The first month on Cat Ba Island – getting my bearings

My apologies for the long gap between posts, life has been a bit busy.

I recently began a new position in Vietnam, on Cat Ba Island to be specific.  My first impressions are that this is a damp and precipitous landscape.  I have not seen the sun since I arrived in Vietnam on March 4th.  For Cat Ba Island this means a riotous profusion of greenery tempered by the steep terrain and lack of soil.

Where the northern end of the road terminates

Where the northern end of the road terminates

This is a land where Ymir’s bones lie close to the surface, broken and weathered, their calcium leaking back into the waters from which these precipitous cliffs rise.  The geology is the first thing that strikes you here.  The cliffs have been weathered by millions of years of rain, the ever-so-slightly acid rainwater eating into the ancient limestone creating a mature karst landscape.  Like bones, coral, and seashells, limestone is primarily made up of calcium carbonate, which in other forms makes marble and dolomite.  This is probably one of the reasons this is a place where snail diversity is immense, ranging from tiny frilled creatures more akin to limpets to giant land snails, many of which are still unknown to science.  Snails need lots of calcium to make their shells.

Unknown frill terrestrial snail

Unknown frilly terrestrial snail

Land snail shells collected around the office - and a wasp nest

Land snail shells collected around the office – and a wasp nest

The banded limestone found here is a relic of abundant diatom (a type of plankton) skeletons laid down five hundred million yeas ago and subjected to the vagaries of time.  Limestone, while soft to the chisel and hammer, is a remarkably durable stone at the macro-scale, one of the reasons climbers like it, but at a chemical level it is easily weathered.  We are often told that water has a pH of 7, that is it neutral.  Natural rainwater, we then assume, should also have a pH of 7, but it is closer to 5.6 due to the dissolution of carbon dioxide into the water making carbonic acid.  A pH of 5.6 is about as acidic as a cucumber or an onion for comparison.  Of course, other environmental factors can reduce this tremendously, leading to extremely acidic rain.  Rain falling on the limestone erodes small channels in the rock that look like thumbprints in wet clay.

Rainwater erosion on limestone

Rainwater erosion on limestone

Eventually these concentrate water flow, carving small holes in the stone reducing it to a swiss-cheese like structure with an extremely jagged and sharp exposed surface.  These little caves connect into larger caves.  In these protected, damp environments bacteria grow, exuding waste products and creating hydrogen sulfide that mixes with the water and makes a weak sulfuric acid, increasing the chemical weathering.  This cycle persists, eventually leading to enormous caves.

The airflow in these caves evaporates the mineral rich water tricking through the now porous stone and the calcium carbonate re-solidifies into stalagmites, stalactites, soda straws, and any number of strangely beautiful and complex cave structures.

Caves often form in weak portions of the stone and, eventually, gravity takes its toll and the weakened rocks collapse leaving behind steep spires and fields of slowly eroding boulders.

Limestone spi

Limestone spire in the north end of Cat Ba Island

Cat Ba and Ha Long Bay are examples of a drowned karst landscape, a mature karst landscape that has been flooded by rising waters.  What little soil does form is washed down into the many bays, coves, and channels of the region, leaving little for plants to sink roots into.  In the shallow waters of the bays mangroves find nutrients, in abundance.  Here mangroves are near the northern margin of their range, their numbers restricted and the trees short, making low dense forests.

Gray mangroves on the south western side of the island

Gray mangroves (Avicennia marina) on the south western side of the island

As in many places, the mangroves are in trouble here, often cut down to make shrimp farms.  This leads to reduction in local fisheries, increased erosion, and lack of protection from storm surges and tsunamis.  The local government is taking steps to protect what remains and to, potentially, restore some of the previous mangrove forests.  In the rich mud of the mangrove regions there are numerous animals, among them one of my favorites, mudskippers, amphibious fish that hop about in the mud protecting their little territories.

Mudskipper amongst mangrove roots

Mudskipper amongst mangrove roots

On the cliffs however there are few nutrients and plants grow in what cracks and declivities they can find.  As per many islands there are a number of endemic species, here one of the most commonly seen ones is the Ha Long Cycad (Cycas tropophylla), an ancient type of gymnosperm that looks like a cross between a fern and a palm tree.

Ha Long Cycad (Cycas tropophylla), endemic to a 400km square area, globally rare, locally abundant

Ha Long Cycad (Cycas tropophylla), endemic to a 400 square km area, globally rare, locally abundant

The season here is shifting into spring and some of the trees have begun blooming, among them the hoa gạo or Cotton Tree (Bombax ceiba), so named for the kapok-like fibers that are found in the seed pod.

Hoa Gạo (Bombax ceiba), Cotton Tree in English.  The Vietnamese name translates to "Rice Flower"

Hoa Gạo (Bombax ceiba), Cotton Tree in English. The Vietnamese name translates to “Rice Flower”

 

I still have not seen the little primates I came here to work with, they are few in number and they clamber about on the vertical cliffs like, well, monkeys.

Soon though.

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Plant Defenses – myriad strategies

Plants, as you might imagine, devote a great deal of energy to defending themselves from predators.  We humans have a natural bias towards animals, creatures that are like us in that they are mobile and respond to stimulus on a timescale similar to ours.  Plants operate, with a few notable exceptions, on a slower timescale, but this in no way should be taken to imply that they are any less interactive vis-a-vis their surroundings.

Plants react to light and dark, sense gravity, moisture, nutrients, and toxins; some can “feel” other organisms (Venus fly traps for example) or “hear” sounds (sensitive plants).  One thing all organisms must cope with is predators and competitors, and all organisms need defenses against these threats.  Plants are no different in their needs, but they are largely immobile, so some of their defenses tend to take a different form than they do in animals.  Surprisingly, their defenses are not as different from animal defenses as one might expect.  I would break plant defenses into three broad categories: chemical, physical, and co-optive.

Chemical defenses often involve toxins of one sort or another or pungent aromas.  Some of these we assiduously avoid, such as certain members of the Sumac (Anacardiaceae) family like poison oak (Toxicodendron diversilobum) and poison ivy (Toxicodendron radicans) due to the allergen urushiol found in the sap.  Other plants using chemical defenses we consume with great relish, many of our foods and spices, for example, derive their strong flavors from the defenses the plant manufactures to deter herbivorous predators.  Mints (Lamiaceae), rosemary, cinnamon, peppers, and onions are good example of common foods we consume that utilize strong chemical defenses.  Other chemical defenses we find recreational and/or medical uses for; ephedrine from plants in the Ephedra family, THC from Cannibus, and cocaine refined from alkaloids found in the coca family (Erythroxylaceae) all have enormous economies reliant on them.

Coca cultivation in Bolivia near Coroico

Coca cultivation in Bolivia near Coroico

Chemical defenses are enormously interesting and extremely sophisticated, but they are largely hidden from us until we are affected by them.  This is part of the reason why eating unfamiliar plants is so dangerous, there are few good ways to determine if a plant is edible upon first encounter.

Physical defenses are the most obvious to us, especially when they come in the form of thorns and barbs, but those defenses barely scratch the surface of the types of physical defenses plants can employ.

An impressive but unsubtle defense - Ceiba speciosa in the Bolivian Amazon

An impressive but unsubtle defense – Ceiba speciosa in the Bolivian Amazon

Sharp pokey bits may defend plants against larger herbivores and chemicals help to protect them from insects or pathogens, but other plants themselves can be, if not predatory, at least detrimental to large trees.  Lianas and other climbing plants, epiphytes, parasitic plants, and even other large trees may need to be defended against.

Strangler fig (Ficus spp.) overwhelming a palm tree's defenses - Bolivia

Strangler fig (Ficus spp.) overwhelming a palm tree’s defenses – Bolivia

The photo above I find particular interesting as the palm tree being overwhelmed by the strangler fig usually has an effective counter to this sort of attack.  Palm trees and tree ferns both allow their old fronds to droop as they age, sheathing the trunk and providing a structure for climbing plants to adhere to.  Eventually these canny plants shed their dead fronds, and with them the uninvited plant guests that have taken up residence.  Many trees employ a similar strategy, eucalyptus and madrone have smooth bark that regularly sloughs off in strips.  The combination of smoothness and shedding makes it difficult for other plants to gain purchase.

Strangler fig is a generic term for a wide variety of tropical fig trees sharing a similar life strategy.  These are the “matapalo” or killer trees.  Rather than growing from the ground and climbing up these trees co-opt animals to carry their tiny seeds through the canopy.  A small portion of these seeds wind up in a place like the crotch of a branch or a broken limb where organic material has built up.  The young fig sends dangling roots down from the canopy in search of nutrients, eventually reaching the ground and transitioning from a vine-like life style to a more tree-like life style.  More and more ground-seeking tendrils make their way downwards, eventually ringing the host tree and strangling it.  As this happens the strangler fig uses the original host as a scaffold and sends its own canopy high enough to overshadow the unfortunate host.  The palm tree in the photo above was underneath a tree the strangler fig took root in and had the misfortune to be attacked from above rather than from below.

Color is an oft overlooked plant defense, the role of which is still being debated.  I don’t mean fruit color, that is blatant advertising and animal bribery.  The color and pattern of the leaves and trunk of plants may serve as defense against predators.

The most familiar example of this is variegation in leaves, that is the white or colored mottling seen most often in ornamental plants, but also occasionally found in the wild.

Variegated hibiscus leaf. Source

Color mottling in leaves is often a symptom of nutrient deficiency, insect predation, viral infection, or genetic chimerism (expression of more than one genetic sequence in a single organism).  In most of the above cases this indicates poor health in the plant, and a plant in poor health makes for an unappetizing meal.  Some plants seem to capitalize on this and mimic the effects of various types of poor health (eg. false leaf damage and variegation) to trick predators into avoiding what appears to a be an un-nutritious meal(1)(2).  Bark color, whether natural or as a result of mutualistic lichen growth may be a predator deterrent as well, as lighter colors may make predators more visible to other predators higher up on the food chain.

Before moving on to animal co-option I should mention one other strategy employed by some plants.  Outgrow your predators.  In this case a plant allocates few resources to defense and focuses on growth and/or reproduction.  Balsa trees follow this strategy, they grow astoundingly rapidly and produce copious numbers of seeds.  They are not long lived and have few toxins, as a result they are subject to immense amounts of predation from a wide range of species.  Some of these, such as tapirs, they avoid by growing out of their reach.  Others are more problematic.  I saw a 30 foot tall young balsa tree completely stripped of leaves by leaf cutter ants in less than two days.

Basla saplings - Bolivia

Basla saplings – Bolivia

The most interesting of the plant defenses, to my mind, is animal co-option for defense.  Ants are probably the animal most often co-opted by plants.  We don’t often think of plants as being the ones to manipulate animals, but that is more a reflection of our animal bias than of the true nature of things.  Plants are highly manipulative, in their slow manner.  Like many effective manipulators, they accomplish their ends via bribes (and in a few cases by outright lies – orchids tricking bees into trying to mate with the flowers is a classic example of vegetative duplicity).  Ants are employed as guards by a great number of plant species.

When I first arrived in the Amazon I recall thinking to myself, “Cool, I hope I get to see some of the ant/plant mutualism.”  The first plant I looked at closely was a common understory shrub in the widespread and diverse Melastomataceae family.

Melastomataceae with ant sheltering nodes at the base of the leaves - Peru

Melastomataceae with ant sheltering nodes at the base of the leaves – Peru

At the base of each leaf there was a hollow, swollen node with two small openings on the underside.  Tiny ants occupied these nodes and would rush out to defend the plant when it was bumped.  This is a surprisingly effective defense against herbivores of all sorts, insect and mammalian.  All through the Amazon (and elsewhere in the world) ants and plants have banded together.  I found arboreal ferns with hollow rootballs harboring and colonies, tall cecropia and smoke trees (“palo diablo” – devil trees) with hollow trunks harboring vast numbers of fierce and painful fire ants, and evocative single species plant stands called Chullachaqui gardens.

According to legend the Chullachaqui is a forest guardian spirit that keeps small monoculture garden plots scattered here and there in the forest.  One should be wary entering these areas, ask permission first, and be careful not to damage any of the plants the Chullachaqui grows.  This is good advice as the Chullachaqui gardens are home to a species of ant that lives underground and kills all the plants growing on the surface except for one species.  Animals that interlope are attacked also attacked and the bite and sting of the ant is painful as it contains formic acid.

One of the neatest ant-plant interactions comes in the form of hanging “ant gardens”.

Ant garden in Peru with Monstera spp.

Ant garden in Peru with Monstera spp.

The dense cluster of plants in the above photo is growing from an arboreal ant hive.  Certain plants produce seeds with fatty nodules on them that ants eat.  Ants collect the seeds and store them in their hives, clipping the edible portions off as needed.  Some of the sees sprout and send their roots into the rich material of the ant hive, reinforcing it and protecting it from rain and predators as they grow.  These hanging ant gardens are found throughout the tropics.

Ant-plant interactions are not limited to the tropics.  Some trillium species bribe ants with food to carry their seeds to good growing locations and elderberries in certain portions of North America keep a protective coterie of ants nearby by bribing them with sugar produces from nectaries grown specifically for the ants.

Co-opting an animal may well be the most sophisticated of plant strategies for its subtly, specificity, and efficiency.  Energy cost is at the root of all these strategies.  A plant only has as much energy as it can collect from the sun and soil nutrients.  It must balance its energy use amongst growth, reproduction, and defense.  Every defense a plant employs lessens the amount of energy it can devote to growth and reproduction.  Combining forces with other species can provide a relatively low-cost way for a plant to gain an aggressive, mobile, multi-pronged defense force.  Ants, for example defend their plant hosts with both physically damaging attacks and with chemicals.  That’s a two-for-one defense with an added bonus of rapid deployment for the relatively minimal investment of a home or some food.

Humans may well be mammal plants have trained best.

***

A note about the images and film vs digital in the field:

These photos (with the exception of the hibiscus leaf which is not mine) were taken in 2005 with a well used and abused Canon AE1 with a 50mm 1.4 lens and scanned from the negatives by the developing kiosks in Peru and Bolivia.  The quality of images reflects both the environmental stresses put on the camera and film and the irregular scanning quality.

For long periods of time in the field I still think that film is the better option.  I was in the jungle for months at a time, sometimes in places with no power (20+ days hiking and on a raft in Bolivia for example) and in hot, humid conditions with frequent thundering downpours and rampant mildew growth.  I love the digital camera I use now, but it would have been completely unusable for the majority of the time I spent in South America.

Film cameras do still have their place.

Chaparral Yucca Seeds, and a Guest

My last post was about Chaparral Yucca, which is blooming in the Santa Monica Mountains right now.  A  few days after writing the post I was exploring Red Rocks Park in Topanga.  This park takes its name from the sculpted sandstone outcrops that rise from the Santa Monica Mountains.

Wind and water sculpted sandstone ledges

Wind and water sculpted sandstone ledges

Like most of the Santa Monica Mountains, this is a dry area, but it is relatively low elevation and nestled in a canyon, the bottom of which has an infrequently running stream and some lovely oak and sycamore trees.

The side slopes are home to the usual assortment of coastal chaparral plants, but the relatively low elevation, slightly greater water supply, and marginally cooler temperatures means that the plants are on an ever-so-slightly different flowering cycle.

Down here some of the Chaparral Yucca (Hesperoyucca whipplei) is still blooming, but other plants are well into the seed setting stage.

Chaparral Yucca seed pods slowly ripening

Chaparral Yucca seed pods slowly ripening

Each of the thorn-like stubs on the branches was a flower.  As you can seen a small percent of the flowers survive to form seed pods.  This year, this is a good crop, in other, wetter, years more might make to this stage.

The pods look like the offspring of a pickle and a ping-pong ball.  Green and slightly warty, divided into three chambers and about the size of a comfortable throwing stone.

Chaparral Yucca seed pod close-up

Chaparral Yucca seed pod close-up

As with the flowers, reaching them is a bit tricky because the basal rosette is composed of lance-shaped leaves crowned with needle tips.  Tips that only seem more aggressive and more prone to break off in your legs as the leaves dry in the increasingly hot summer sun.

Gathering these seed pods was an important activity for many of the coastal tribes as the seeds are edible and nutritious, and unlike the flowers and stalk, the dried seeds can be stored for a long time either whole or ground into flour.

At the moment the seeds are not-yet dried, but are still edible and tasty.

Chaparral Yucca seedpod cross-section

Chaparral Yucca seedpod cross-section

The seeds are flat and black or dark brown, and the capsules look very much like iris or lily seed capsules.  When fully ripe and dry the capsule splits open, disgorging the disk-like winged seeds that flutter to the ground in the frequent coastal breeze.

The green portion of the pod is extremely bitter, so it is best to separate the seeds from the pods for consumption.

The remains of the pods can last for several years in the dry climate.  They look a little like small loofahs hanging on to the dessicated flower stalks.

Chaparral Yucca dried seed pod

Chaparral Yucca dried seed pod

Chaparral Yucca grows in exposed areas in defiance of the sun and shallow soils.  This year even these hardy plants have few blooms and many of the other flowering plants here either didn’t bloom or did so quickly and finished quickly.  Despite the harsh conditions of this year, in some of the darker, damper areas a few plants still show their flowers.

In a little gully, well off the trails, I came across several blooming Scarlet Larkspur (Delphinium cardinale) plants.

Scarlet Larkspur (Delphinium cardinale) still blooming in a shady spot

Scarlet Larkspur (Delphinium cardinale) still blooming in a shady spot

Chaparral Yucca, Spanish Bayonet – the many named Hesperoyucca whipplei

Despite the cool breeze blowing off the Pacific visible 1300 feet below (400 meters) and four and a half miles away (7 kilometers), it is hot.  Blisteringly so.  The sun beats down on me heating my skin like the bank of coals left over from a bonfire.  Across the valleys the slopes of the Santa Monica mountains waver in my vision as the rising heat warps the air, changing its density and bending the light.  At my feet what looks like heat shadows dance, but upon closer investigation I realize that it is a 6 inch (15cm) layer of extremely fine alkaline dust blowing over the trail like a Martian sandstorm seen from orbit.

This is one of the most diverse areas of California for birds, but all I hear is a single crow cawing as it glides over the ridge and falls into the canyon to the west of me.  Dressed all in black, even the crows must be broiling.  Here and there fence lizards and side blotch lizards scurry abruptly across patches of orangey dust leaving sharp trails in the fine powder that flies up from beneath their feet and whip-lashing tails.

Only the flies and ants are active; green bottle flies, landing to steal a lick of sweat from my arms before I shoe them away and inexhaustible armies of red ants collecting seeds to add to their larders.

It is the middle of the day, the time when the Chumash sun god grows weary of carrying the heavy bark torch he carries across the sky and stoops under its weight, allowing the flame to fall close the the planet’s surface.

Here and there on the drably greenish slopes pillars of bright white stand proud, like blowtorches, clearly visible for great distances in the bright sunlight.

Chaparral Yucca (Hesperoyucca whipplei) 3/4 of a mile away through a 300mm lens, uncropped.

Chaparral Yucca (Hesperoyucca whipplei) 3/4 of a mile away through a 300mm lens (8.5 zoom equivalent), uncropped.

These 9+ foot (3+ meter) beacons are the  inflorescences of an iconic coastal chaparral plant and the reason why I am walking in heat that even the lizards are avoiding.

This plant has a number of common names and has recently been reclassified and renamed in the academic literature.  The most common name is simply “yucca”, with the “y” portion pronounced as in “ya-all” rather than “you”.  This is not to be confused with “yuca” (pronounced with the “you” sound), the cassava root, a common food found through much of the tropics.

This particular species of yucca is also known as Chaparral Yucca, Common Yucca, Foothill Yucca, Our Lord’s Candle, Quixote Yucca, and, perhaps the most telling, Spanish Bayonet.  I find the latter name to be particularity evocative as the long, lance-like leaves are crowned with a needle-like point that easily penetrates clothing, only to break off under your skin, leaving a mark that itches for days to weeks as your body works the barb back out.

Like many organisms, this plant has been classified and reclassified, the scientific name changing back and forth as new information comes to light.  It is currently known as Hesperoyucca whipplei, a name coined in 1892 by Georg Engelmann, but it spent many years happily living under the name Yucca whipplei, when it was thought to be more closely related to Joshua Trees than recent genetic analysis indicates that it is.  Perhaps I am lazy, but I have always referred to it as yucca, and will continue to do so, relying on context to clarify which of several I mean.

The inflorescence of Chaparral Yucca is a mighty affair, that stands high above the landscape in defiance of herbivorous predators, protected by its height and the spiky ball of needle-tipped blades below.

Unopened buds at the opt ad a yucca flower stalk

Flowers and unopened buds at the top of a yucca flower stalk

A senescent yucca with a 4 foot (3+ meter) ball of blades dying after blooming)

A senescent yucca with a 4 or 5 foot (1-2 meter) ball of blades dying after blooming)

For many years these yuccas, which are monocots (having simple leaves with no branch-like structures in them) were though to be in the lily family (Liliaceae) on the basis of their flower construction which closely mirrors the multiple sets of 3  and superior ovaries that are a characteristic of lilies.  Now the yuccas have been moved into the Asparagaceae family which includes asparagus, orchids, hyacinths, Lily-of-the-Valley, and the close relative agave, known to most people in its cooked, fermented, and distilled form, Tequila.

Superior ovaries and the parts in sets of 3 and 6

Superior ovaries and the parts in sets of 3 and 6 – this flower had fallen onto a different plant

When you look at the flowers of a plant you are looking at its genitals, a thought that should give one pause the next time you buy flowers for your partner.  Unlike animals, plants cannot wander about to seek their mates and thus many must rely upon intermediaries for reproduction.  The various colors, shapes, scents, and sizes of flowers are meant to attract very specific sexual intermediaries.  Brightly colored flowers are often attractants for birds, butterflies, and bees that are active during the day, long tube-shaped flowers attract hummingbirds and insects with long tongues, flowers with fetid scents often attract flies and beetles.  The yucca has relatively large bright white flowers with a slightly sweet, nutty smell.

Bright white yucca flowers - white flowers often attract night flying animals such as moths and bats

Bright white yucca flowers – white flowers often attract night flying animals such as moths and bats

These highly scented, bright white flowers, so visible during the day, are meant to attract night flying creatures.  In this case a very specific moth, the California Yucca Moth (Tegeticula maculata).  The relationship between the Yucca Moth and the yucca plant is one of mutual dependence; despite all the other insects that come to steal nectar, only the yucca moth pollinates the plant.  As it does so, it deposits its eggs in the developing seed pods, where the larvae grow, eating some of the seeds as they grow.  These moths only lay eggs in the yucca seed capsules.  In return for pollination (sex) the plant sacrifices some of its seeds.  At this point, neither the plant, nor the moth can survive without the other.  The specificity of the relationship suggest that it is an old one.

The yucca plant is incredibly useful.  The long leaves are tough and full of strong fibers.  The whole leaves were woven into mats and sandals.  The fibers were separated and twisted into extremely strong cord; numerous time I have done this quickly in the field when I need a length of twine and do not want to cut the cord I carry in my pocket.  The flower stalk is full of water and sugar, the flowers themselves are edible, more than edible, they are delicious with a delicate nut-like flavor with a touch of bitterness, a little like cashew blended with bitter almond topped with a dash of gardenia scent.  The unripe seeds are edible raw or roasted, and the dried seeds can be ground into flour.

It is not only humans that find the plants useful and delicious, deer, rats and birds all like to eat the tasty bits, many getting water in addition to nutrients.

Yucca inflorescence being browsed on by a hungry animal

Yucca inflorescence after being browsed on by a hungry animal

It takes a yucca plant 4-6 years to reach flowering stage, then, like a century plant, it dies shortly after flowering.  Even while it is flowering the leaves begin turning color.

Yucca basal rosette with leaves dying after plant flowers

Yucca basal rosette with leaves dying after plant flowers

New plants grow from runners and dispersed seeds.

The old flower stalks can remain standing for another year or two before collapsing, often with the shredded remains of the seed pods still attached.

Fallen flower stalk with empty seed pods attached

Fallen flower stalk with empty seed pods attached

This is one of the iconic plants of the coastal chaparral environment, one which I admire, but treat with the utmost respect, having spent far too much time digging leaf-spikes out of my legs and arms over the years.

Things that Gall – plants and parasites

The word “galling” is particularly evocative.  In its most simple form something that galls is merely annoying or vexing, but the true definition connotes annoyance taken to an extreme level.  The sort of thing that will do you no harm but rankles tremendously; much like being forced to pay taxes to support actions you object to.

For us these annoyances are mental and emotional, for plants these galls are physical but are often merely annoyances for them as well.

Dried oak apple gall  on Scrub oak in California

Dried oak apple gall on Scrub oak in California

Many plants suffer from galls and the galls are so singular in form that they can be reliably used to identify individual parasite species.  A fantastic book on identifying plant galls for the California region is the Field Guide to Plant Galls of California and Other Western States.

Oak trees seem to be particularly susceptible to parasites of all sorts and a common manifestation is the Oak Apple Gall, most often seen as a hard, woody ball dangling from a twig.  These galls are created by the Oak Apple Gall Wasp, a common name for a variety of small wasps that inject their eggs into the midrib of a developing leaf and chemically trick the tree into growing a protective shell for the developing larvae.  Despite appearing woody when dried, this type of gall is actually a modified leaf.  The delicacy of these galls is more easily seen when they are still green.

Fresh Oak Apple Gall - Virginia

Fresh Oak Apple Gall – Virginia

The developing wasps browse on the oak tissue and are often preyed upon or parasitized by other animals, including birds, raccoons, and a whole host of insects, other wasps included.  Some insects use the gall for their own protection, sharing the space with the wasp larvae.

Oak Apple Gall with non-wasp larva inside next to a Twig Gall - California

Oak Apple Gall with non-wasp larva inside next to a Twig Gall – California

Certain Oak Apple Galls, the Iron Galls,  in Europe were collected to make ink.  For 1500 years ink make from the iron gall was the primary source of writing quality ink in the Western Hemisphere.  For anyone interested Evan Lindquest provides detailed instructions on how to make your own iron gall ink.

Like may things we have a long history with there is a great body of mythology and folk-lore that has accumulated around these galls.

Many galls are hard and woody, there is a Twig Gall I sliced in half in the photo above.  It appears to be empty, but a dark brown patch filled with frass (insect excrement) can be seen winding its way though the bloated tissue.

Oak Apple Galls often fall from the tree, but Twig Galls are a more permanent fixture of the tree.

Twig Gall on a scrub oak branch flowering from the tip - California

Twig Gall on a scrub oak branch flowering from the tip – California

Right now the Scrub Oak is blooming along the coastal mountains in Southern California.  The twig galls are uniformly clustered near the tips of the branches, with many of them crowned by small clusters of flowers.  This provides a bit of insight into the formation of these and other galls.

The gall must be grown, and while the living plant cells are constantly dividing, the true growth of a woody plant takes place at the tips of the branches and roots, or at the apical meristem of each limb.  The cells in the apical meristem are undifferentiated,having the potential to become a wide variety of plant organs, much like stem cells in animals.  The parasite, be it a wasp, bacteria, or virus, co-opts these “stem” cells and gives them new instructions.  In a way the galls are akin to a tightly controlled cancer initiated by the parasite organism.

The Twig Galls I was looking at today were insect formed and, as such, the insect needs to escape the protective structure once it is mature.  Many of the galls had little holes in them showing where the little wasps has crawled out.

Exit holes in a Twig Gall - California

Exit holes in a Twig Gall – California

The variation in galls is astounding.  I have seen leaf galls on wild roses that look like tiny sea-urchins dipped in vermillion.  There are galls that not only force the plant to grow a protective structure around it, but that trick the plant into producing nectar to attract ants which in turn protect the growing larvae from predators.  Many are extremely colorful and the shapes are widely varied.

Colorful leaf galls on a Sugar Maple leaf - Vermont

Colorful leaf galls on a Sugar Maple leaf – Vermont

The common theme is that the galls are all formed in developing tissue, leaves, new twigs, flowers, roots, or fruit.

A gall on Shadbush fruit - Vermont

A gall on Shadbush fruit – Vermont

Some of the Ichneumonidae wasps that make so many of the galls we see have developed a biological metallurgy, evolving zinc and manganese coated ovipositors which they use to inject chemicals and hormones into the plants they co-opt.

The specificity and regularity of the galls and the relationships between the plants and the gall formers speaks to a lengthy and complicated evolutionary history.

We pride ourselves (or are horrified by) our newly found ability to genetically manipulate plants and animals.  In truth, we have a long way to go before we catch up to what we often mistakenly call the “humble” insects.

Spring comes to Madrid

Spring is lurching its way through the Northern Hemisphere.  In Madrid this year this means more rain than has fallen since the 1940s, usually in a soft drizzle, occasionally spiced with small hail, bouts of hard rain, and periods of epic cloudscapes accompanied by bright sun.  It is familiar weather, reminding me of the part of California I grew up in.

In the countryside the effects of all this water are obvious, the land turns green.  This is likely to be a good year for farmers and wildflowers, though the former have a globally recognized habit of finding something to complain about no matter the weather.  For the wild plants this may mean bountiful seeds next year and the possibility of mast fruiting for woody plants that do that sort of thing (oak trees, I’m looking at you).

Within the boundaries of Madrid, where I have been living recently, the setting is considerably more urban.

The early evening view from a Madrid apartment

The early evening view from a Madrid apartment

In this landscape of stone, cement, and brick the effects of spring are more subtle and easy to overlook; they are most clearly seen in the length and material of coats worn by pedestrians.  Long black wool overcoats are being replaced by short black wool overcoats, leather jackets are replacing down, and on the few warmer days some of the women wear skirts with tights and accompanied by peculiar choices in footwear.

Nature-wise the heralds of spring are the street trees which are beginning to leaf out (especially the elms); ornamental cherries, plums, and almonds have been blooming, and, most interestingly to me, the little plants that have adapted to city life are beginning to show signs of life.

Leaves of an elm seedling

Leaves of an elm seedling

On the patio there is a planter box that has been left to what wild nature resides in the city.  A small elm has taken root and shows nice bonsai potential.  Accompanying the elm are, moss, English Ivy (planted), a few tender oxalis plants, and a small climbing vine with miniscule, but lovely, flowers; purple and white, kissed with egg-yolk yellow.

Leaves and flowers of our mystery plant - the flowers are perhaps half a centimeter across and at most a centimeter long

Leaves and flowers of our mystery plant – the flowers are perhaps half a centimeter across and at most a centimeter long

This plant starts out in a tight cluster and flowers prolifically when conditions are right.

A tangled clump of Ivy-leaved Toadflax (Cymbalaria muralis)

A tangled clump of Ivy-leaved Toadflax (Cymbalaria muralis)

This little plant, Ivy-leaved Toadfax (Cymbalaria muralis) is evergreen and originally native to the Mediterranean region, now found nearly globally, having been introduced both intentionally and inadvertently. The flowers betray the family association; snapdragons or Scrophulariaceae.

Cymbalaria muralis does not suffer from a lack of names, Coliseum-Ivy , Kenilworth-Ivy, Wandering-Sailor, Mother-Of-Thousands, Oxford-Ivy, Pennywort, and Ivy-leaved Toadflax being just a few of its common names.

Ivy-leaved Toadflax prefers calcareous soils and often grows directly from cliffs and older walls.  Here in Spain it is a native plant and is as much in balance with its environment as any other plant is in a land so heavily used by humans for so long as the Iberian Peninsula has been.  Elsewhere this small plant becomes aggressively invasive and can rapidly form a dense blanket of vegetation over trees, cliffs, and buildings.  It is a popular plant for rock gardens.

If a plant could be described as being clever, this plant might qualify for the compliment.  It sends runners out in all directions, with most of the ones I have seen pointing upwards.

Ivy-Leaved Toadflax climbing a trellis

Ivy-Leaved Toadflax climbing a trellis

On a healthy plant these runners can be nearly a meter long and have a fleshy, almost succulent aspect.  The leaves and the vines are slightly waxy and smooth to the touch, helping to limit water loss.  As it grows, Ivy-leaved Toadflax builds up a dense, nearly light impenetrable, layer of overlapping leaves.  Like a forest, this little clump of shade helps to trap both moisture and organic matter.  This little reservoir of nutrients feeds the ever growing plant.

The most interesting aspect of this plant is its behavior when it flowers and sets seed.  The flowers are pollinated primarily by bees and must be placed where the bees can find and land on them.  To ensure this the young flowerbuds are positively phototrophic; they actively seek out the brightest light.

Cymbalaria muralis flowers growing towards the light

Cymbalaria muralis flowers growing towards the light

Bees can see into the ultraviolet and to them flowers look very different than to us.  I am very curious how these flowers look to the bees.

Once the flower has been pollinated a change takes place and the forming seedpods become negatively phototrophic actively avoiding light.  The change can be quite dramatic and rapid

A fertilized bud running from the light

A fertilized bud moving away from the light

Avoidance of light sends the forming seeds into the darkest places within reach, places where it is more likely to find a safe, damp spot for the small seeds to be deposited.

Light and dark seeking stems

Light and dark seeking stems

This clever approach to seed distribution combined with rooting from runners and re-rooting from broken clumps serve the Ivy-leaved Toadflax well.  This change in light preference is not unique to Ivy-leaved Toadflax, the common houseplant Monstera deliciosa (aka Swiss Cheese Plant, Window Leaf, Mexican Breafdruit, and many more names) begins life avoiding light, then, when it finds a tree trunk its preference turns towards light as it climbs to the near canopy.

We don’t often talk about the behavior of plants, we usually use more neutral terms such as survival strategy.  To us plants are fixed in the landscape with their changes slow.  Plants lack of a brain makes discussion of behavior problematic.  We often fail to have an appreciation for the senses plants posses and they way their response to stimulus drives their growth and adaptability.  We have a prejudice for organisms with a central nervous system, or at least some form of mobility, because they are more similar to ourselves and we find them easier to empathize with.

The little Cymbalaria muralis is far from the only plant in flower right now in Madrid.  In the parks Common Fumitory (aka. Earth Smoke), Fumaria officinalis, is blooming.

Common Fumitory, Earth Smoke (Fumaria officinalis) flowers

Common Fumitory, Earth Smoke (Fumaria officinalis) flowers

Common Fumitory is in the Bleeding Heart family, related to Corydalis, Bleeding Hearts, and Squirrel Corn.  Often this pretty little plant is lumped into a sub-family of the Poppy family (Papaveraceae).

In some places small fields of Red Campion (Silene dioica) dance in the breeze, making rippling patches of purple-tinged pink.

Red Campion (Silene dioica)

Red Campion (Silene dioica)

In the countryside ground dwelling orchids are beginning to bloom, but I have not seen those yet.

Perhaps soon.

Into the forest at Lubuk Baji – Part 2: Monkeys and Apes

The real temperature was not so great, perhaps 83°F (28°C), but the humidity and the still air in the forest made it seem hotter.  I took large, slow strides, my toes instinctively trying to grip the slippery, steep slope through my sandals, my sleeves rolled down to keep the constant flow of sweat from dripping down my arms onto my camera bag.  A bandanna looped around my neck served as a towel to mop sweat from my face, sweat that stung my eyes, sweat that was so prodigious that it felt like the inside of my mouth was sweating.

Bird calls, the occasional ululating call of a gibbon, and the clicks and whirrs of numerous insects surrounded us.  Despite the fecund richness of the forest around us the only animal life to be seen were insects, most obviously large butterflies, predominately black in color, some with large yellow patches, others with cerulean blue patches, many with white polka-dots scattered over their wings.  In the warm air they rarely stood still, preferring to dance in the solitary shafts of sunlight and flit erratically through the trees.

Large butterflies were common in the forest, many about the size of an open hand

Large butterflies were common in the forest, many about the size of an open hand

On the forest floor, amongst the leaf litter crawled the occasional giant woodlouse, relatives of common pillbug but far larger.  They would curl at the slightest provocation, looking like painted ping-pong balls.

Giant woodlouse curled up on the forest floor

Giant woodlouse curled up on the forest floor

We were looking for wild orangutan in the hills of Lubuk Baji.  We knew they were in the area, abandoned sleeping nests in the trees and their pungent scent attested to their recent presence but they remained hidden in the forest.

Lubik Baji is a small hill on the west side of Gunung Palung National Park in West Kalimantan, Indonesia.  This large park is one of the last remaining protected lowland forests and contains nearly 10% of the world’s remaining orangutan.  The nearby town of Sukadana is partially surrounded by the park and a large number of people live nearby, many of them relying on resources found within the park for their livelihoods, especially timber resources.

Gunung Palung NP wraps around Sukadana, to the east is a small hill names Lubuk Baji

Gunung Palung NP wraps around Sukadana, to the east is a small hill names Lubuk Baji

We had seemingly missed our chance to see these large forest dwelling primates, perhaps arriving too late in the day.  Our guide kept a close eye out and several times pulled us off  the trail through small tangles of spiky rattan palm to follow up on potential sightings and sounds.  Each turned out to be a false alarm.

Wandering off the trail brought its own rewards though.

Large ground orchid in the Borneo rainforest

Large ground orchid in the Borneo rainforest

Where the ground was a bit more damp large white ground orchids grew, the broad, soft leaves looking more lilly-like than orchid like.

Unknown red & blue fruit (if you know, please let me know).

Unknown red & blue fruit (if you know, please let me know).  Each blue fruit was only about 1 to 1.5cm long.  EDIT: possibly Baccaurea odoratissima

The tree above was fruiting directly from the trunk.  This is a trait called cauliflory.  Plants that exhibit cauliflory flower and fruit directly from their stems and trunks.  It is relatively common in tropical environments and rare to non-existent elsewhere.  I have seen it on many plants in the Amazon, but the fruit growing in this manner that most people will be familiar with is papaya.  I think it is one of the most striking and beautiful ways for a tree to flower, in part because it is so unexpected.

I have heard several hypotheses for why tropical trees do this; one has to do with sun protection for delicate flowers and fruits.  Tropical sun is intense and the trees may be protecting their fruits under a dark canopy.  Another thought is that it makes the fruit easier for large animals to reach as they do not have to rick precarious trips onto thin branches that may not hold their weight.  One side effect of this growth form is that trees can produce fruits of immense size.  Jackfruit (Artocarpus spp), a delicious fruit of which there are many species, produces some of the largest fruits of any tree, the largest fruits weighing up to 80 pounds (36 kilos).

Failing to see any wild primates we continued our hike along the ridge to an overlook of bare granite shaded by a grove of tall bamboo.

Looking East-Northeast over Gunung Palung National Park and parts north from the Sukadana Hills

Looking East-Northeast over Gunung Palung National Park and parts north from the Sukadana Hills

From here we finally got an overview of the surrounding countryside.  Views like this can be surprisingly rare in forested lands, even when there are hills and mountains.  Below us rice paddies infringed on the edge of the national park, then faded into a shaggy carpet of greenery.  Here and there eskers of logging tracks could be seen following stream courses and through binoculars it was clear that all the tall trees had been cleared from the lower slopes of the distant hills.

We sat enjoying the breeze and view for a time, then headed back to the stream and park building for lunch.

I grew restless and maybe 15 minutes before we were to set out I told the guide that I would go first and wait for the rest of the group later on.  Walking in nature in large groups always bothers me a bit, too many people talk too loudly, make too much noise moving through the forest, and scare off the wildlife.  I tend to walk slowly and quietly with frequent pauses to listen, look, and smell the air.

As it has so many times in the past my slow approach to nature paid off in spades.  Just downhill from the honey gathering tree I saw a large branch move across the stream and head a loud rustle, clearly not from the wind.  I froze and waited, watching the closely.  Large dark shapes clambered about, difficult to see, sometimes in deep shade, other times so strongly backlit by the sun that all I could see was a dark blob.

I waited with my camera out.  After a few minutes of quiet waiting the orangutan began moving about, foraging and breaking off large dead limbs.  I waited until they seemed accustomed to my presence, then slipped back up the trail to wait for the rest of my hiking group.  Five minutes later they came down the trail, talking and breaking dead branches on the ground.  “Shhh, tiga orangutan,” I said holding up 3 fingers.  Everyone fell silent and we crept down the hill.

The orangutan watched us for a few minutes, then returned to foraging.  One adolescent clambered directly over us, occasionally peering down through the sheltering leaves, then moving on again.

Very curious adolescent orangutan

Very curious adolescent Bornean orangutan (Pongo pygmaeus)

Most of my photos did not turn out well, the contrast was too great and the apes moved too quickly.  After much post processing one image revealed that there were at least 4 orangutan, possibly more nearby.

After about 20 minutes we continued on our way down the hill, pausing to swim in a deliciously refreshing pool at the base of a waterfall.

The trail was paralleled by a series of lovely waterfalls

The trail was paralleled by a series of lovely waterfalls

Regretfully donning our clothes once more we continued our hike out of the forest, happy at seeing the orangutan and thinking that out wildlife sights were at an end.

Just inside the margin of the forest we found that we were unexpectedly and happily wrong.

Red leaf Monkey (Presbytis rubicunda), aka Maroon Leaf Monkey

Red leaf Monkey (Presbytis rubicunda), aka Maroon Leaf Monkey

Several Red Leaf Monkeys were foraging for fruit in the semi-wild durian orchard.  They made long, graceful leaps between the trees, their tails streaming out behind them, accenting the arc of their flight.

People often think we need to protect the forest in order to protect species like the orangutan, various monkey species, birds, and other forest inhabitants.  While this is indeed true, it is only part of the picture.  The forest denizens must be protected as well because without them the forest changes, sometimes radically, becoming a completely different environment.

Many species of plants require their seeds to be consumed along with their fruit and carried far off as part of their dispersal strategy.  Many seeds must pass through the digestive tracts of specific animals before they will germinate.  The extinction of one animal species can have repercussions that are slow to manifest, are difficult to reverse, and may have a wider impact through the ecosystem.

We often talk of specific species as being keystone species.  It may be wiser to think of all species as being keystone species.

Red Leaf Monkey watching me

Red Leaf Monkey watching me