triglochin maritima); c) seaside buttercup (Halerpestes cymbalaria); d) sea milkwort (Lysimachia maritima); and e) Nuttall's alkaligrass (Puccinellia nuttalliana). Some of the species present in this zone, like Hordeum jubatum and Triglochin maritima, also occur up to the lake edge habitat, showing their tolerance for a range of soil moisture and salinity conditions.

Example halophytic and other plants in zone 3 - salt flat habitat:

1) Seaside buttercup (Halerpestes cymbalaria) (Photo 18): is also known informally as alkali buttercup, seashore buttercup, seaside crowfoot, and shore buttercup. It is a native perennial herb. It is not considered to be an halophytic plant.

• Habitat: It is found on moist to wet saline or alkaline shorelines, tide flats, ditches, muddy clearings, marshes and meadows, montane and steppe zones.

• Conservation status: In Yukon, this species is classified as Apparently Secure (S4).

• Distribution: It is It is a circumpolar plant that occurs in much of Eurasia and parts of North and South America. On the Takhini salt flats, I saw this species growing on moist to dry salt flat habitat (zone 3) and on the moist meadow grassland habitat (zone 4) (Photo 19).

2) Sea Milkwort (Lysimachia maritima) (Photo 20): it was previously called Glaux maritima. It is also known informally as sea milkweed and black saltwort and saltwort. It is a low growing, succulent, perennial, halophyte herb. It tolerates high salinity and long periods submerged under water. Like most halophytes, L. maritima has specialized mechanisms to cope with high concentrations of salt in the rooting zone of its habitat, including salt glands on the leaf surfaces that secrete excess salt which would ordinarily injure plant tissue.

• Habitat: It global habitat includes: a) coastal saline habitats, like tidal flats, coastal marshes, and beaches; and b) mesic interior alkaline marshes and wet meadows in lowland, steppe and montane zones on the prairies, parklands, boreal forest, and montane zones. It prefers moist, sparsely vegetated soil in direct sunlight.

• Conservation status: In Yukon, it is ranked as Imperiled (S2).

• Distribution: Lysimachia maritima is circumpolar in distribution in the northern hemisphere and is native to Europe, central Asia and North America, where it is reported to be widespread in the Arctic and temperate North America. On the Takhini salt flats, I saw this species growing on open, moist salt flats, where salt deposits were obvious and on moist saline substrate in the transition to what I call the meadow grassland habitat (Photo 21).

3) Nuttall's alkaligrass (Puccinellia nuttalliana): Disclaimer! My photos (Photo 22) of Nuttall's Alkaligrass are terrible, but they are the best I have. It is a native halophyte perennial bunchgrass. It can be small and clumpy, as it appears to be on parts of the Takhini salt flats, or it can produce erect stems up to a metre in height.

• Habitat: Its habitat includes coastal salt marshes and inland alkali shores where moist saline grasslands occur and where the soil pH is alkaline.

• Conservation status: This species has no status rank in Yukon.

• Distribution: In North America, it occurs from Alaska throughout Canada and it is common in the western and central United States. It occurs in the Arctic, throughout the temperate mountain ranges, the Great Plains, the Great Basin, and along the western coastline of North America down through California. On the Takhini salt flats, I saw Puccinellia nuttalliana on moist to mesic salt flats, often in close spatial association with red glasswort (Salicornia rubra) (Photo 23), but I confess, I should have paid more attention to this species.

4) Seaside arrowgrass (Triglochin maritima) (Photo 24): Triglochin concinna is a synonym of this species. Is also known informally as common arrowgrass, arrowgrass, common bog arrowgrass, shore arrowgrass, and sea arrowgrass. It can be an annual or perennial.

Interestingly, it is a toxic plant due to the presence of cyanide and is poisonous to humans and livestock. Apparently green leaves are more toxic than dried plant material. Also, this species can increase plant diversity in saline wetlands because it creates rings around the plant. The slightly higher elevation of the rings creates a micro habitat that has lower salinity, which results in less stress due to waterlogging. This increases habitat heterogeneity and increases species diversity (Photo 24). I did not observe this feature on the Takhini Salt Flat.

• Habitat: It is found in brackish marshes, freshwater marshes, wet sandy beaches, fens, damp grassland and bogs, and wet open prairie.

• Conservation status: In Yukon, this species is not ranked.

• Distribution: It has a circumboreal distribution in the northern Northern Hemisphere. On the Takhini salt flats, I saw this species growing in the lake edge habitat (zone 2), the salt flat habitat (zone 3; Photo 17), and in the wet meadow grassland habitat (zone 4).

3) Foxtail barley (Hordeum jubatum) (Photo 25): is also known informally as foxtail, squirreltail barley, squirreltail grass, wild barley, bobtail barley, and intermediate barley. It is a native North American halophytic perennial grass that tolerates salty soils, but is capable of growing on a variety of soil types ranging from loamy to clay-rich alkaline soils with pH’s of 6.4 to 9.5.

• Habitat: it occurs in waste places, roadsides, meadows, bare soil. It is adapted to a wide range of moisture regimes from dry to wet.

• Conservation status: In Yukon, this species is ranked as secure (S5).

• Distribution: occurs wild mainly in northern North America and adjacent northeastern Siberia, but it is widespread across North America. On the Takhini salt flats, I saw this species growing in the lake edge habitat (zone 2; Photo 26), salt flat habitat (zone 3), and the moist, saline meadow grassland habitat (zone 4).

Zone 4: Meadow Grassland

This is a variably vegetated habitat. Sometimes the meadow grassland habitat occurs as raised drier land surrounding a thermokarst lake (Photo 27). Other times, the meadow grassland exists a flat, moist to dry land that appears to be more intensely vegetated land having lower salinity (Photo 28).

Salt locally occurs in the substrate, but generally, not as a thick crust. The substrate can be dry to mesic and I saw non-salt mineral grains in the substrate. The colour of the substrate ranges from grey to white to tan. Locally, in transition with the salt flat habitat, I saw black-coloured crust that resemble a manganese crust, but that is speculation (Photo 29).

The meadow grassland habitat is abruptly transitional into forested land (Photo 30).

The meadow grassland habitat presumably represents the exposed sediment that was deposited on the bottom of the proglacial Lake Champagne.

Many different plant species grow on the meadow grassland habitat (Photo 7). Two plant species that are typical of the meadow grassland zone include Loose-flower milkvetch (Astragalus tenellus) and mealy primrose (Primula incana).

Example plants in zone 4 - Meadow:

1) Loose-flower milkvetch (Astragalus tenellus) (Photo 31): is informally known as pulse milk-vetch and looseflower milkvetch. This native species occurs as bushy clumps and prefers alkaline to calcareous soils.

• Habitat: includes mesic to dry grassy prairie slopes, lakeshores, bluffs, sandy and gravelly flats, roadcuts and open forests from the steppe to lower subalpine zones.

• Conservation status: This species ranked as vulnerable (S3) in Yukon.

• Distribution: This species is native to North America where it occurs on the Great Plains. I note there are two observations in northern Ontario, several in the Northwest Territories, western United States, southern British Columbia and southern Yukon. On the Takhini Salt Flats, I saw this species mostly on the drier land (Photo 32) that appeared to be transitional between dry salt flat habitat and the dry meadow grassland habitat that stood higher than the moist and wet soils associated with the salt lakes.

 2) Mealy primrose (Primula incana) (Photo 33): is also informally known as Jones’ Primrose, hoary primrose, and silvery primrose. Is a native perennial, amphiberingia plant. The plant is often heavily farinose, characterized by the presence of a white, mealy powder on its vegetative parts. That is one distinctive identification criterion (Photo 34) that I find invaluable to identify this primrose species.

• Habitat: includes moist to wet saline lakes and meadows and saturated, often calcareous wetlands in prairies, parklands, boreal, and montane zones. Its preferred sites include areas where the water table is stable, associated streams have a fairly constant water flow with little or no spring flooding, and soils remain moist to saturated, but not flooded, throughout the growing season. It also prefers fine-textured alkaline soils, which is typical of the ancient lake sediments of the Ibex Valley.

• Conservation status: In Yukon, this species is ranked as vulnerable (S3).

• Distribution: On the Takhini salt flats, I saw this species growing on moist meadow grassland habitat.

Epilogue: Threat Of Climate Change

In this note, I presented a synthesis of observations describing some of the plant diversity on the Takhini Salt Flats, Yukon, Canada. I reiterate, my list of plant species (Photo 7) is incomplete and my habitat classification is simplistic. If interested in the plant species observed on the Takhini Salt Flats, you should contact Bruce Bennett, Coordinator, Yukon Conservation Data Centre at Environment Yukon) for a current and comprehensive plant species list.

But, there is a specter in the air. Climate is an important factor influencing plant diversity and distributions. Within a climatic area, substrate geology is also an extremely important factor that influences plant diversity. As a geologist, I am fascinated by those plant-substrate relationships.

The story at the Takhini Salt Flats is fascinating. The Takhini Salt Flats is one excellent example where geological processes and climate strongly influence plant species diversity. Geological processes during, and at the end of, the last ice age created a large pro-glacial lake in the Ibex Valley called Lake Champagne. Sediments that accumulated on the bottom of pro-glacial Lake Champagne and melting soil permafrost conspired together to create thermokarst lakes. Groundwater and surface water, which dissolved salt constituents from the local rocks and sediments, filled the shallow thermokarst lakes. The local climate, consisting of warm dry summers, ensured that lake recharge rate lagged behind the lake evaporation rate. Each year, the high evaporation rate increases the lake salinity, which causes precipitation of sodium sulphate salts, and created and sustains the alkaline lakes and salt flats. That is a wonderful illustration how climate and geological processes create an environment that supports many rare and vulnerable plants on the Takhini Salt Flats. In my opinion, the Takhini Salt Flats is very special area and should be elevated to a protected status, given the number of “at-risk” plant species it supports.

BUT, the Takhini Salt Flats faces a very serious existential risk - that of climate change. If climate change increases precipitation in the region or cooling of the summer season, the delicate balance between lake water evaporation and lake water recharge rate from local precipitation may also change. That may discourage precipitation of the salts if lake water evaporation rate does NOT exceed lake water recharge rate. Under those conditions, sodium sulphate salts will NOT precipitate and existing salts may dissolve away. That would arrest the creation of the salt flats and destroy the unique environment needed to support the rare halophytic plant species that are specially adapted to live on the saline substrate. Climate change is a potential existential threat to the Takhini Salt Flats.

Note of Thanks

In 2019, during my second visit to the Takhini Salt Flats, I was joined by Yukon resident Jozien Keijzer. Her knowledge of the area and the flora and our discussions before, during and after, gave me a much deeper understanding of the flora-geology-climate-substrate relationships represented on the Takhini Salt Flats.

Bruce Bennett, Coordinator, Yukon Conservation Data Centre at Environment Yukon, has also been generous with his knowledge about the Takhini Salt Flats and the local flora. His corrections and confirmations of my identifications posted on iNaturalist have been invaluable. Bruce also linked me with other experts whose guidance was extremely helpful.

Jeff Bond, Manager Surficial Geology, Yukon Geological Survey, was extremely helpful by pointing me to references that set a geological context for the Ibex Valley - a framework for the Takhini Salt Flats.

I extend my thanks and appreciation to Jozien, Bruce and Jeff, although the errors of my simplistic approach remain mine.

April 16/22; rev April 19/22