Wednesday, September 20, 2017

The Chill Alarm

The first chilly weather of late summer or early autumn certainly catches the attention of humans and wildlife alike.  After months of hot weather, it is a welcome reprieve for both but it is of more significance to our wild neighbors.

Though animal behavior is most closely tied to the daylight cycle, the cool weather is an instinctive alarm that the harsh months of winter lie ahead and that harvesting is now especially important.  That may mean putting on a layer of fat for hibernation, fueling up for migration or storing food in dens or natural cavities for the lean months.  In response to this seasonal alarm, wildlife species become more active and conspicuous, delighting many humans who are also invigorated by the chill.

Last night, our low temperature dropped into the mid forties (F), kicking on the furnace for the first time since April; the first prolonged run of chilly weather is expected to arrive by this weekend.  This morning, I toured the farm, taking in the cool fresh air and watching our resident birds and mammals as they began their initial preparations for winter.

Tuesday, September 19, 2017

Hurricanes send a Message

After enduring widespread destruction from Hurricanes Harvey and Irma, North Americans and residents of the Caribbean now face Hurricane Maria, churning toward the Virgin Islands and Puerto Rico.  Just upgraded to a category 5 storm, Maria has become the third major hurricane to threaten the region within the past month.

While much of our focus has centered on evacuation and recovery, the elephant in the room is global warming which may not increase the frequency of hurricanes but will surely augment their intensity.  Tropical storms and hurricanes are heat machines, fueled by warm ocean waters and the hot, humid air into which they move.  Global warming will increase all three factors as sea temperatures rise and a warming atmosphere retains more water vapor.

Unfortunately, while many industrialists and politicians appreciate the technology that predicts the path and intensity of hurricanes, they reject the science of climate change.  Few cities are planning for a warmer climate and politicians continue to fight over funding for infrastructure.  The message sent by these powerful storms should resonate across the globe; few if any regions of the planet will be immune to the effects of a warming climate. 

Monday, September 18, 2017

Apache Jumping Spiders

Sitting on a railroad tie along one of our flower beds, I looked down to see a small group of jumping spiders in the dry, weedy grass.  Yellow-orange patches on their cephalothorax and abdomen indicated that they were female Apache jumping spiders, a species common across central latitudes of the U.S.

Like all jumping spiders, they have excellent vision, provided by four pair of eyes (including a large, dominant pair).  Foraging in the bright sunshine, they search for a wide variety of small insects and will return to their den if clouds role in.  Unlike many spiders, jumping spiders do not spin webs but do use silk to create a nest for their young or a cozy retreat for themselves; the nest is typically placed in a protected crevice among rocks or logs.  The life span of these small, active arachnids is generally about one year; Apache jumping spiders overwinter in their immature stage.

It is always interesting to come across small creatures that, if not for sheer luck, might otherwise go unnoticed.  Some landscapes, such as our weedy, dry "lawns", would not seem attractive to many species of wildlife; but, if we stop and look, we are often surprised to discover an amazing diversity of fascinating creatures.  Backyard safaris are often rewarding.

Sunday, September 17, 2017

Borrowing Genes

All life forms on this planet, from fruit flies to humans, borrow genes that determine their physical and behavioral traits.  Having received half of their genome from each parent via sexual reproduction (or all of it in lower forms that are asexual), the genes are a blueprint for our structure and the biochemical processes that sustain life.  Many human genes date back to ancestral primates, having persisted through natural selection during 60 million years of evolution.

Unfortunately, some genes are harmful or corrupted, producing disease or failing to block disease processes; most of these bad genes were inherited while some mutated from good genes during our lives.  We have long used medication and surgery to deal with the effects of this "malware" in our chromosomes and are just now beginning to use gene therapy to correct the defects in our genome.

In the course of our lives, we may pass along some of our genes to biologic children, including some that may threaten their health.  As the saying goes, "we cannot choose our parents" and we are subject to any deleterious genes that we inherit.  Finally, upon our death, a sizable fragment of our genome persists in our biologic children; the rest is removed from the genome of our species, never to be returned.

Saturday, September 16, 2017

Engaging North Korea

Despite the saber-rattling and bombastic threats from the two narcissistic leaders, neither North Korea nor the United States has anything to gain from a military confrontation.  Though some war hawks in Congress are pushing for a tough stance, diplomatic engagement is the best answer in the long run.

It may be difficult to demonstrate respect for a dictator who brain washes and oppresses his citizens but we cannot encourage change by isolating and ridiculing Kim Jong Un.  Efforts to bring North Korea into the world economy will produce opportunities to shine light on the inequities that exist in that country and better introduce its population to the freedoms enjoyed in Western Society.

If Kim Jong Un is granted a more significant role on the world stage and if other major players initiate diplomatic relations with North Korea, we should be able to avoid military conflict and eventually bring that country into the international community.  Warfare, on the other hand, will lead to the death of thousands (if not millions) of innocent civilians.  See also War and Speech.

Thursday, September 14, 2017

The Second Coming of Man

Earth formed about 4.6 billion years ago, some 9 billion years after the Big Bang.  Life would appear on our planet a billion years later but would not emerge from the sea until 440 million years ago.  Primates evolved about 60 million years ago and the first hominins appeared about 5 million years ago; finally, modern man graced the scene about 150,000 years ago.

While our species had a limited effect on natural ecosystems for most of our history, we began to significantly pollute the planet over the last few centuries.  Fouling the air, water and soil, we have also altered the climate through our widespread use of fossil fuels.  There is a reasonable probability that Earth may become uninhabitable within a few more centuries unless we make major strides in the areas of population control and pollution curtailment.  Of course, supervolcanic eruptions, asteroid strikes and nuclear war could also play a role in our extinction.

Many humans envision that we will escape to other planets or other solar systems before our species is annihilated.  More likely, it seems to me, we will fall victim to our lack of stewardship, perhaps aggravated by natural catastrophe, and, in our absence, nature will heal herself.  Hundreds of millions of years later, assuming the sun has not yet begun to die, we may re-evolve from "lower species" that managed to survive the turmoil on Earth.

Saturday, September 9, 2017

Irma's Fury becomes Personal

As I write this post, Hurricane Irma is still meandering WNW along the northern coast of Cuba.  The most recent computer models suggest that it will soon turn north, slamming the Florida Keys, hugging the west coast of Florida and sparing Metro Miami.  In concert, celebrity reporters and weathermen are racing across the peninsula to be close to the action.

Anyone who has read this blog, even on a casual basis, likely knows that my wife and I own a condo on Longboat Key, off Sarasota.  It now appears that it will incur significant damage but we are fortunate that we have other homes and that none of our family members are currently using that property.  Since purchasing the condo, in 2003, we and our relatives have repeatedly enjoyed Longboat Key with nothing more serious than chilly weather to taint our vacations.

Of course, we always knew that the purchase was a risk and have never believed that public funds should be used to bail out those who choose to occupy barrier islands, river floodplains, volcanic slopes or other high risk zones.  Nature is not cruel but neither is she sentimental; if we do not respect her power or acknowledge the processes that culminated in her beautiful landscapes, we cannot complain when we suffer the consequences.  And when it comes to hurricanes, human-induced global warming will likely make them more frequent and more powerful.


Friday, September 8, 2017

Mexico's Subduction Quake

While the attention of most North Americans has been focused on Hurricane Irma, about to unleash her fury on Florida, a strong earthquake struck off the Pacific Coast of southern Mexico yesterday.  The magnitude 8.2 quake occurred along a subduction zone, where the Cocos Plate (a remnant of the massive Farallon Plate) is dipping beneath the North American Plate; unfortunately, at least 58 persons were killed by the earthquake.

In such subduction zones, the edge of the over-riding plate is pulled down by friction with the subducting plate.  Eventually, this edge rebounds upward, displacing a massive amount of seawater and often triggering a tsunami.  Fortunately, in this case, the latter did not develop.

As the North and South American Plates continue to drift westward in concert with the opening of the Atlantic Ocean, subduction of the Farallon remnants (the Juan de Fuca, Cocos and Nazca Plates, north to south) will continue, igniting volcanic ranges (the Cascades, Mexican volcanoes, Central American volcanoes and the Andes) as they melt and triggering earthquakes offshore that spread across the mainland.

Thursday, September 7, 2017

A Record-Setting Hurricane

Hurricane Irma, churning its way toward Florida, has pulverized a few Caribbean islands along the way.  Since it formed, in the tropical Atlantic, this storm has maintained a symmetrical structure and has not encountered obstacles to its development (wind shear, dry air, cold water or mountain ranges).  As a result, the massive hurricane achieved category 5 status and has retained that strength for more than twice as long as any Atlantic hurricane in recorded history.

Expected to pummel the Turks and Caicos today, the storm's center remained north of Puerto Rico and the Dominican Republic and will likely miss Cuba as Irma continues to track to the WNW.  The Bahamas will soon feel its leading edge and a hurricane warning has now been posted for Southeast Florida and the Florida Keys.

An atmospheric trough to the north, combined with a large dome of high pressure over the mid Atlantic, will eventually steer Irma northward.  When and where it makes that turn will make all the difference to residents of Florida, southern Georgia and the Carolinas.  We should know within 48 hours. 

Wednesday, September 6, 2017

A Pumpkin Moon

Over the last few days, as the waxing moon approached its full stage, our lone natural satellite has taken on an orange hue here in Metro Denver.  Looking like a giant pumpkin, it has hovered over the Eastern Plains in early evening and loomed above the Front Range peaks at sunrise.

The cause for its beautiful yet mysterious appearance is simple.  The moonlight is shining through a smoky haze that has settled across the Colorado Piedmont.  Extensive wildfires in Idaho and Montana are the source of the smoke, which moved southward within an atmospheric trough.  While the latter brought welcome, cooler air to the urban corridor, the smoke has greatly diminished the visibility and has produced a significant health risk for those with pulmonary disease.

While the wildfires continue to burn, winds are expected to shift back to the southwest in the coming days, bringing heat back to the Front Range but clearing out the smoke.  Of course, our pumpkin moon will then lose its colorful tinge.

Tuesday, September 5, 2017

Scrub Jay visits the Farm

Woodhouse's scrub jays are common, permanent residents of the Mountain West, from Nevada to Mexico.  Here along the Colorado Front Range, they are primarily found on the shrublands of the lower foothills and, until yesterday, I had not observed one on our Littleton farm.

While reading at the edge of our driveway, I was startled by the jay as he wandered out from the shrub-lined "lawn," picking at the asphalt in search of food.  After a minute or so, he flew off to our grove of pinyon pines and then headed south.

Like most jays, scrub jays are noisy, aggressive and omnivorous birds; unlike some species, they are usually found alone or in pairs.  They lack the distinctive crest of blue jays (a common permanent resident on the farm) and Steller's jays (an occasional winter visitor here).  Perhaps, like red-breasted nuthatches and lesser goldfinches, they'll become new, year-round residents on our property.

Monday, September 4, 2017

Laborers in America

American laborers generally come from the lower and middle classes; their income is but a small fraction of those in the upper class.  Many laborers have more than one job and few can afford to have their spouse stay home with the kids.  They don't belong to fitness clubs and rarely eat out.

Laborers work at country clubs and resorts but cannot afford to use those facilities.  Some work at professional sports stadiums but could never afford to attend the games.  Laborers avoid toll lanes and reserved parking lots.  They often use mass transit and, while they may load your plane or cruise ship, they could not afford the journey.

Many laborers are guest workers.  They pick our crops, repair our highways, cut our lawns and build our homes.  They take on jobs that more affluent Americans would never consider.  And when they're done, we send them back.  Happy Labor Day!

Sunday, September 3, 2017

September Heat

By September, the longer nights bring chilly mornings to the Front Range cities and, in most years, afternoon highs drop into the 70s F.  In fact, the first snow of the season often dusts the urban corridor before September ends.  This year, however, summer heat is slow to abate.

A ridge of high pressure, the same that blocked Harvey from moving inland, remains in place over the American West.  Deflecting Pacific fronts across the Northern States and blocking the Southwest Monsoon that usually brings rain in August and September, this atmospheric dome is prolonging the summer season and putting the cool, crisp days of autumn on hold.

For those of us who relish the invigoration that autumn brings, this static pattern is less than welcome and may portend a seasonal change that global warming will bring.  Until the jet stream dips across our region, we'll have to rely on migrant songbirds to provide reassurance that the seasons are changing; as in recent years, the waterfowl will likely be in no hurry to come south.  We can only hope that chilly air will arrive in time to spark the glorious colors of October. 

Saturday, September 2, 2017

Rock Wrens

This morning, on my regular birding walk at South Platte Park, I encountered a rock wren, foraging on a spillway.  While these small songbirds are common in canyons and on rock outcrops and boulder fields of the Front Range foothills and mountains, I rarely see them down on the Piedmont.

Found throughout western North America, from southern Canada to Mexico and from the High Plains to the West Coast Ranges, rock wrens are identified by their pale gray coloration (except for a light, rusty wash on their lower abdomen), a long, thin bill, a barred tail and short legs.  Almost always found on rocky slopes or boulder fields, they hunt for insects and spiders, bobbing over the rocks, searching the crevices with their bill or springing into the air to snare their prey.  As one might expect, these vocal birds place their nest within rock crevices, using dried vegetation, sticks and bark chips to build a shallow cup; of interest, they also construct a "patio" of pebbles at the entrance to the crevice.

Come autumn, rock wrens depart the northern half of their summer range (including Colorado), heading for the Central Valley of California, the Desert Southwest or Mexico.  I suspect this morning's visitor at South Platte Park was beginning that biannual trek.

Thursday, August 31, 2017

Detour to the San Juans

Returning to Littleton from Crested Butte, I opted for a detour to the south, covering a stretch of landscape between Gunnison and Creede that I had not previously explored.  Just west of Gunnison, at the east end of the Blue Mesa Reservoir, I turned south on Colorado 149, undulating across sage grasslands that are broken by rocky outcrops.

After dipping through a few creek valleys, the highway makes a significant descent to the Lake Fork of the Gunnison River which it follows upstream.  Hemmed in by cliffs of volcanic sediments, the river rises in the northern San Juans near Lake City.  After passing through that town, Route 149 begins a climb toward Slumgullion Summit, about 11, 600 feet; en route, the road offered a spectacular view of Lake San Cristobal and, at the summit, a broad view of majestic peaks to the northwest.  Unfortunately, bark beetles have decimated the forest in this area (as in many other areas of the San Juans); dipping through pockets of dead and cleared forest, the highway crosses the Continental Divide at Spring Creek Pass (a thousand feet lower than Slumgullion Summit) and begins a winding descent toward the Rio Grand River.

Along the way, an overlook provides a magnificent view of the uppermost Rio Grand Valley, including the Rio Grande Reservoir and Pyramid Peak; the north flank of that mountain has been officially recognized as the source of the Rio Grande.  Paralleling the river just upstream from Creede, Route 149 winds eastward along the Rio Grande all the way to South Fork, Colorado, where it intersects US 160 and the river's southern fork.  Turning east on this highway, I headed toward the San Luis Valley and familiar landscape.

Wednesday, August 30, 2017

Up to Crested Butte

Despite numerous road trips throughout Colorado over the past thirty years, I had yet to visit Crested Butte.  Facing two days with no commitments, I decided to remedy that deficiency and set out from our Littleton farm early this morning; three hours later, I was in Gunnison, enjoying a delicious brunch.

Colorado 135 leads north from Gunnison, crossing the Gunnison River and then following it upstream to Almont, where it rises from the merger of the East and Taylor Rivers.  Before heading to Crested Butte, I drove northeastward on Route 742 through the scenic Taylor River Valley which is quilted with ranches and resorts; numerous pull-offs along the road offer access to the beautiful river, a popular stream for fly-fishing.  About 15 miles from Almont, I reached the spectacular Taylor Park Reservoir, backed by the high peaks of the Sawatch Range.  Returning to Highway 135, I then continued north through the East River Valley which is bordered on the west by the volcanic West Elk Mountains; nearing Crested Butte, the road angles northwest along the Slate River (a tributary of the East), which parallels the base of the Ruby Mountains.

The Old Town area of Crested Butte offers a mix of shops, pubs and cafes while the ski area (Mt. Crested Butte), northeast of town and on the north side of Crested Butte (12,162 feet), has the look and feel of a modern resort.  Before getting some dinner in Old Town, I drove past the ski area and continued northward on Forest Road 317 which yields broad views of the Elk Mountains and of the upper East River Valley at their base.  Throughout the day, I enjoyed the company of mountain bluebirds, Steller's jays, Clark's nutcrackers, pine siskins, magpies and, of course, those vocal subalpine residents, red squirrels.


Sunday, August 27, 2017

Science, Disaster & Denial

Just a few days ago, when Harvey was but a tropical depression in the Western Gulf of Mexico, meteorologists predicted that it would strengthen into a hurricane and then stall along the Texas Coast, causing widespread, disastrous flooding in the region.  No doubt, many in Texas and across the country ignored (and perhaps ridiculed) that forecast.  Unfortunately, the scientists were right.

This week, our anti-science, pro-coal President will likely fly over the extensive flooding; if he sticks to his script, he will express dismay over the tragedy and promise that the Federal Government will provide ongoing assistance.  Once the disaster has resolved, however, he will go back to denying climate change and other inconvenient science-based predictions.

A warming climate will surely increase the incidence of flooding events in coastal regions in addition to its other life-threatening effects across the globe.  Yet, the fossil fuel industry, based in Texas, has long denied the role of human activity (specifically oil, gas and coal consumption) in global warming, contrary to the findings of its own scientists.  No doubt, some evangelical ministers will blame the social tolerance of progressives for this divine retribution and our anti-science, pro-business EPA Director will go on slashing environmental regulations.  The scourge of mysticism will maintain its grip on a large segment of human society, imperiling all life on our planet. 

Saturday, August 26, 2017

Western Heat & Texas Floods

An atmospheric ridge, characterized by a dome of high pressure, currently sits over the Southwestern U.S.  Over the past few days (and for several more to come) sinking air within the dome has pushed afternoon highs near 90 degrees F here in Metro Denver.  In concert, the stagnant high pressure has diverted Pacific storm systems to the north and has cut off the Southwest Monsoon moisture from the south.

This same atmospheric ridge will keep the remnants of Hurricane Harvey along the Texas and Louisiana Coasts, perhaps allowing it to re-strengthen.  Preventing the storm from moving northwestward into the Southern Plains, the high pressure dome will also deprive the Gulf Coast region of Pacific fronts that, under other circumstances, might pull the tropical system into the Midwest and thence to the Mid-Atlantic or New England.

Stuck in place, the remnants of Harvey will drop flooding rains from Corpus Christi to San Antonio and northeastward into Louisiana.  Meanwhile, those of us in the Southwest will have to rely on pop-up showers and thunderstorms to provide relief from the heat and drought.

Thursday, August 24, 2017

Harvey Approaches Texas Coast

Just a tropical depression 36 hours ago, Hurricane Harvey rapidly strengthened over the very warm waters of the western Gulf of Mexico.  Current forecasts indicate that it will strengthen further, perhaps to a Category 3 storm, before making landfall just north of Corpus Christi.

Counter-clockwise winds of 125 mph or more will lash the coast north of the hurricane's center, producing a storm surge of 9 feet or more in some areas.  Of course, wind damage and widespread inland flooding are also expected.

Indeed, the major problem with Hurricane Harvey is that the storm is moving slowly and will not be whisked away by any approaching fronts.  Rather, the hurricane (or its remnant system) is forecast to meander along the Texas Gulf Coast for several days, dumping prodigious amounts of rain on an area that has already experienced a wet spring and summer.  Two feet of precipitation (if not more) will fall in some locations and widespread, severe flooding is almost certain to occur, perhaps as far inland as San Antonio.

Wednesday, August 23, 2017

Bad Habits, Good Genes

Most of us have had friends, family members or acquaintances who, despite unhealthy habits (smoking, heavy alcohol consumption, a junk-food diet and a lack of aerobic exercise) live long, disease-free lives; having practiced medicine for forty years, I encountered many such individuals.  Of course, these persons were saved by a genetic allotment that prevented the consequences of their careless behavior.

Exposure to such individuals tends to make the rest of us fate-oriented and may convince us to abandon efforts to maintain a healthy lifestyle; when one's parents lived to an advanced age despite bad habits, the delusion is especially powerful.  However, we each have our own, unique set of genes and until such time that genetic screening is widely available at a reasonable cost (and completely understood by the medical community), it is wise to cut your risk by adhering to healthy life choices.  Counting on your genes to protect you is just a game of chance.

Finally, most of us will face serious health issues in the course of our lives and the effort to remain active and healthy beforehand will significantly improve our ability to survive such insults, whether they be accidents or illnesses.  We can't change our genes (at least not yet) but we can try to prevent disease by avoiding toxic behaviors, ingesting a healthy diet, engaging in regular aerobic activity and adhering to appropriate screening recommendations.

Tuesday, August 22, 2017

Scotts Bluff

Returning to Colorado after the solar eclipse, I angled southwestward to Scotts Bluff, Nebraska, in an effort to escape the heavy traffic.  While that plan failed miserably, I was able to view Scotts Bluff itself, protected in a National Monument since 1919.  This massive erosional remnant rises up to 800 feet above the North Platte River, which sculpted most of its broad valley over the past 5 million years.

During the Cretaceous Period, some 100 million years ago, a shallow sea covered most of the High Plains region, leaving behind shale and sandstone as the Rockies rose and the sea retreated.  In concert, the mountains eroded as fast as they rose and sheets of sediments were spread across the adjacent plains; volcanic debris also blew in from the San Juans of southwest Colorado.  Periods of uplift, especially in the Miocene and Pliocene, intensified the erosion and fed large, meandering rivers.  Today, Scotts Bluff, like the cliffs along the edge of the North Platte Valley, is a testimonial to that natural history; it is a layer-cake of sedimentary rocks deposited during the Oligocene and Miocene Periods, some 34 to 20 million years ago.

Named for Hiram Scott, a fur trapper who died in this area in 1828 (at the age of 23), Scotts Bluff has long been an important landmark, both for Native Americans and for settlers who traveled west on the Oregon, Mormon and California Trails.  I would have visited the Monument myself but I had eight hours of stop-and-go traffic ahead of me.

Monday, August 21, 2017

Totality!

As I left Denver this morning, a magenta sunrise spread across the eastern horizon; I wondered if the solar eclipse would match the beauty of that brilliant display.  Heading northeastward along Interstate 76, I crossed the rolling grasslands of the High Plains, adorned in late summer by swaths of prairie sunflowers.  Near Wiggins, the highway drops into the valley of the South Platte River, often shrouded in a dusky fog during the early morning hours.

I exited the Interstate in a pea-soup fog at Sterling, Colorado, and headed north on Route 113, climbing from the valley and re-entering the bright sunshine; wind turbines lined the crest of the escarpment, east and west of Peetz.  Farther north, I crossed Interstate 80 at Sidney, Nebraska, and continued northward on US 385, dipping through the North Platte River valley at Bridgeport, where the first eclipse-watching celebrations lined the roadway.  South of Alliance, I cut westward on a graveled road, finally escaping the parade of vehicles that had accompanied me all the way from Denver.

Choosing a location along a wooded ridge, I waited for the big event; the skies were clear except for a few high cirrus clouds.  A north wind raked the ridge and a loggerhead shrike provided company, hunting along a fence line.  About fifteen minutes before totality, a faint darkness began to envelop the landscape, suggesting the onset of dusk; the rate of darkening increased until totality occurred, when the sun's corona produced a brilliant ring around the edge of the moon's dark disc.  While the total solar eclipse was spectacular (and well worth my five hour journey), it was the sudden return of brilliant sunshine, shattering the darkness, that, for me, produced the emotional highlight of this celestial event.

Sunday, August 20, 2017

North to the Darkness

Tomorrow, I plan to head north to view the solar eclipse.  My current plan is to drive northeastward to Sterling, Colorado, then northward to Sidney, Nebraska, and then farther north to somewhere in the North Platte Valley to experience the spectacle.

While I look forward to the event and hope that clear skies enhance nature's show, I must admit that we Americans seem to be over-reacting to an astronomical convergence, one that happens somewhere on our planet every 18 months or so.  For scientists, the eclipse will provide a unique opportunity to study the sun's corona but, for most of us, it will be more of an emotional event; no doubt, some will ascribe mythical significance to this transient phenomenon.

Whether I actually reach the zone of totality or not, I'll enjoy the road trip which will take me across the stark landscape and grassland ecosystems of the High Plains.  More on the entire experience tomorrow evening.

Wednesday, August 16, 2017

Prickly Lettuce in Bloom

Favoring sunny areas and dry soil, prickly lettuce is one of the most abundant wildflowers (some would say weeds) along the Colorado Front Range.  This week, those on our Littleton farm are blooming, their numerous, small, pale-yellow flowers adorning the landscape.

One of many wild lettuces across the globe, this wildflower is also closely related to dandelions and, like the latter, is an introduced native of Eurasia.  Despised by gardeners, this tall plant has prickly, deeply-lobed leaves that alternate sides along the branched stems; since the leaves twist to face the sun, prickly lettuce is also known as the compass plant.  Like dandelions, the leaves and flowers of this wildflower are edible but the milky sap, used for a variety of medicinal purposes, produces a bitter taste and the foliage must be properly cleaned before consumption (not my area of expertise).

Having yanked many stalks of prickly lettuce from our flower beds and shrub lines over the years, I understand those who prefer to call it a noxious weed.  But when the plant blooms (anytime from July to October), it is an attractive wildflower in my book.