Resurrecting Café Marron

402010371_aad20102df_o.jpg

Back in 1980, a school teacher on the island of Rodrigues sent his students out to look for plants. One of the students brought back a cutting of a shrub that astounded the botanical community. Ramosmania rodriguesii, more commonly known as café marron, was up until that point only known from one botanical description dating back to the 1800's. The shrub, which is a member of the coffee family, was thought to have been extinct due to pressures brought about during the colonization of the island (goats, invasive species, etc.). What the boy brought back was indeed a specimen of café marron but the individual he found turned out to be the only remaining plant on the island.

News of the plant quickly spread. It started to attract a lot of attention, not all of which was good. There is a belief among the locals that the plant is an herbal remedy for hangovers and venereal disease (hence its common name translates to ‘brown coffee’) and because of that, poaching was rampant. Branches and leaves were being hauled off at a rate that was sure to kill this single individual. It was so bad that multiple layers of fencing had to be erected to keep people away. It was clear that more was needed to save this shrub from certain extinction.

Café-marron-flowers-and-leaves.jpg

Cuttings were taken and sent to Kew. After some trial and tribulation, a few of the cuttings successfully rooted. The clones grew and flourished. They even flowered on a regular basis. For a moment it looked like this plant had a chance. Unfortunately, café marron did not seem to want to self-pollinate. It was looking like this species was going to remain a so-called “living dead” representative of a species no longer able to live in the wild. That is until Carlos Magdalena (the man who saved the rarest water lily from extinction) got his hands on the plants.

The key to saving café marron was to somehow bypass its anti-selfing mechanism. Because so little was known about its biology, there was a lot of mystery surrounding its breeding mechanism. Though plenty of flowers were produced, it would appear that the only thing working on the plant were its anthers. They could get viable pollen but none of the stigmas appeared to be receptive. Could it be that the last remaining individual (and all of its subsequent clones) were males?

carlos.JPG

This is where a little creativity and a lot of experience paid off. During some experiments with the flowers, it was discovered that by amputating the top of the stigma and placing pollen directly onto the wound one could coax fertilization ans fruiting. From that initial fruit, seven seeds were produced. These seeds were quickly sent to the propagation lab but unfortunately the seedlings were never able to establish. Still, this was the first indication that there was some hope left for the café marron.

After subsequent attempts at the stigma amputation method ended in failure, it was decided that perhaps something about the growing conditions of the first plant were the missing piece of this puzzle. Indeed, by repeating the same conditions the first individual was exposed to, Carlos and his team were able to coax some changes out of the flowering efforts of some clones. Plants growing in warmer conditions started to produce flowers of a slightly different morphology towards the end of the blooming cycle. After nearly 300 attempts at pollinating these flowers, a handful of fruits were formed!

cm2.JPG

From these fruits, over 100 viable seeds were produced. What’s more, these seeds germinated and the seedlings successfully established. Even more exciting, the seedlings were a healthy mix of both male and female plants. Carlos and his team learned a lot about the biology of this species in the process. Thanks to their dedicated work, we now know that café marron is protandrous meaning its male flowers are produced before female flowers.

However, the story doesn’t end here. Something surprising happened as the seedlings continued to grow. The resulting offspring looked nothing like the adult plant. Whereas the adult plant has round, green leaves, the juveniles were brownish and lance shaped. This was quite a puzzle but not entirely surprising because the immature stage of this shrub was not known to science. Amazingly, as the plants matured they eventually morphed into the adult form. It would appear that there is more to the mystery of this species than botanists ever realized. The question remained, why go through such drastically different life stages?

A young café marron showing its brown, mottled, lance-shaped leaves.

A young café marron showing its brown, mottled, lance-shaped leaves.

The answer has to do with café marron's natural predator, a species of giant tortoise. The tortoises are attracted to the bright green leaves of the adult plant. By growing dull, brown, skinny leaves while it is still at convenient grazing height, the plant makes itself almost invisible to the tortoise. It is not until the plant is out of the range of this armoured herbivore that it morphs into its adult form. Essentially the young plants camouflage themselves from the most prominent herbivore on the island.

Thanks to the efforts of Carlos and his team at Kew, over 1000 seeds have been produced and half of those seeds were sent back to Rodrigues to be used in restoration efforts. As of 2010, 300 of those seed have been germinated, opening up many more opportunities for reintroduction into the wild. Those early trials will set the stage for more restoration efforts in the future. It is rare that we see such an amazing success story when it comes to such an endangered species. We must celebrate these efforts because they remind us to keep trying even if all hope seems to be lost. My hat is off to Carlos and the dedicated team of plant conservationists and growers at Kew.

Photo Credits: [1] [2] [3] [4] [5]

Further Reading: [1] [2]

Meet the Pygmy Clubmoss

Phylloglossum+drummondii+++005.jpg

No, these are not some sort of grass or rush. What you are looking at here is actually a member of the clubmoss family (Lycopodiaceae). Colloquially known as the pygmy clubmoss, this odd little plant is the only species in its genus - Phylloglossum drummondii. Despite its peculiar nature, very little is known about it.

The pygmy clubmoss is native to parts of Australia, Tasmania, and New Zealand but common it is not. From what I can gather, it grows in scattered coastal and lowland sites where regular fires clear the ground of competing vegetation. It is a perennial plant that makes its appearance around July and reaches reproductive size around August through to October.

Reproduction for the pygmy clubmoss is what you would expect from this family. In dividual plants will produce a reproductive stem that is tipped with a cone-like structure. This cone houses the spores, which are dispersed by wind. If a spore lands in a suitable spot, it germinates into a tiny gametophyte. As you can probably imagine, the gametophyte is small and hard to locate. As such, little is known about this part of its life cycle. Like all gametophytes, the end goal of this stage is sexual reproduction. Sperm are released and with any luck will find a female gametophyte and fertilize the ovules within. From the fertilized ovule emerges the sporophytes we see pictured above.

Phylloglossum-drummondii-04.jpg

As dormancy approaches, this strange clubmoss retreats underground where it persists as a tiny tuber-like stem. Though it is rather obscure no matter who you ask, there has been some scientific attention paid to this odd little plant, especially as it relates to its position on the tree of life. Since it was first described, its taxonomic affinity has moved around a bit. Early debates seemed to center around whether it belonged in Lycopodiaceae or its own family, Phylloglossaceae.

image_thumb-663.png

Recent molecular work put this to rest showing that genetically the pygmy clubmoss is most closely related to another genus of clubmoss - Huperzia. This was bolstered by the fact that it shares a lot of features with this group such as spore morphology, phytochemistry, and chromosome number. The biggest difference between these two genera is the development of the pygmy clubmoss tuber, which is unique to this species. However, even this seems to have its roots in Lycopodiaceae.

If you look closely at the development of some lycopods, it becomes apparent that the pygmy clubmoss most closely resembles an early stage of development called the “protocorm.” Protocorms are a tuberous mass of cells that is the embryonic form of clubmosses (as well as orchids). Essentially, the pygmy clubmoss is so similar to the protocorm of some lycopods that some experts actually think of it as a permanent protocorm capable of sexual reproduction. Quite amazing if you ask me.

Phylloglossum drummondii   003.jpg

Sadly, because of its obscurity, many feel this plant may be approaching endangered status. There have been notable declines in population size throughout its range thanks to things like conversion of its habitat to farmland, over-collection for both novelty and scientific purposes, and sequestration of life-giving fires. As mentioned, the pygmy clubmoss needs fire. Without it, natural vegetative succession quickly crowds out these delicate little plants. Hopefully more attention coupled with better land management can save this odd clubmoss from going the way of its Carboniferous relatives.

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

Further Reading: [1] [2] [3] [4] [5] [6]

The Tecate Cypress: A Tree Left Hanging in the Balance

The tecate cypress is a relict. Its tiny geographic distribution encompasses a handful of sights in southern California and northwestern Mexico. It is a holdover from a time when this region was much cooler and wetter than it is today. It owes its survival and persistence to a combination of toxic soils, a proper microclimate, and fires that burn through every 30 to 40 years. However, things are changing for the Tecate cypress and they are changing fast. The fires that once ushered in new life for isolated populations of this tree are now so intense that they may spell disaster.

1024px-Cupressus_forbesii_range_map_1.png

The taxonomy of the Tecate cypress has undergone a few revisions since it was first described. Early work on this species suggested it was simply a variety of Cupressus guadalupensis. Subsequent genetic testing revealed that these two trees were distinct enough to each warrant species status of their own. It was then given the name Cupressus forbesii, which will probably be familiar to most folks who know it well. Work done on the Tecate cypress back in 2012 has seen it moved out of the genus Cupressus and into the genus Hesperocyparis. As far as I am concerned, whether you call it Cupressus forbesii or Hesperocyparis forbesii matters not at this point.

The Tecate cypress is an edaphic endemic meaning it is found growing only on specific soil types in this little corner of the continent. It appears to prefer soils derived from ultramafic rock. The presence of high levels of heavy metals and low levels of important nutrients such and potassium and nitrogen make such soils extremely inhospitable to most plants. As such, the Tecate cypress experiences little competition from its botanical neighbors. It also means that populations of this tree are relatively small and isolated from one another.

The Tecate cypress also relies on fire for reproduction. Its tiny cones are serotinous, meaning they only open and release seeds in response to a specific environmental trigger. In this case, its the heat of a wildfire. Fire frees up the landscape of competition for the tiny Tecate cypress seedlings. After a low intensity fire, literally thousands of Tecate cypress seedlings can germinate. Even if the parent trees burn to a crisp, the next generation is there, ready to take their place.

At least this is how it has happened historically. Much has changed in recent decades and the survival of these isolated Tecate cypress populations hangs in the balance. Fires that once gave life are now taking it. You see, decades of fire suppression have changed that way fire behaves in this system. With so much dry fuel laying around, fires burn at a higher intensity than they have in the past. What's more, fires sweep through much more frequently today than they have in the past thanks to longer and longer droughts.

Taken together, this can spell disaster for small, isolated Tecate cypress populations. Even if thousands of seedlings germinate and begin to grow, the likelihood of another fire sweeping through within a few years is much higher today. Small seedlings are not well suited to cope with such intense wildfires and an entire generation can be killed in a single blaze. This is troubling when you consider the age distributions of most Tecate cypress stands. When you walk into a stand of these trees, you will quickly realize that all are of roughly the same age. This is likely due to the fact that they all germinated at the same time following a previous fire event.

If all reproductive individuals come from the same germination event and wildfires are now killing adults and seedlings alike, then there is serious cause for concern. Additionally, when we lose populations of Tecate cypress, we are losing much more than just the trees. As with any plant, these trees fit into the local ecology no matter how sparse they are on the landscape. At least one species of butterfly, the rare Thorne's hairstreak (Callophrys gryneus thornei), lays its eggs only on the scale-like leaves of the Tecate cypress. Without this tree, their larvae have nothing to feed on.

Thorne's hairstreak ( Callophrys gryneus thornei ), lays its eggs only on the scale-like leaves of the Tecate cypress.

Thorne's hairstreak (Callophrys gryneus thornei), lays its eggs only on the scale-like leaves of the Tecate cypress.

Although things in the wild seem uncertain for the Tecate cypress, there is reason for hope. Its lovely appearance and form coupled with its unique ecology has led to the Tecate cypress being something of a horticultural curiosity in the state of California. Seeds are easy enough to germinate provided you can get them out of the cones and the trees seem to do quite well in cultivation provided competition is kept to a minimum. In fact, specimen trees seem to adapt quite nicely to California's cool, humid coastal climate. Though the future of this wonderful endemic is without a doubt uncertain, hope lies in those who care enough to grow and cultivate this species. Better management practices regarding fire and invasive species, seed collection, and a bit more public awareness may be just what this species needs.

Photo Credits: [1] [2] [3] [4] [5]

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

Saving One of North America's Rarest Shrubs

Arctostaphylos_franciscana_3.jpg

The chance to save a species from certain extinction cannot be wasted. When the opportunity presents itself, I believe it is our duty to do so. Back in 2010, such an opportunity presented itself to the state of California and what follows is a heroic demonstration of the lengths dedicated individuals will go to protect biodiversity. Thought to be extinct for 60 years, the Franciscan manzanita (Arctostaphylos franciscana) has been given a second chance at life on this planet.

California is known the world over for its staggering biodiversity. Thanks to a multitude of factors that include wide variations in soil and climate types, California boasts an amazing variety of plant life. Some of the most Californian of these plants belong to a group of shrubs and trees collectively referred to as 'manzanitas.' These plants are members of the genus Arctostaphylos, which hails from the family Ericaceae, and sport wonderful red bark, small green leaves, and lovely bell-shaped flowers. Of the approximately 105 species, subspecies, and varieties of manzanita known to science, 95 of them can be found growing in California.

It has been suggested that manzanitas as a whole are a relatively recent taxon, having arisen sometime during the Middle Miocene. This fact complicates their taxonomy a bit because such a rapid radiation has led manzanita authorities to recognize a multitude of subspecies and varieties. In California, there are also many endemic species that owe their existence in part to the state's complicated geologic history. Some of these manzanitas are exceedingly rare, having only been found growing in one or a few locations. Sadly, untold species were probably lost as California was settled and human development cleared the land. 

Such was the case for the Franciscan manzanita. Its discovery dates back to the late 1800's. California botanist and manzanita expert, Alice Eastwood, originally collected this plant on serpentine soils around the San Francisco Bay Area. In the years following, the growing human population began putting lots of pressure on the surrounding landscape.

Arctostaphylos_franciscana_-_Regional_Parks_Botanic_Garden,_Berkeley,_CA_-_DSC04529.jpg

Botanists like Eastwood recognized this and went to work doing what they could to save specimens from the onslaught of bulldozers. Luckily, the Franciscan manzanita was one such species. A few individuals were dug up, rooted, and their progeny were distributed to various botanical gardens. By the 1940's, the last known wild population of Franciscan manzanita were torn up and replaced by the unending tide of human expansion into the Bay Area.

It was apparent that the Franciscan manzanita was gone for good. Nothing was left of its original populations outside of botanical gardens. It was officially declared extinct in the wild. Decades went by without much thought for this plant outside of a few botanical circles. All of that changed in 2009.

It was in 2009 when a project began to replace a stretch of roadway called Doyle Drive. It was a massive project and a lot of effort was invested to remove the resident vegetation from the site before work could start in earnest. Native vegetation was salvaged to be used in restoration projects but most of the clearing involved the removal of aggressive roadside trees. A chipper was brought in to turn the trees into wood chips. Thanks to a bit of serendipity, a single area of vegetation bounded on all sides by busy highway was spared from wood chip piles. Apparently the only reason for this was because a patrol car had been parked there during the chipping operation.

Cleared of tall, weedy trees, this small island of vegetation had become visible by road for the first time in decades. That fall, a botanist by the name of Daniel Gluesenkamp was driving by the construction site when he noticed an odd looking shrub growing there. Luckily, he knew enough about manzanitas to know something was different about this shrub. Returning to the site with fellow botanists, Gluesenkamp and others confirmed that this odd shrubby manzanita was in fact the sole surviving wild Franciscan manzanita. Needless to say, this caused a bit of a stir among conservationists.

median arc.JPG

The shrub had obviously been growing in that little island of serpentine soils for quite some time. The surrounding vegetation had effectively concealed its presence from the hustle and bustle of commuters that crisscross this section of on and off ramps every day. Oddly enough, this single plant likely owes its entire existence to the disturbance that created the highway in the first place. Manzanitas lay down a persistent seed bank year after year and those seeds can remain dormant until disturbance, usually fire but in this case road construction, awakens them from their slumber. It is likely that road crews had originally disturbed the serpentine soils just enough that this single Franciscan manzanita was able to germinate and survive.

The rediscovery of the last wild Franciscan manzanita was bitter sweet. On the one hand, a species thought extinct for 60 years had been rediscovered. On the other hand, this single individual was extremely stressed by years of noxious car exhaust and now, the sudden influx of sunlight due to the removal of the trees that once sheltered it. What's more, this small island of vegetation was doomed to destruction due to current highway construction. It quickly became apparent that if this plant had any chance of survival, something drastic had to be done.

Many possible rescue scenarios were considered, from cloning the plant to moving bits of it into botanical gardens. In the end, the most heroic option was decided on - this single Franciscan manzanita was going to be relocated to a managed natural area with a similar soil composition and microclimate.

Moving an established shrub is not easy, especially when that particular individual is already stressed to the max. As such, numerous safeguards were enacted to preserve the genetic legacy of this remaining wild individual just in case it did not survive the ordeal. Stem cuttings were taken so that they could be rooted and cloned in a lab. Rooted branches were cut and taken to greenhouses to be grown up to self-sustaining individuals. Numerous seeds were collected from the surprising amount of ripe fruits present on the shrub that year. Finally, soil containing years of this Franciscan manzanita's seedbank as well as the microbial community associated with the roots, were collected and stored to help in future reintroduction efforts.

A fran rescue.JPG

Finally, the day came when the plant was to be dug up and moved. Trenches were dug around the root mass and a dozen metal pipes were driven into the soil 2 feet below the plant so that the shrub could safely be separated from the soil in which it had been growing all its life. These pipes were then bolted to I-beams and a crane was used to hoist the manzanita up and out of the precarious spot that nurtured it in secret for all those years.

Upon arriving at its new home, experts left nothing to chance. The shrub was monitored daily for the first ten days of its arrival followed by continued weekly visits after that. As anyone that gardens knows, new plantings must be babied a bit before they become established.  For over a year, this single shrub was sheltered from direct sun, pruned of any dead and sickly branches, and carefully weeded to minimize competition. Amazingly, thanks to the coordinated effort of conservationists, the state of California, and road crews, this single individual lives on in the wild.

Of course, one single individual is not enough to save this species from extinction. At current, cuttings, and seeds provide a great starting place for further reintroduction efforts. Similarly, and most importantly, a bit of foresight on the part of a handful of dedicated botanists nearly a century ago means that the presence of several unique genetic lines of this species living in botanical gardens means that at least some genetic variability can be introduced into the restoration efforts of the Franciscan manzanita.

In an ideal world, conservation would never have to start with a single remaining individual. As we all know, however, this is not an ideal world. Still, this story provides us with inspiration and a sense of hope that if we can work together, amazing things can be done to preserve and restore at least some of what has been lost. The Franciscan manzanita is but one species that desperately needs our help an attention. It is a poignant reminder to never give up and to keep working hard on protecting and restoring biodiversity.

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

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

 

Botanical Gardens & Plant Conservation

BG1.JPG

Botanical gardens are among my favorite places in the world. I find them both relaxing and stimulating, offering something for all of our senses. Botanical gardens are valuable for more than just their beauty. They serve a deeper purpose than simply showcasing endless poinsettia varieties or yet another collection of Dale Chihuly pieces (a phenomenon I can't quite wrap my head around). Botanical gardens are vitally important centers of ex situ plant conservation efforts.

Ex situ conservation literally means "off site conservation," when plants are grown within the confines of a botanical garden, often far away from their native habitats. This is an important process in and of its own because housing plants in different locations safeguards them from complete annihilation. Simply put, don't put all your endangered eggs in one basket.

IMG_2395.jpg

I don't think botanical gardens get enough credit for their conservation efforts. Sadly, such endeavors are often overshadowed. That's not to say we don't have a good handle on what is going on. In fact, a study published in August of 2017 looked at the status of ex situ plant conservation efforts around the globe.

The paper outlines a conservative estimate of the diversity of plants found in botanical gardens and highlights areas in desperate need of improvement. Utilizing a dataset compiled by Botanic Gardens Conservation International (BGCI), the team found that the world's botanical gardens contain somewhere around 30% or 105,209 of the 350,699 plant species currently known to science. In total, they estimate humanities various living collections contain representatives from roughly 90% of the known plant families. That is pretty impressive considering the scale of plant diversity on our planet.

Proportions of the world's plants represented in botanical garden collections ( Source )

Proportions of the world's plants represented in botanical garden collections (Source)

Their research didn't stop there either. The team dove deeper into these numbers and found that there are some serious discrepancies in these estimates. For instance (and to my surprise), botanical gardens house more temperate plant species than they do tropical plant species. They estimated that nearly 60% of the world's temperate plant species are being grown in botanical gardens around the world but only 25% of tropical species. This is despite the fact that most of the world's plants are, in fact, tropical.

Similarly, only 5% of botanical garden collections are dedicated to non-vascular plants like mosses and liverworts. This is a shame not only because these plants are quite interesting and beautiful, but they also are descendants of the first plant lineages to make their way onto land. They are vital to understanding plant evolution as well as plant diversity.

As I mentioned above, ex situ conservation efforts are critical in fighting plant extinctions across the globe. With 1/5 of the world's plants at risk of extinction, the authors of the paper were particularly interested in how botanical gardens were doing in this regard. They found that although various institutions are growing nearly half of all the known threatened plant species on this planet, only 10% of their collection space is devoted to these species. It goes without saying that this number needs to improve if we are to stave off further extinctions.

Taken together, this study paints an interesting and informative picture of botanical garden collections on a global scale. They are doing amazing work to protect and showcase plant diversity. However, there is always a need for improvement. More space and effort needs to be made in ex situ plant conservation efforts. More plants, especially little known tropical species, need to be brought into cultivation. More space must be devoted to propagating threatened and endangered species. Finally, more attention must be given to natural plant diversity rather than gaudy cultivars. If you love botanical gardens as much as I do, please support them. As the authors so eloquently summarize, "Without deep sustained public support, the plant conservation movement will struggle."

Further Reading: [1]