Two years ago I shared my first collection of urban botanical art photos. Since that time I have collected several more. I had hoped to get lots of photos during my trips out of town, and while I did manage to get a few, it turns out that my hometown of Boise, Idaho has a sizable (and growing) selection of plant-related public art. Thus, several of these are local finds.
This is a guest post by Martha Dalke Hindman. It is an excerpt from her upcoming book, The Dragon of Yankee Fork.
July through September, river water is low, cold, clear.
Four huge, round washbasins appear in an ageless,
Rectangular, horizontal piece of white granite rock.
“Devil’s Washbasins,” at Selway Falls.
Cousin to the domestic Raspberry,
Thimbleberries grow along the river bank.
White blossoms, no thorns, broad indented leaves,
Red berries, a bit of sugar, delectable desert.
Long shadows on the dusty, winding road, from Race Creek to Selway Falls, made driving a challenge. Kaye and I stopped at Selway Falls to rest and look into “The Devil’s Washbasins.” Although the Falls are not particularly high, only 25 feet, the sound of the water cascading over timeless, granite boulders, into the river below, creates a world unto itself.
A cream colored car with Oregon license plates slowed to a stop. A man and woman stepped out. I smiled and asked if I could be of assistance.
“Can you tell us WHERE Selway Falls is,” the gentleman asked. “There is no marker.”
“Selway Falls is right here,” I explained. “Do you hear the rushing, tumbling water?”
“But, but! That is just a pile of rocks!!” The gentleman exclaimed. “We expected to see falls like Multnomah Falls near Portland, Oregon.”
“I am sorry you are so disappointed.” I said. I explained that waterfalls the height and size of Multnomah are not found in this particular part of the country. “If you care to stop at Fenn Ranger Station, I am sure the ranger on duty can give you more detailed information about the falls. You will see a large sign reading, ‘Fenn Ranger Station, Nez Perce National Forest’, as you return to the blacktop portion of the road.”
Thoroughly disillusioned and disgusted, the couple returned to their car and drove away in a cloud of dust!
“Devil’s Washbasins” is this author’s name for four giant bowls in white Granite rock at the bottom of Selway Falls on the Selway River, Nez Perce-Clearwater National Forest. The bowls created by centuries of water, can only be observed when the river water is low, usually after the 4th of July and until snow covers the forest. Observe the calm pool at the top of the falls. Enjoy the water’s music and beauty. Help to preserve its Integrity.
“Selway Falls technically is not a falls. It is called a ‘cataract.’ This occurred when the North side of the mountain slid into the river. The flow of the water found ways to continue its journey to the sea. Small pools formed, the water moved around boulders 30 feet in diameter, as well as over and under downed trees, submerged logs, smaller rocks and debris. The water level fluctuates from 23 feet to 32 feet, dependent upon the winter’s snowpack in the mountains and the spring run off.“ [Columbia River Fisheries Development Program, February 1, 1967, STATE OF IDAHO, Fish and Game Department, John R. Woodworth, Director. Pages not numbered.]
A FOREST CHASM
I looked into the Chasm
Of Selway Falls
Late one Summer afternoon.
Four irregular washbasins
In one piece of Granite
Basked In the Summer Sun
The Seasons to change
Fall, Winter, Spring.
Who comes to drink
From these four washbasins?
Only the River
And the forest
We humans can
- Print: Selway District Recreation Guide, United States Department of Agriculture, Forest Service, Nez Perce National Forest, G.P.O 793-552.
- Online: Nez Perce-Clearwater National Forests – Selway River Corridor
Poetry, personal stories, images, journal entries, recipes for Springerle, Cinnamon Rolls, Fried Cakes, “a little bit of science thrown in for good measure,” print and online resources, all define “The Dragon of Yankee Fork,” an Idaho Alphabet from A to Z. It all began on a long piece of cream colored shelf paper! (Visit the Go Fund Me page to learn more about the project and contribute to its creation.)
Martha Dalke Hindman’s outdoor classroom was the travel adventures she shared with her father around the State of Idaho. From dusty roads, fishing expeditions, and a keen sense of observation, learning about Idaho’s Heritage gave Ms. Hindman her voice in poetry and personal short stories. She may be reached at martha20022 [at] gmail [dot] com.
Some weeds are so noxious, their crimes so heinous, and their control so challenging that desperation leads us to introduce other non-native organisms to contain them. Alien vs. alien duking it out in a novel environment. It seems counterintuitive – if an introduced species has reached the status of invasive, is it worth the risk of bringing in yet another foreign species in attempt to defeat it? We all know what happened to the old lady who swallowed the spider to catch the fly, yet for decades now we have been doing just this. It’s something we call classical biological control – introducing pathogens, insects, or other organisms to help control the spread of problematic ones.
Such attempts mostly fail, but we keep trying. The attempts made on Cirsium arvense exemplify this. The trouble is that even when such efforts fail, they aren’t always benign, as we shall see.
Canada thistle, a misnomer for Cirsium arvense, is a European native that has been acting in the role of noxious weed for centuries, even in its native land. First introduced accidentally to eastern North America sometime in the 1600’s, it has made its way across the continent and has since become one of our worst weeds in both natural and agricultural settings, as well as in our yards and gardens. Its seeds get around, carried by wind and water, attached to animals or deposited in their dung, stowing away as contaminants in crop seed or passengers in the ballast water of ships. But casual dispersal by seed isn’t quite as troubling as what it does once it takes root.
Several related species of thistle are also pesky weeds, but unlike Cirsium arvense, they are mostly annuals or biennials, spreading only by seed. Cirsium arvense is a perennial plant with roots that spread deep and wide. New shoots form readily along the spreading roots, forming a veritable thicket of stems that can be dozens of feet wide and giving the plant a more appropriate common name, creeping thistle.
The stems of creeping thistle can grow more than four feet tall and are adorned with alternately arranged, prickly, lobed leaves. Groups of small, urn-shaped flowerheads are born at the tops of stems. Flowers are pink to purple, sweet smelling, and favored by pollinators. Individual plants either produce all male flowers or all female flowers, and since individual plants are actually large colonies, an adjacent colony of the opposite sex is necessary in order for the production of viable seeds. Like other plants in the aster family, the seeds come with a feathery pappus, suggesting wind dispersal. However, the pappus is often weakly attached, sloughing off without seeds in tow, leaving them to the fate of gravity.
It comes as no surprise that when plants readily spread by root, stolon, or rhizome, they are well suited to become some of our most bothersome weeds. Eliminating their seed heads does little to reduce their spread. Pulling them out of the ground is futile; you will never get all the roots. Tilling them under only aids in their dispersal since chopped up roots and stems now have the chance to produce new plants. Herbicide treatments can set them back, but they must be repeated on a long-term and exacting schedule in order to thoroughly kill the roots. Considering what we’re up against when it comes to plants like creeping thistle, it makes sense why we would introduce foreign fighters to do our bidding, especially if such fighters are enemies of the plant in their native land.
The list of insects that have been employed (or at least considered) in the fight against creeping thistle is extensive. It includes thistle tortoise beetle (Cassida rubiginosa), seedhead weevil (Rhinocyllus conicus), thistle crown weevil (Trichosirocalus horridus), thistle gall fly (Urophora cardui), thistle stem weevil (Ceutorhynchus litura), thistle bud weevil (Larinus planus), seedhead fly (Orellia ruficauda), thistle flea beetle (Altica carduorum), thistle leaf beetle (Lema cyanella), painted lady (Vanessa cardui), and sluggish weevil (Cleonus piger). Unfortunately, and perhaps not surprisingly, as Bugwood reports, “biocontrol currently provides little or no control of Canada thistle populations, although some agents weaken and kill individual plants.” Despite the fact that there are well over 100 known organisms that consume or attack Cirsium arvense, nothing manages to do long-term damage.
The status of creeping thistle biocontrol efforts on two South Dakota wildlife refuges was reported on in a 2006 issue of Natural Areas Journal. Multiple introductions of at least half a dozen different insect species had occurred beginning in 1986. Nearly 20 years later, they were not found to have had a significant effect on creeping thistle populations. The authors concluded stating they “do not advocate further releases or distribution in the northern Great Plains of the agents” examined in their study. They also advised that “effectiveness be a primary consideration” of any new biocontrol agents and expressed concern that some introduced insects have the potential to attack native thistles.
North America is home to quite a few native thistles, several of which are rare or threatened. A USDA guide to managing creeping thistle in the Southwest highlights the importance of protecting native thistles – “especially rare or endangered species” – from biocontrol agents and gives two examples of endangered thistles in New Mexico that are at risk of such agents.
The federally threatened species, Pitcher’s thistle (Cirsium pitcheri), which is restricted to sand dune shorelines along the upper Great Lakes, has quite a bit working against it. An added blow came a few years ago when it was discovered that the flowerheads of Pitcher’s thistle were being damaged by the thistle bud weevil (Larinus planus), a biocontrol agent employed against creeping thistle in the area. A paper published in Biological Conservation in 2012 examining the extent of weevil damage on the rare thistle cautioned that, “although some biological control agents may benefit some rare plant taxa, the negative impacts of both native insects and introduced herbivores are well documented.”
Classical biological control, if and when it works, can be quite valuable, especially if it reduces the need for other management inputs like herbicides and cultivation. Unfortunately, it is rarely successful and can have unintended consequences. Goldson et al. report in a 2014 issue of Biological Conservation that the success rate is only around 10% and that even that 10% is at risk of failing at some point. In his book, Where Do Camels Belong?, ecologist Ken Thompson cites that “only about one in three species introduced as biological controls establish at all, and only half of those that do establish (i.e. about 16% of total attempts) control the intended enemy,” adding that “biological control is just another invasion, albeit one we are trying to encourage rather than prevent, and its frequent failure is another example of how poorly we understand the effects of adding new species to ecosystems.”
Still, while some warn against being too optimistic, others argue that it is an essential tool in the war against invasive species and, while acknowledging that a few introductions have gone awry, assert that “significant non-target impacts” are rare. Clearly, this is a rich topic ripe for healthy debate and one that I will continue to explore. If you have thoughts or resources you’d like to share, please do so in the comment section below.
Last week, we found ourselves in Vancouver, British Columbia for a work-related conference put on by American Public Gardens Association. In addition to learning heaps about plant collections and (among other things) the record keeping involved in maintaining such collections, we got a chance to visit two Vancouver botanical gardens. Both gardens were pretty big, so covering the entire area in the pace we generally like to go in the time that was allotted was simply not possible. Still, we were smitten by what we were able to see and would happily return given the chance. What follows are a few photos from each of the gardens.
UBC Botanical Garden
UBC Botanical Garden is located at the University of British Columbia. Established in 1916, it is Canada’s oldest university botanical garden. We saw a small fraction of the Asian Garden, which is expansive, and instead spent most of our time in other areas, including the Alpine Garden, the Carolinian Forest Garden, the Food Garden, and one of my favorite spots, the BC Rainforest Garden. The Rainforest Garden is a collection of plants native to British Columbia, which was the original focus of UBC Botanical Garden’s first director, John Davidson.
VanDusen Botanical Garden
VanDusen Botanical Garden is a 55 acre garden that opened in 1975 and is located on land that was once a golf course. It features an extensive collection of plants from around the world accompanied by a series of lakes and ponds as well as lots of other interesting features (like a Scottish Shelter, a Korean Pavilion, an Elizabethan Maze, and more). Our time there was far too brief. The whirlwind tour we joined, led by the education director, was a lot of fun, and if the threat of missing our bus wasn’t looming, we would have been happy to stay much longer.
More Awkward Botany Field Trips:
When a flower blooms, a celebration is in order. Flowers abound for much of the year, which means parties are called for pretty much non-stop (something Andrew W.K. would surely endorse). Since we can’t possibly celebrate every bloom, there are certain plants we have decided to pay more attention to – plants whose flowers aren’t so prolific, predictable, or long-lived; or plants whose flowers come infrequently or at odd times of the day (or night).
This is the case with the flowers of the night blooming cactus, Epiphyllum oxypetalum, which goes by many names including Dutchman’s pipe cactus, queen of the night, orchid cactus, night blooming cereus, and tan hua. Tan hua is the Chinese name for the plant, and this is how it is referred to in the book, Crazy Rich Asians by Kevin Kwan.
In the book, Nick Young brings his American girlfriend, Rachel Chu, to meet his ridiculously wealthy family in Singapore. Before the trip, Rachel was in the dark about the Young’s wealth. She first meets the family and their gargantuan mansion when Nick’s grandma, seeing that her tan hua flowers are about to bloom, throws an impromptu (and lavish) party. Nick refers to the flowers as “very rare,” blooming “extremely infrequently,” and “quite something to witness.”
In a seperate conversation, Nick’s cousin, Astrid, tries to convince her husband to attend the party by claiming, “it’s awfully good luck to see the flowers bloom.” Later, another one of Nick’s cousins tells Rachel, “it’s considered to be very auspicious to witness tan huas blooming.”
Native to Mexico and Guatemala, E. oxypetalum was first brought to China in the 1600’s. Its beauty and intrigue along with its relative ease of cultivation helped it become popular and widespread across Asia and other parts of the world. Watching it bloom is considered a sacred experience by many, including in India, where it is said to bring luck and prosperity to households who are fortunate enough to see theirs bloom.
Epiphyllums are epiphytic, meaning they grow non-parasitically on the surfaces of other plants, such as in the crevices of bark or the crotches of branches. Like other cacti, they are essentially leafless, but their stems are broad, flat, and leaf-like in appearance. Showy, fragrant flowers are born along the margins of stems. The flowers of tan hua, as described in Crazy Rich Asians, appear as “pale reddish petals curled tightly like delicate fingers grasping a silken white peach.” A report (accompanied by photos) published by Sacred Heart University describes watching tan hua flowers progess from bud formation to full bloom, a process that took more than two weeks.
Tan huas are certainly not rare, as Nick described them. A number of Epiphyllum species and their hybrids are commonly cultivated; there is even an Epiphyllum Trail at San Diego Zoo’s Safari Park. Listed as “least concern” on the IUCN Red List, their popularity as ornamentals is noted but is not seen as affecting wild populations. Night blooming plants, while fascinating, aren’t all that rare either. Such plants have adapted relationships with creatures, like bats and moths, that are active during the night, employing their assistance with pollination. A paper published in Plant Systematics and Evolution describes the floral characteristics of Epiphyllum and similar genera: “The hawkmoth-flower syndrome, consisting of strongly-scented, night-blooming flowers with white or whitish perianths and long slender nectar-containing floral tubes is present in Cereus, Trichocereus, Selenicereus, Discocactus, Epiphyllum, and a number of other cactus genera.”
That being said, the specialness of a short-lived, infrequent, night blooming flower should not be understated, and really, parties being thrown in honor of any plant are something I can certainly get behind. Sitting in the courtyard late at night, the Young family and their guests watched as “the tightly rolled petals of the tan huas unfurled like a slow-motion movie to reveal a profusion of feathery white petals that kept expanding into an explosive sunburst pattern.” The look of it reminds Astrid of “a swan ruffling its wings, about to take flight.”
Later, “the tan huas began to wilt just as swiftly and mysteriously as they had bloomed, filling the night air with an intoxicating scent as they shriveled into spent lifeless petals.”
- African Journal of Agriculture Research: Optimal conditions for germination of seeds of Epiphyllum oxypetalum
- International Journal of Pharmacy and Pharmaceutical Sciences: Assessment of Nutritive Values, Phytochemical Constituents and Biotherapeutic Potentials of Epiphyllum oxypetalum
- SF Gate: Growing Epiphytic Cactuses
*Thank you Kathy for letting me borrow your Kindle so that I could write this post.
In this special edition of Awkward Botanical Sketches, I took some inspiration from a book called Dear Data by Giorgia Lupi and Stefanie Posavec. In this book, two friends separated by an ocean chose something about their lives to collect data on every week for a year, then they exchanged the data they collected via weekly postcards. They did this by drawing out a representation of their data on the front of the postcard, along with a key to the drawing on the back. It seemed like a fun thing to do, so I decided to try it. Rather than mailing my postcards to someone across the sea, I am sharing them here.
My ability to creatively present the data I collected pales in comparison to Lupi and Posavec, but I had fun giving it a shot. Most importantly, it satisfied my quest to draw more. This first postcard is all about the weeds I came across in a week.
Whenever I listen to music I make a mental note of any botanical references made in the lyrics. I generally don’t do anything with these mental notes – unless, of course, I’m writing something about them (see this Botany in Popular Culture post, for example) – but this time I did. Saturday was a particularly busy day because I was listening to a lot of Ghost Mice.
My obvious obssesion with weeds and my intention to write a weeds-themed book someday – plus my career as a horticulturist – means that I frequently find myself involved in activities and conversations involving weeds. I wasn’t exactly sure how to track that, so this is my lousy attempt at doing so. In case you’re wondering what I was up to on Saturday (the big, blue circle), this tweet and Instagram post should help explain things.
Further Reading: Review of Dear Data in The Guardian
Crab spiders that hunt in flowers prey on pollinating insects. Thus, pollinating insects tend to avoid flowers that harbor crab spiders. We established this in part one. Now we ask, what effect, if any, does this interaction have on a crab spider infested plant’s ability to reproduce? More importantly, what are the evolutionary implications of this relationship?
In a study published in Ecological Entomology earlier this year, Gavini, et al. found that pollinating insects avoided the flowers of Peruvian lily (Alstroemeria aurea) when artificial spiders of various colors and sizes were placed in them. Bumblebees and other bees were the most frequent visitors to the flowers and were also the group “most affected by the presence of artificial spiders, decreasing the number of flowers visited and time spent in the inflorescences.” This avoidance had a notable effect on plant reproduction, namely a 25% reduction in seed set and a 15% reduction in fruit weight. The most abundant and effective pollinator, the buff-tailed bumblebee, was deterred by the spiders, leading the researchers to conclude that, “changes in pollinator behavior may translate into changes in plant fitness when ambush predators alter the behavior of the most effective pollinators.”
But missing from this discussion is the fact that crab spiders don’t only eat pollinators. Any flower visiting insect may become a crab spider’s prey, and that includes florivores. In which case, crab spiders can benefit a plant, saving it from reproduction losses by eating insects that eat flowers.
In April of this year, Nature Communications published a study by Knauer, et al. that examined the trade-off that occurs when crab spiders are preying on both pollinators and florivores. Four populations of buckler-mustard (Biscutella laevigata ssp. laevigata) were selected for this study. Bees are buckler-mustard’s main pollinator, and in concurrence with other studies, they significantly avoided flowers when crab spiders were present. Knauer, et al. also determined that bees and crab spiders are attracted to the same floral scent compound, β-ocimene. This compound not only attracts pollinators, but is also emitted when plants experience herbivory, possibly to attract predators to come and prey on whatever is eating them.
In this study, the predators called upon were crab spiders. Florivores had a notable impact on plants in this study, and the researchers found that when crab spiders were present, florivores were significantly reduced, thereby reducing their negative impact. They also noted that “crab spiders showed a significant preference for [florivore-infested] plants over control plants.”
And so it is, a plant’s floral scent compound attracts pollinators while simultaneously attracting the pollinator’s enemy, who is also called in to protect the flower from being eaten. Luckily, in this case, buckler-mustard is easily pollinated, so the loss of a few pollinators isn’t likely to have a strong negative effect on reproduction. As the authors write, “pollinators are usually abundant and the low number of ovules per flower makes a few pollen grains sufficient for a full seed set.”
But none of these studies are one size fits all. Predator-pollinator-plant interactions are still not well understood, and there is much to learn through future research. A meta-analysis published in the Journal of Animal Ecology in 2011 looked at the research that had been done up to that point. Included were a range of studies involving sit-and-wait predators (like crab spiders and lizards) as well as active hunters (like birds and ants) and the effects of predation on both pollinators and plant-eating insects. They concluded that where carnivores “disrupted plant-pollinator interactions, plant fitness was reduced by 17%,” but thanks to predation of herbivores, carnivores helped increase plant fitness by 51%. This suggests that carnivores, overall, have a net positive effect on plant fitness.
Many pollinating insects have an advantage over plant-eating insects because they move quickly from flower to flower and plant to plant, unlike many herbivores which move more slowly. This protects pollinators from predation and helps explain why plant-pollinator interactions are not disrupted as easily by carnivores. Additionally, as the authors note, “plants may be buffered against loss of pollination by attracting different types of pollinators, some of which are inaccessible to carnivores.”
But again, there is still so much to discover about these complex interactions. One way to gain a better understanding is to investigate the effects of predators on both pollinators and herbivores in the same study, since many of the papers included in the meta-analysis focused on only one or the other. As far as crab spiders go, Knauer, et al. highlight their importance in such studies. There are so many different species of crab spiders, and they are commonly found on flowers around the globe, so “their impact on plant evolution may be widespread among angiosperms.”
In other words, while we still have a lot to learn, the impact these tiny but skillful hunters have should not be underestimated.