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.

Hummingbirds – miracles of evolution

Of all birds hummingbirds are one of the most fun to watch.  They are fast, colorful, and tiny, the smallest ones roughly the same size as a large moth or butterfly.  They are probably best known for their maneuverability.

Anna’s Hummingbird (Calypte anna) coming in for a landing. Note the small tail, the curve of the body, and the large wing muscles.

These birds are compact and extremely well muscled.  Their tails are short and flexible, notice how the tail of the Anna’s Hummingbird in the above photo is curved to the side and folded to cup the air to assist in guiding the bird in to its landing spot.  Their wings are short with thick muscles covering the limbs and have a range of motion far greater than that of other birds.

The name Hummingbird comes from the noise of their wings beating at 25 beats per second, about 1500 beats per minute. This high wing-beat and the extraordinary wing flexibility allows hummingbirds to hover far more effectively and energy efficiently than any other bird.

To hover they flap their wings in a figure-8 pattern, generating lift on both the down and upstroke.  Approximately 75% of the life of generated on the down-stroke with the remainder on the up-stroke.  The University of Texas has some nice graphs and charts providing more detailed information on how this works.

Anna’s Hummingbird hovering in front of Tobacco Tree (Nicotiana glauca) flowers

In to achieve this maneuverability hummingbirds give up the ability to glide.  In effect they have no low energy flight, they are always running at near full speed.  A 170 pound person would need to eat (and metabolize) 130 pounds of bread a day to keep up with energy output of a hummingbird.  Their energy output is so great that they enter torpor at night, a sort of hibernation.  If they did not do this the hummingbird would starve to death during the night.

Hummingbird flight characteristics are very nearly a blend of bird and insect methods of achieving lift.

Hummingbirds are generally extremely colorful, especially the males.  Like many birds this color is not pigment generated, but is the result of highly specialized feathers light refracting feathers.  Think of oil on water, that rainbow sheen that you see when light reflects from it.  Birds use the same technique, but in a far more specialized way.  Rather than an undifferentiated rainbow of colors the micro-structure of the feathers refracts only specific colors.  The natural color of the feathers is a dark brown, almost black.

Anna’s Hummingbird (Calypte anna) perched on a non-native Tobacco Tree (Nicotiana glauca)

I know I’ve used this photo before, but it illustrates the refraction vs pigment issue well.  The bold purple-pink behind the bird’s eyes is the color we associate with the male Anna’s Hummingbird’s head and gorget (the throat portion).  The dark, almost black, feathers are at the wrong angle to reflect the light and show the natural dark color of their pigment.

The tree in these photos is a Tobacco Tree (Nicotiana glauca), not native to North America, but native to South America, a place where there is a stunning variety of hummingbirds.  This tree and hummingbirds have a long relationship and have mutually evolved to reinforce that relationship.  Hummingbirds and may other birds and insects (and not a few mammals and reptiles as it turns out) drink nectar from flowers.  Not everyone who drinks the nectar will pollinate the plant, thus special relationships evolve.  Plants with long tube-like flowers (penstemon, humming-bird sage, tobacco, monkey flowers, heliconia, etc) are specialized to provide nectar for animals with long tongues that can reach the nectar.

Hummingbird tongue

Hummingbirds not only have long, narrow beaks, they have long, feathery tongues with which to lap up nectar hidden deep inside the tube-like flowers.  As they drink the plant deposits pollen on the beak and sometimes the bird’s head (two photos up you can see the pollen discoloring the hummingbird’s beak).  The next flower the bird visits gets a little pollen from the previous flower and the plant is happy.

A quick look at the shape and color of flowers will often give you a good sense of what type of animal the plant relies on for pollination.

Hummingbird catching insects under a Coast Live Oak

Hummingbirds need protein as well.  Some, such as the Anna’s Hummingbird, catch insects in flight, many others raid spiderwebs for insects.  Here in North America this is a relatively safe prospect, but in parts of South America there are spiders that will happily catch and eat a hummingbird and spin webs more than strong enough to trap the birds.

Hummingbirds have such a need for vast quantities of high energy foods that they are often extremely territorial, engaging in vicious fights and high speed chases.  Like most animals they would rather warn opponents off than waste energy fighting them.  Different species have various methods of letting others know how tough they are.

Anna’s Hummingbird staking out its territory

The little fellow above is marking out territory by fluffing out his head feathers.

One of the most amazing things about hummingbirds to me is that they migrate long distance, some species crossing the Gulf of Mexico in one long flight with no food.  At the shortest distance this is a flight of 480 miles, many birds fly closer to 600 miles to make this open water trip.  For a bird that only weights several ounces, cannot glide, and needs to eat constantly this is a truly remarkable voyage.

On a final note, hummingbirds are far more intelligent than most people realize.  Their memories are phenomenal, allowing them to keep track of individual flowers within their territories and when they were last visited for nectar.  They have the largest brain-to-body size of any bird.

Away Dog! Apocynaceae, the Dogbane family

Near my house, next to the road the ground is sandy with a scattering of pebbles in the mix.  Like much of Vermont what is not bedrock is ground up glacial debris deposited when the vast continental glaciers melted away.  The ground is sandier than most places at my house because I am perched on the southern slope of a small rock outcrop, a place where the downward pressure of the glacier was lighter, water flowed under the ice, and fine sediment was deposited.

In that sandy ground there are wild strawberries, mosses, dandelions, fleabane, hay scented ferns, a few coneflowers, some potentillas, Allegheny blackberry, a little bracken fern, and a small stand of dogbane (Apocynum cannabinum) with delicate pink flowers.

Hemp Dogbane (Apocynum cannabinum)

Before moving to Vermont my only experience with this plant was via books.  I always wondered why it was called Dogbane.  Was it like negative catnip for dogs?  Or was it simply toxic to dogs?  Apparently it is a toxin, and not just to dogs.  Ingestion of any portion can induce cardiac arrest and both the family and genus name literally translate to, “Away Dog!”  Apocynum cannabinum has, thick, milky sap, much like a milkweed, indeed Milkweeds (Asclepiadoideae) are now considered to be a subfamily of the Dogbanes (Apocynaceae).  Other members of the Dogbane family include two of my least favorite plants, Oleander and Vinca, both from the Mediterranean and common in California where they were introduced as ornamentals.  Oleander can be seen in any urban environment in Southern California, most often as a highway divider plant.  The sap is extremely toxic, raising painful rashes, and the smoke can be lethal if inhaled.  Vinca, more commonly known as periwinkle, is  common in Northern California where it invades riparian areas, covering both ground and small trees in a dense, vining mat of glossy green leaves studded with pretty blue flowers.  It is nearly impossibly to eradicate once in place.

In the past some Apocynaceae species were used to make a poor quality rubber, others for toxin to apply to arrows.  Some species produce edible fruit and others edible flowers.  We extract heart drugs from a few of them as well.

The dogbane in my yard, Apocynum cannabinum, is a traditional North American source for extremely strong fiber, hence the “cannabinum ” species name, referring to the hemp-like characteristic of the plant.  Common names run from simply Dogbane, to Indian Hemp, Wild Cotton, and Hemp Dogbane.  The fibers are stripped from the stalk in late fall and can be twisted into a fine, strong cord.  Cords made from dogbane were prized for their great strength and used for sewing, fishing lines, and other work requiring fine cordage.

The Hemp Dogbane ranges from calf high to chest high.  The ones in my yard top out at waist high.  The have an odd branching structure, perhaps best described as irregular opposite.  The main stalk continually divides in a binary fashion, with one side acting as a dominate leader, this pattern is often repeated on the side branches, but in some cases buds on both side of the stem will form side branches instead.  The result is a roughly Y shaped plant that rapidly spreads as it grows.

Apocynum cannabinum whole plant.

The leaves are opposite and the undersides are covered with a fine pubescence.  I expect that the hairy leaves are an adaptation to help cope with moisture stress.  Plants often evolve this trait to create a boundary layer of trapped, still air that aids in preventing moisture from being blown away.  The upper leaf surfaces have a matte waxy texture, a little like nasturtium leaves.  Water beads and runs off of them rapidly.

Apocynum cannabinum leaf hairs

The seeds are held in long, horn-like pods.  This time of year few of the seed pods have developed, but a couple of plants are a little further along in the cycle than others.

Apocynum cannabinum seed pods, not fully developed

Few of the leaves have any insect damage, but the flowers are popular with a number of insect species.  I’ve seen ants, flies, bees, and moths going to them.  Hidden amongst the flowers are predators as well.  The Goldenrod Crab Spider (Misumena vatia) seems fond of my dogbane.

Goldenrod Crab Spider (Misumena vatia) playing parlor games with a fly

Goldenrod Crab Spiders are so called because they often hide amongst the bright yellow flowers of goldenrod, a common meadow plant in New England.  The spiders change color from white to yellow and back again based on input from their eyes.  The yellow color seeps up to stain their carapace, providing camouflage.  When they move to a pale flower the production of this pigment stops and the spiders slowly turn white once more.  Experiments show that the spider will not change color if it cannot see what color plant it is on.

These are not web building spiders, they are ambush hunters, grabbing unsuspecting prey in their wide arms.

The smell of the flowers is odd and difficult to describe, incorporating many scents including a dusty sweetness and a faint rankness like dried meat on the edge of going bad, but they are pretty.

Blue-Eyed Grass, diminuitive irises

From California to New England, from Alaska to Texas there is a small, easily overlooked wildflower that is blooming now and will continue to do so for several more months, depending on where you are of course.  The flowers of this plant are small, only a little more than a centimeter across have six petals, a yellow center, and are often blue in color, hence one of the common generic names, Blue-Eyed Grass, although there are yellow and white variations.  To see them clearly you have to get close, crouching or laying on the ground.

Common Blue-Eyed Grass (Sisyrinchium montanum)

You can see from the photo that the leaves of this diminutive plant are broad and flat, much like the leaves of the grass it grows amongst.  In Vermont there are several variations of this plant, Sisyrinchium montanum being the most common, hence the name, Common Blue-Eyed Grass, which is, unfortunately, not tremendously imaginative.  When it is not flowering it’s easy to see why it might be mistaken for a grass, it has a similar leaf shape and is of a similar height to the grass it grows amongst.  The flowers clearly set it apart though.  Petals are little flags to attract insects, birds, and in some cases lizards or mammals to the flower for pollination for which they are rewarded with nectar.  Grasses have no such need, like willows, poplars, and pines they rely on wind to distribute their pollen and petals are a hindrance and a waste of energy for a plant that uses wind rather than animals for pollination.

Wind pollinated grass flowers with Blue-Eyed Grass flowers in the background

Sisyrinchium, the Blue Eyed-Grasses are tiny irises.  The Iridaceae family is widespread and often used as ornamental plants in gardens or in bouquets.  The larger irises have showy, ornate, soft flowers that fold and flow in complicated shapes, looking little like the small, robust Sisyrinchium flowers.  In the wild, the larger irises tend to grow in places that are either damp, shady, or both.  The Blue-Eyed Grasses live in harsher regions, open meadows, occasionally on rocky ledges, the edges of open areas, in short, places that can get hot and dry.  This may partially explain their small, robust stature.

Like other irises Sisyrinchium has inferior ovaries, this is not a commentary on the quality of the ovaries, it is a botanical term meaning that the ovaries are below the flower rather than the flower surrounding the ovaries.  These little plants produce globular three-part capsules about the size of a BB filled with numerous little seeds.

Blue-Eyed Grass with immature seed capsules

I grew up looking at these little flowers on the wildflower rich coastal prairie of Northern California, but just a few days ago I discovered something new (to me) about them.  They are active, they open their flowers for the day and close them for the night.  I tried my hand at a time-lapse of a flower opening.  It’s a bit rough, but you get the picture.

Blue-Eyed Grass flower opening animation

I love finding out things, being surprised by life, experiencing the unexpected, and encountering things I do not know.  I’m glad that these little irises reminded me that such a small, seemingly mundane thing can be interesting and exciting.

Quaker Ladies in the field

We rarely ever take the time to look at the smallest things.  We, very understandably, ooh and ah over vast landscapes, priding ourselves on climbing a mountain for the view that extends to the increased horizon.  All too often we overlook the smaller horizons, those under our feet, those that the vast majority of life with eyes sees.  The nearby, the up close, the things easily flattened under our feet in our quest for the big, the far, the distant.

Right now the Houstonia caerulea are blooming.

Field of Houstonia caerulea

They are known to most of us as Bluets and to some as Quaker Ladies. They grow in small cluster on the edge of meadows and in rich woods on well drained soils that get filtered light or short periods of direct sun. The flowers are often less than a centimeter across.  Most of the time we briefly admire them from where we stand, glancing down at these delicate flowers barely standing above the moss, leaf-litter, or short grass.  From our height the blue can be a mere suggestion of color, dominated by white.  The bright yellow star-like centers are barely visible.

From a little closer more details become apparent, but this invloves lying on the ground, thus most of us rarely see these little gems up close.

Small clump of Houstonia caerulea

It’s worth doing so, they are very pretty.

With a hand lens more detail becomes evident.

Houstonia caerulea iPhone with hand-lens

The vast majority of life with eyes on earth is tiny.  Their view of the world is more like the last photo than the first.  What we barely notice is a deep, dense forest to other living things.  When I can, I like to explore the world from this perspective, it reminds me of where we stand in the wider cosmos.

 

Bryophyta, Ancient and Tough

An ancient creature is waking up.  These creatures are small in stature but extremely tough.  They have been around longer than plants, although we often lump all green sessile things together.  Mosses are different though.

They have neither roots, nor vascular tissue, the plant equivalent of our circularity system.  They anchor to the substrate with little hold-fasts, somewhat like those giant algae, sea-weeds, and they drink though diffusion and osmosis.  They do well in places that are rich in airborne moisture.

Another things mosses lack is flowers and the associated seeds.  Like ferns, club-mosses, horsetails, and fungi mosses reproduce by spores.  By the millions.  They invest in quantity over quality and don’t pack any food or protection for their offspring before they cast them to the wind.  The spores will only germinate under perfect conditions.  Orchid growers are familiar with this problem, as orchids try the seed equivalent of this strategy.  Their dispersal strategy is like colonizing the galaxy by putting people in zip-lock bags and flinging them out of the solar system in the hopes that one of them eventually hit an earth-like planet.

This time of year the capsules that held the spores look like fossilized wind-socks.

Mosses are incredibly tough and individual stems from a colony can be very long lived.  A common way of judging the age of stair-step moss is the count the feather-like branches on a stem.  Five and seven year old moss stems are common and there are other mosses much longer lived than that.  An established moss colony may been in place for thousands of years.  Especially colonies in cold environments.

In the northern hemisphere we tend to think of plants and animals going dormant in response to cold.  If you can prevent the water in your tissues from freezing the danger for plants becomes one of dehydration.

Mosses, as I have said, are tough.  And Ancient.  They have some tricks they have learned over the hundreds of millions of years they have been around.  They learned these tricks before the ancestors of most of the things we see around us evolved.  Dinosaurs are latecomers to the party by the standards of the mosses.

Mosses dry up.  In a way the lessons learned as a spore transfer to the adults.  Most of their water evaporates, and as it does so the moss tissues curl in predictable ways.  The pores through which they breath close. Mosses can wait a long time like that.  Some mosses are so good at surviving this way that they grow in deserts.

Air in cold environments often contains less moisture than desert air.  Vermont has been even dryer than usual and many of the fir-cap mosses are still tightly furled, waiting for water.  Many look like the dry spires in the picture above.

Others have found enough water to wake up.

Like sponges, moss colonies trap water and fine debris.  The debris falls to the ground in the suddenly still water and becomes a nutrient supply for the mosses once they rehydrate.  Much like flowers they open as their tissues fill with water.

The growing tip opens as it hydrates revealing a tight furl of nascent microphylls (moss and clubmoss leaves) tinged a rosy hue.  Cold is well and good for living slowly, but growth requires warmth and the tips of the moss are shaped like little parabolic reflectors.  They trap both water and the sun’s light.  The reddish color may help them adsorb the long-wave understory light once the forest above leafs out.

From now through summer the new spore capsules will ripen, and come fall and winter they will scatter their spores across the landscape to drift with the wind, flow with the water, and run across the snow.

Unlike the poor fellows in zip-lock bags hurtling between the stars, the mosses have stacked the odds a little for their offspring.

Where water splashes moss may grow.  Where wind dies and lets drop what it carries moss may grow.  Where snow is late to melt moss may grow.

NOTE: The three close-in photos were taken though a 10x hand-lens held to the front camera of an iPhone4.