If you live in a major city (or even a minor one), there is a good chance it is home to a college or university (perhaps several). Universities tend to take up a lot of space, which means there is often a plethora of landscaping accompanying their buildings, hardscaping, and other impervious surfaces. Among all the turf, flower beds, tree wells, and other greenspaces, there is bound to be a fair share of weeds. In spite of how hard the groundskeepers may work, the campus is not likely to ever be completely weed-free. Lucky for us, this means that institutions of higher learning are excellent places to familiarize ourselves with many of the weed species that occur in our cities, particularly weeds that are common in garden beds and turfgrass.
Near downtown Boise, on the southside of the Boise River, you will find the ever-expanding campus of Boise State University, home of the Broncos and their famous blue turf. According to the internet’s favorite encyclopedia, the campus is 285 acres in size, plenty of space for weeds to grow and abudant opportunities to hunt them out. Tallying the number of weed species in a place like this takes time. The benefit of botanizing for weeds is that you can find them at just about any time of year. While some species only show up in certain seasons, others can be seen practically year-round.
In order to document the weeds of Boise State University, I’m spending the entire year walking the campus listing and photographing the weeds I find. What follows is the first half of what’s been documented so far. I’m including a photograph for each month of the year, as well as a list of what I’ve encountered. In part two, I’ll share a list of any additional weeds found throughout the remainder of the year. While you’re waiting for that, check out the other posts in the Weeds of Boise series.
common groundsel (Seneciovulgaris) at BSU in January 2023
chickweed (Stellaria media) at BSU in February 2023
hairy bittercress (Cardamine hirsuta) at BSU in March 2023
ivyleaf speedwell (Veronica hederifolia) at BSU in April 2023
black medic (Medicago lupulina) at BSU in May 2023
creeping thistle (Cirsium arvense) at BSU in June 2023
List of weeds found on the campus of Boise State University as of June 2023:
Ailanthus altissima (tree of heaven)
Anthriscus caucalis (bur chervil)
Amaranthus retroflexus (redroot pigweed)
Arctium minus (lesser burdock)
Bassia scoparia (kochia)
Bromus tectorum (cheatgrass)
Capsella bursa-pastoris (shepherd’s purse)
Cardamine hirsuta (hairy bittercress)
Ceratocephala testiculata (bur buttercup)
Chenopodium album (lamb’s quarters)
Chondrilla juncea (rush skeletonweed)
Cirsium arvense (creeping thistle)
Claytonia perfoliata (miner’s lettuce)
Convolvulus arvensis (field bindweed)
Conyza canadensis (horseweed)
Descurainia sophia (flixweed)
Digitaria sanguinalis (crabgrass)
Draba verna (spring draba)
Epilobium ciliatum (willowherb)
Erodium cicutarium (redstem filare)
Euphorbia maculata (spotted spurge)
Galium aparine (cleavers)
Geum urbanum (herb Bennet)
Holosteum umbellatum (jagged chickweed)
Hordeum jubatum (foxtail barley)
Lactuca serriola (prickly lettuce)
Lamium purpureum (purple deadnettle)
Lepidium sp. (whitetop)
Malva neglecta (common mallow)
Medicago lupulina (black medic)
Oxalis corniculata (creeping woodsorrel)
Parthenocissus quinquefolia (Virginia creeper)
Plantago lanceolata (narrowleaf plantain)
Plantago major (broadleaf plantain)
Poa annua (annua bluegrass)
Poa bulbosa (bulbous bluegrass)
Polygonum aviculare (prostrate knotweed)
Portulaca oleracea (purslane)
Prunella vulgaris (self-heal)
Ranunculus repens (creeping buttercup)
Senecio vulgaris (common groundsel)
Sonchus sp. (sow thistle)
Stellaria media (chickweed)
Taraxacum officinale (dandelion)
Tragopogon dubius (salsify)
Trifolium repens (white clover)
Ulmus pumila (Siberian elm)
Veronica hederifolia (ivyleaf speedwell)
Vulpia myuros (rat’s tail fescue)
Do you frequent the BSU campus? Have you seen anything not on my list? Comment below or send me a message and let me know what you’ve seen and where.
Urban areas are increasingly being studied for their potential to help conserve biodiversity and provide habitat for numerous plants and animals. Despite the harsh conditions of the built environment, organisms of all kinds are able to survive in our cities, and as we find ways to make these spaces more hospitable for them, cities actually have great potential for species conservation, even for species that are rare, threatened, or specialized. One obvious way to accomplish this is to manage our yards, parks, and gardens as habitat, such as planting flower strips for pollinators. Another way, perhaps overlooked at times, is to manage and maintain vacant lots as habitat. Every urban area has some degree of vacant land that for one reason or another has not been developed, or that once was developed but has since been bulldozed or abandoned. Spontaneous vegetation quickly moves in to occupy these sites, and while some may see them as eyesores, their potential for providing habitat for an untold number of plants and animals is substantial.
In cities that are growing – like Boise, Idaho – vacant and abandoned lots are disappearing quickly as development strives to keep up with population growth. My first Weeds of Boise post took place at an abandoned Pizza Hut, which has since been demolished and is now the future site of a large building (see photo below). This is happening all over the city – the City of Trees is looking more like the City of Cranes these days. On the other hand, cities that are shrinking due to economic downturn, loss of industry, and other factors, have an increasing number of vacant lots, which offers the opportunity not only to maintain these lots as habitat, but also to carry out research that will help us understand how these locations can be best managed for species conservation.
Abandoned Pizza Hut Lot Now Under Construction
Cleveland, Ohio is one example of a “shrinking city.” Due to significant population decline, Cleveland has a growing number of vacant lots, many of which are maintained by the City of Cleveland Land Bank. For researchers at The Ohio State University, all of this vacant land presents an opportunity to study, among other things, urban biodiversity. Hence, the Cleveland Pocket Prairie Project was born. By assigning different management treatments to groups of vacant lots and observing the differences between each treatment, researchers can help determine the best strategies for managing vacant lots, particularly when it comes to biological conservation. One of the major focuses of the Cleveland Pocket Prairie Project is to determine how vacant land can provide habitat for insects and other arthropods.
In a study published in Sustainability (2018), researchers in Cleveland compared the species richness and abundance of bees found on vacant lots to those found on urban farms. Bee collections were made three times a year over a three year period. Of the more 2733 bees collected, researchers identified 98 total species representing 5 different families. The vast majority of the species were native to the area. Significantly more bees were found in vacant lots compared to urban farms. In both vacant lots and urban farms, the total number of ground nesting bees decreased as the proportion of impervious surfaces near the study sites increased. Plants that received the most bee visits on the urban farms during the study period were common milkweed (Asclepias syriaca), chives (Allium schoenoprasum), and squash (Cucurbita pepo); while the top three plants with the most bee visits on vacant lots were red clover (Trifolium pratense), white clover (Trifolium repens), and Queen Anne’s lace (Daucus carota).
Bee communities differed between vacant lots and urban farms: 29 of the 98 total species were seen only in vacant lots, while 14 species were seen only at urban farms. Most of the bees collected in this study were ground nesting species, and researchers suspect the reason more bees were found on vacant lots compared to urban farms is that farms experience frequent soil disturbance in the form of tillage, weeding, mulching, and irrigation, while vacant lots generally do not. The researchers conclude that their study “adds to the growing body of literature advocating for the maintenance of minimally-managed vacant lot habitats as a conservation resource.” Vacant land that is “surrounded locally by high concentrations of impervious surface,” however, may not be the most suitable location to carry out conservation efforts.
In a study published in Urban Ecosystems (2020), researchers in Cleveland looked at the species richness and abundance of lady beetles in vacant lots. They were particularly interested in the potential that vacant lots may have in providing habitat for lady beetles that are native to the region. The study consisted of 32 vacant lots, each assigned one of four habitat treatments: control (seeded with turfgrass and mowed monthly), meadow (seeded with turfgrass and mowed annually), low-diversity prairie (seeded with three species of prairie grasses and four species of native prairie forbs), and high-diversity prairie (seeded with three species of prairie grasses and sixteen species of native prairie forbs). The two prairie treatments were mown annually. The majority of the nearly 3000 lady beetles captured across all of the plots over a two-year study period were exotic (introduced) species. Sixteen species total were collected: four exotic and twelve native.
The researchers predicted that the lots seeded with prairie plants native to the region would support a higher abundance of native lady beetles than those composed of turfgrass, especially those that are frequently mown. Surprisingly, a similar abundance and species richness of both native and exotic lady beetles were found across all treatments. What appeared to be important for native lady beetle abundance were vegetation features like bloom abundance, height, and biomass. The surrounding environment also matters. As the researchers put it, “vacant lots embedded in landscapes dominated by impervious surface and with a high degree of habitat isolation were less suitable habitats” – a similar conclusion to that made in the bee study.
The most abundant native lady beetle collected in the study was the ursine spurleg lady beetle (Brachiacantha ursina). The larvae of this beetle “infiltrate the nests of Lasius ants,” which is “one of the most common genera of ants found in urban environments.” Researchers posit that the abundance of B. ursina reflects the habitat preferences of ants in the Lasius genus. Several species of lady beetles native to the region are experiencing significant population declines, and the researchers were disappointed to find that none of the most rare species were collected during their study period. However, it was promising to find that “pollen and nectar provided by both seeded native and naturally occurring weedy plants” appeared to be important food sources for native lady beetles.
Both studies indicate that vacant lots can be important locations for habitat conservation in urban areas, particularly when they are part of a larger collection of greenspaces. In combination with managing our yards, parks, and urban farms as quality habitat for plants and animals, conserving vacant lots that consist of diverse vegetation (both planted and spontaneous) can help support insect populations within our cities.
Growing plants in urban areas comes with a variety of challenges. Soil conditions aren’t always ideal; shade thrown by buildings and other structures can be difficult to work around; paved surfaces lead to compaction and, among other things, can increase temperatures in the immediate area; and in locations where water is limited, keeping plants hydrated is a constant concern. One location that tends to be especially difficult for gardeners is the hellstrip – the section of ground between a roadway and a sidewalk. Much can be said about gardening in hellstrips, so much that there is even a book about it called Hellstrip Gardening by Evelyn Hadden, which I spent several posts reviewing a few years back.
The difficulty of maintaining a hellstrip (and perhaps questions about who is responsible for maintaining it in the first place) can result in it being a piece of property frequently subject to neglect. In urban areas, neglected land is the perfect place for weeds to take up residence. The conditions in a hellstrip being what they are – hot, dry, frequently trampled, and often polluted – also gives weeds a chance to show what they can do. It’s a wonder that any plant can survive in such conditions, but the wild flora of our cities consists of some pretty tough plants, and a hellstrip is an excellent location to familiarize yourself with some of these plants.
On a walk with Kōura, I came across a weedy hellstrip on Jefferson Street in downtown Boise. Many of the classic hellstrip challenges are present there – it’s surrounded by paved surfaces, there is lots of foot traffic in the area, parking is permitted on the roadside, urban infrastructure (street signs, parking meters, stoplights) is present within the strip. It’s clear that at one point the area was being maintained as irrigation is installed and there are remnants of turfgrass. Three honey locusts were also planted in the strip, one of which has clearly died. Now that maintenance seems to have ceased, weeds have become the dominant flora in this hellstrip. What follows are a few photos and a list of the weeds I’ve identified so far. Like all posts in the Weeds of Boise series, this list may be updated as I continue to check back in on this location.
shepherd’s purse (Capsella bursa-pastoris) and prickly lettuce (Lactuca serriola)dandelion (Taraxacum officinale)salsify (Tragopogon dubius)seed head of salsifyknotweed (Poylgonum sp.)prickly lettuce (Lactuca serriola)mallow (Malva neglecta)orchard grass (Dactylis glomerata)
Bromus tectorum (cheatgrass)
Capsella bursa-pastoris (shepherd’s purse)
Dactylis glomerata (orchard grass)
Epilobiumbrachycarpum (tall willowherb)
Lactuca serriola (prickly lettuce)
Malva neglecta (dwarf mallow)
Polygonum sp. (knotweed)
Salsola sp. (Russian thistle)
Taraxacum officinale (dandelion)
Tragopogon dubius (salsify)
Trifolium repens (white clover)
Vulpia myuros (rattail fescue)
Are there unkept hellstrips in your neighborhood? If so, what weeds have you seen taking up residence there?
“Lewis’s prairie flax is a pretty garden ornamental suited to hot, dry sites. Each morning delicate sky blue flowers open on slender arching stems, only to fall off in the afternoon and be replaced by others the next morning. In spite of its fragile appearance, it is quite sturdy and may put out a second flush of blossoms on new growth in late summer.” — Common to the This Country: Botanical Discoveries of Lewis and Clark by Susan H. Munger
When selecting plants for a waterwise garden, it is imperative that at least a portion of the plants are easy to grow and maintain and are adapted to a wide variety of conditions. This will ensure a more successful garden, both functionally and aesthetically. Luckily, there are a number of drought-tolerant plants that pretty much anyone can grow without too much trouble. Blue flax, in my opinion, is one such plant.
You may be familiar with flax as a culinary plant, known for its edible seeds which are used to make flour (i.e. meal) and oil. Or perhaps you’ve used linseed oil, a product of flax seeds, to protect wooden, outdoor furniture or in other wood finishing projects. You may also think of linen when you think of flax; and you should, because linen is a textile made from the fibrous stems of the flax plant. All of these products generally come from a domesticated, annual flax known as Linum usitatissimum – a species that has been of benefit to humans for millenia. Various species of flax have also been planted for erosion control, fire breaks, forage for livestock, and in pollinator-friendly gardens. Flax seeds, a common ingredient in bird seed mixes, provide food for birds and other small animals. All this to say, humans and flax share a long history together, and it deserves a place in your garden.
The flax species profiled here is actually two species: Linum lewisii and Linum perenne. That’s because these two species look nearly identical and are both used as garden ornamentals and in wildflower seed mixes. They are also both known as blue flax, among myriad other common names. Due to their similiarity, L. lewisii is considered by some to be a subspecies of L. perenne.
Linum lewisii is found across western North America and received its name after being collected by a member of the Lewis and Clark Expedition. The plant collection was brought back from the expedition and determined to be new to western science. It was described and named by Frederick Pursh. Linum perenne is a European species which was introduced to North America as an ornamental and has since become widely naturalized. In 1980, a naturalized selection of L. perenne was released for use in restoration plantings under the cultivar name ‘Appar’ with the understanding that it was L. lewisii. A genetic study later revealed that the cultivar was instead L. perenne. The study also provided evidence that “North American Lewis flax and European perennial blue flax are reproductively isolated,” suggesting that they are indeed two separate species.
Despite being separate species, telling them apart can be a challenge. Blue flax plants grow from a taproot and woody base and are multistemmed, reaching two to three feet tall. The stems are thin yet stringy, wiry, and not easily torn, which helps explain whyflax is such a good plant for making textiles. Short, slender leaves are alternately arranged along the length of the stems, while flower buds form at the ends of stems in loose clusters. Flowers bloom early in the day and are spent by the afternoon. They are 5-petaled, saucer-shaped, and a shade of blue – from whitish blue to deep blue – depending on the plant. Small, round, 10-chambered seed capsules form in the place of flowers, each chamber housing one or two flat, shiny, dark brown seeds. Flowers bloom daily in succession up towards the ends of stems even as the fruits of spent flowers lower on the stalk mature.
seed capsules of blue flax
A close look at their flower parts is really the only way you might be able to tell these two species apart. Blue flax flowers have five stamens topped with white anthers and five styles topped with little, yellow stigmas. The flowers of L. lewisii are homostlyous, which means their styles are all the same length and are generally taller than or about the same height as the stamens. The flowers of L. perenne are heterostylous, which means their flowers can either have styles that are much longer than their stamens or stamens that are much longer than their styles. Each plant in a population of L. perenne has either all long-styled flowers or all short-styled flowers. In a mixed population of L.perenne and L. lewisii, separating the long-styled L. perenne plants from the L. lewisii plants presents a challenge (at least for me).
long-styled blue flax flowershort-styled blue flax flower
Due to the similarity of these two species, it’s easy to see how the plants or seeds of blue flax could easily be mislabeled and sold as one species even though they are the other species. This could be a problem in a restoration planting where seed source and identity is critical, but in your garden, it’s really no big deal. Both species are great for waterwise and pollinator gardens. They are equally beautiful and easy to grow and care for. If nothing else, perhaps the challenge in identifying them will encourage you to take a closer look at your flowers and familiarize yourself with their tinier parts – an act all of us amateur botanists could stand to do more often.
Walking along railroad tracks is a pretty cool feeling. It’s also a good place to look for weeds. Active railroad tracks are managed for optimum visibility and fire prevention, which means that trees and shrubs near the tracks are removed creating plenty of open space on either side. Open areas in full sun are ideal places for a wide variety of weed species to grow. Trains passing through can also be sources or dispersal agents of seeds, so there’s a chance that you may see things growing alongside railroad tracks that you don’t often see elsewhere. All this means that railroad tracks in urban areas are great locations to familiarize yourself with your city’s wild urban flora.
I visited a small section of railroad tracks between Kootenai Street and Overland Road in Boise. At one point, this was a pretty active railroad. Passenger trains once moved along these tracks, and the Boise Depot, which is less than a mile from this location, was one of several stops between Portland, OR and Salt Lake City, UT. Unfortunately, those services ended in 1997 and have yet to resume, despite continued support for bringing passenger rail back to the region. Still, freight trains pass by with some frequency.
Managing weeds along railroad tracks in urban areas can be tricky. There is little else in the way of vegetation to compete with the weeds. The tracks are also adjacent to parks, homes, schools, gardens, and other locations that make herbicide applications complicated. The species of weeds can also vary widely from one mile to the next, so management decisions must also vary. It’s especially important that the ballast directly beneath and on either side of the tracks is kept weed free in order to prevent fires and improve visibility. All of this and more makes weed control along railroad tracks one of the most challenging jobs around. Luckily, for someone that likes to look at weeds, it means there will always be interesting things to see near the tracks, including for example this colony of harvester ants that I came across while identifying weeds. I was happy to see that they were collecting the samaras of Siberian elm (Ulmuspumila), one of several weedy trees in the Treasure Valley.
What follows are a few images of some of the weeds I encountered along the railroad tracks between Kootenai Street and Overland Road, as well as a list of the weeds I was able to identify. The list will grow as I identify the mystery weeds and encounter others that I missed, as is the case with all posts in the Weeds of Boise series.
Anyone who has maintained a garden or small farm knows that with all the work it takes to keep up on the garden itself, outlying areas can quickly become overtaken by weeds. Low on the list of priorities, areas outside of our garden borders are ideal locations for wild urban vegetation to thrive. Pulling all the weeds within the garden is a big enough task as it is; thus, weeds out of our reach are left to their own devices, occasionally getting mown down by a string trimmer or brush mower (if time allows), but otherwise living largely unscathed. And so, places such as these are excellent for familiarizing oneself with our wild urban flora.
I found an example of this scenario at the Ahavath Beth Israel Synagogue Garden in Boise, Idaho. This community garden is a partnership between Congregation Ahavath Beth Israel (CABI) and Global Gardens, providing refugees in the area an opportunity to grow food for their families and participate in community activities.
When I visited this site, it was clear that the weeds on the edge of the garden had been mowed down at some point. New plants had popped up after the fact while others were in the process of recovering from the “haircut” and putting on new, shrubbier growth. The mowing and the fact that it was late in the summer made identifying remnants of earlier weeds too difficult to bother. Most of the weeds that I did find were either summer annuals or perennials. A visit in the spring would reveal an entirely different cast of characters.
I stayed on the border of the garden, not wanting to invade anyone’s plot or snoop around too much. The point of the visit was to highlight weeds found outside of the borders of a garden anyway. I would imagine that, since the garden is used to grow annual fruits and vegetables, most of the weeds in the beds would be annuals as well. Longer-lived weeds don’t generally tolerate regular disturbance and instead find refuge in unkept areas outside of cultivation.
Below are a few photos from the site along with a preliminary list of the weeds that I found.
salsify (Tragopogon dubius)
puncture vine (Tribulus terrestris)
field bindweed (Convolvulus arvensis)
Siberian elm (Ulmus pumila)
common mallow (Malva neglecta)
black medic (Medicago lupulina)
Weeds found at the Ahavath Beth Israel Synagogue Garden:
Amaranthus spp. (pigweed)
Bassia scoparia (kochia)
Chenopodium album (lamb’s quarters)
Chondrilla juncea (rush skeletonweed)
Convolvulus arvensis (field bindweed)
Conyza canadensis (horseweed)
Digitaria sanguinalis (crabgrass)
Epilobium brachycarpum (tall annual willowherb)
Euphorbia maculata (spotted spurge)
Hordeum jubatum (foxtail barley)
Lactuca serriola (prickly lettuce)
Malva neglecta (common mallow)
Medicago lupulina (black medic)
Oenothera biennis (common evening-primrose)
Plantago lanceolata (narrowleaf plantain)
Polygonum aviculare (prostrate knotweed)
Rumex crispus (curly dock)
Setaria sp. (foxtail)
Sonchus sp. (sow thistle)
Taraxacum officinale (dandelion)
Tragopogon dubius (salsify)
Trifolium pratense (red clover)
Ulmus pumila (Siberian elm)
Verbena bracteata (prostrate vervain)
Like all posts in the Weeds of Boise series, this will be updated as I identify and photograph more of the weeds found in this location.
In spite of a global pandemic, the third annual Boise Goathead Fest took place last Saturday in Boise, Idaho. In order to make it happen, organizers had to think creatively, completely reenvisioning the event in order to keep the community safe and healthy. This, of course, meant no giant bike parade and no large gathering in the park. Instead, members of individual households embarked on their own socially-distanced bike rides, meeting up in small groups for a wide variety of mini-events across town. An online radio show made possible by Radio Boise provided the day’s soundtrack and kept us all up to date with regular live announcements.
On Saturday morning, Sierra and I decorated our bikes and ourselves and headed out on our two-person bike parade. Our first stop was the Goathead Monster’s Lair located in the alley behind Boise Bicycle Project. There we picked up food, beverages, and a map. The list of places to go and things to see was extensive. At our relaxed pace, there was no way we were going to see it all, which wasn’t really our goal anyway. Times are strange, and we were just happy to be out in the world taking part in another Goathead Fest.
Entrance to the Goathead Monster’s Lair
2020 COVID Edition Boise Goathead Fest Map
Learning some facts about goatheads with Mr. A on guitar and violin
Sierra and I next to one of many goathead-themed art installations featured around town
Bikes were allowed at Idaho Botanical Garden for one hour only – a Goathead Fest exclusive!
Not only is the Goathead Fest a celebration of bicycles and community and an opportunity to raise money for pedal-powered non-profits in the Treasure Valley, it’s also a way to bring awareness to a noxious weed responsible for countless flat tires year in and year out. Tribulus terrestris is the bane of bicyclists. Its round, spiky fruits lie in wait to royally ruin our rides. Thanks to collection efforts that take place in the months leading up to the Goathead Fest, thousands of pounds of puncture vine are removed from our streets each year.
This year, another round, spiky ball threatened to ruin our ride. This threat is much smaller and considerably more damaging. Invisible to the naked eye, it has infected hundreds of members of our community, killing many of them, much like it has done in communities across the world. With the threat of COVID-19 looming over our heads, the Boise Goathead Fest felt and looked much different. We masked up and tried to keep our distance from each other. We dispersed ourselves across the city and enjoyed the company of much smaller crowds. As someone who, apart from work and occassional trips to the store, has largely removed himself from social gatherings, I felt nervous to be out. Thanks to the thoughtfulness and awareness of Goathead Fest organizers, my fears were largely soothed. It was important for me to, once again, be together with Boise’s bicylce community and feel a renewed sense of hope for the future.
We are all looking forward to the day when the only round, spiky ball that threatens to keep us off our bikes are those blasted goatheads, and even those – if we keep at it – might someday be a thing of the past.
More Party Time for Puncture Vine on Awkward Botany
I first learned about Moon Trees in the fall of 2015. One of the trees – a loblolly pine – had been planted at an elementary school just down the street from where I was living at the time. It wasn’t a new thing – it was planted back in 1977, during the period when most other Moon Trees where being planted around the country and the world – but because it wasn’t doing too well, it was in the news. Members of the community, concerned about its long-term survival, were pitching in to help keep it alive. Once I was made aware of it, I also became concerned and decided to go check on it. I even wrote a post about it, which you can read here.
Now that nearly 5 years have passed, I figured I should go check on it again. I hadn’t heard any more news about it, so I assumed it was still hanging in there, but who knows? Maybe not. Since I was going to be on that side of town for Father’s Day, I made plans to stop by. My dad hadn’t seen the tree yet, so he decided to join me.
As we approached Lowell Elementary on our bikes, I was half-expecting the tree to be gone. It was in pretty sad shape when the community stepped in to help it. Braced for this possibility, I anxiously peered down the street as we biked closer. When the tree came into view, I felt relief and announced, “There it is!”
All this time later, it still looks a little rough. The majority of its bark remains largely obscured by crusty, dried up sap, and its canopy isn’t as full as it likely would be if it was a picture of health. But it’s alive and, surprisingly enough, still growing taller, reaching for the moon.
Any loblolly pine would feel out of place in Idaho – it’s a species whose distribution spans the southwest region of the United States, which is starkly different from the northwest – however, this individual in particular is an anomaly. The seed it sprouted from took a journey into space, circled the moon a number of times and then, as a sapling, was planted in Idaho (of all places). Now, over 40 years later, it stands as a symbol of resilience. Something we could all use right now, I’m sure.
The Boise River, which winds its way through the City of Boise, is flanked by a series of parks known collectively as the Ribbon of Jewels, named in honor of prominent women in the community. Most of these parks are vast expanses of turfgrass scattered with large trees and are meticulously maintained, except near the river where the vegetation is allowed to run a little wild. It is within these narrow strips of land, bordered on one side by the river and the other by regularly mowed turfgrass, that a veritable nature walk can be had right in the heart of the city.
While a few native plant species can be found in these strips, much of the vegetation is introduced. Some of the non-native trees and shrubs may have been intentionally planted, while others came in on their own. Most of the grasses and forbs in the understory are weedy plants commonly seen on all manner of disturbed lands. There are also, of course, a few weeds specific to riparian areas. Due to the wild nature of these strips and the abundance of introduced plants, the river’s edge makes for a great place to become acquainted with our wild urban flora.
Looking at the northwest corner of Ann Morrison Park from the Americana Boulevard Bridge
Because these parks (which include the Boise River Greenbelt) stretch for miles through the city, practically any spot along the way could be a good place to look for weeds. I chose to narrow my search to the northwest corner of Ann Morrison Park. What follows are a few images of some of the plants I found there, along with a list of what I was able to identify during my brief visits this spring. The list will surely grow as I check back from time to time. If you’re interested in learning more about the Boise River and its importance – not just to the humans who call Boise home, but also to myriad other living organisms – check out Boise River Enhancement Network and the work that they are doing to help protect and preserve this invaluable ecosystem.
yellow flag iris (Iris pseudacorus)
Russian olive (Elaeagnus angustifolia)
common mullein (Verbascum thapsus)
climbing nightshade (Solanum dulcamara)
cleavers (Galium aparine)
a strip of cheatgrass (Bromus tectorum)
seed head of dandelion (Taraxacum officinale)
western salsify (Tragopogon dubius)
bull thistle (Cirsium vulgare)
Amur honeysuckle (Lonicera maackii)
creeping buttercup (Ranunculus repens)
Weeds found at the northwest corner of Ann Morrison Park (while several of the trees and shrubs at this location are introduced, I only included those species that are generally considered to be weedy or invasive):
Amorpha fruticosa (false indigo bush)
Anthriscus caucalis (bur chervil)
Arctium minus (common burdock)
Bromus tectorum (cheatgrass)
Capsella bursa-pastoris (shepherd’s purse)
Cerastium vulgatum (mouse-ear chickweed)
Cirsium arvense (creeping thistle)
Cirsium vulgare (bull thistle)
Chondrilla juncea (rush skeletonweed)
Convolvulus arvensis (field bindweed)
Conyza canadensis (horseweed)
Cynoglossum officinale (houndstongue)
Descurainia sophia (flixweed)
Elaeagnus angustifolia (Russian olive)
Erodium cicutarium (redstem filaree)
Euonymus fortunei (winter creeper)
Galium aparine (cleavers)
Hordeum murinum ssp. glaucum (smooth barley)
Iris pseudacorus (yellow flag iris)
Lactuca serriola (prickly lettuce)
Lamium amplexicaule (henbit)
Lonicera maackii (Amur honeysuckle)
Malva neglecta (common mallow)
Medicago lupulina (black medic)
Parthenocissus quinquefolia (Virginia creeper)
Plantago lanceolata (narrowleaf plantain)
Poa bulbosa (bulbous bluegrass)
Polygonum aviculare (prostrate knotweed)
Ranunculus repens (creeping buttercup)
Rumex crispus (curly dock)
Sisymbrium altissimum (tumble mustard)
Solanum dulcamara (climbing nightshade)
Sonchus sp. (annual sow thistle)
Taraxacum officinale (dandelion)
Tragopogon dubius (salsify)
Trifolium repens (white clover)
Ulmus pumila (Siberian elm)
Verbascum thapsus (common mullein)
Like all posts in the Weeds of Boise series, this will be updated as I identify and photograph more of the weeds found in this location.
There is an old Pizza Hut on the corner of Ann Morrison Park Drive and Lusk Street. I’m not sure how long it’s been closed (if someone knows for sure, please let me know), but it has to be well over a year – probably several years. It’s clear that the landscaping has not been maintained for a while. The turf grass in the hellstrips is now mostly weeds, the Callery pearsand crabapples are in need of some serious pruning, and the mugo pines and horizontal junipers are slowly dying off. On the other hand, the Oregon grapes and barberries look just fine. They never really needed our help anyway.
I like checking out lots with recently abandoned buildings because you can see in real time just how quickly weeds take over once humans stop their meddling. As the months and years pass, and as the plants that humans intentionally placed there decline, it becomes increasingly obvious that weeds truly are the wild flora of our cities.
My first few visits to this site were on March 21st, 25th and 28th of 2020. During those visits, I made a list of all the weeds that I could easily identify and noted a few individuals that I will need to come back to. What follows are photos of a few of the weeds I came across, along with a list of the weeds I was able to identify.
Every lot needs a dandelion (Taraxacum officinale).
Common mallow (Malva neglecta) in mulch.
The turf grass in the hellstrips has been replaced by several different weeds including tiny, early spring favorites like bur buttercup (Ceratocephala testiculata) pictured here and spring draba (Draba verna).
Common groundsel (Senecio vulgaris) is prolific in a bed on the north side of the building. On the east side, this plant had already flowered and gone to seed by mid-March.
The tough taproot of alfalfa (Medicago sativa) easily works its way into cracks in pavement and concrete.
A bull thistle rosette (Cirsium vulgaris) perhaps?
Cheatgrass (Bromus tectorum) was common on the site, including (perhaps not surprisingly) in this parking block.
horseweed seedling (Conyza canadensis)
Weeds found at the abandoned Pizza Hut on Ann Morrison Park Drive:
Bromus tectorum (cheatgrass)
Ceratocephala testiculata (bur buttercup)
Cirsium vulgare (bull thistle)
Conyza canadensis (horseweed)
Draba verna (spring draba)
Hordeum murinum ssp. glaucum (smooth barley)
Lactuca serriola (prickly lettuce)
Malva neglecta (common mallow)
Medicago sativa (alfalfa)
Poa bulbosa (bulbous bluegrass)
Rumex crispus (curly dock)
Senecio vulgaris (common groundsel)
Taraxacum officinale (dandelion)
Ulmus pumila (Siberian elm)
This post will be updated as I identify more of the weeds and capture more photos. I also anticipate that this lot will not be abandoned for that much longer. It’s located near Boise State University in an area that has seen a lot of development in the past few years. I can’t imagine prime real estate like this will stay feral indefinitely. Until something is done with it, I’ll keep checking in.
awkward botany 