Street Plants of the Urban - Riparian Ecotone

Light industrial - riparian ecotone, Laramie, Wyoming.

ecotone (noun): Transitional area between two different ecosystems, such as a forest and a grassland. … contains elements of both bordering communities as well as organisms which are characteristic and restricted to the ecotone. (The Encyclopedia of Earth)

Around here we assume that street plants—the green waifs of urban habitats—are exotic species. But not always. Some natives are quite capable of invading and thriving in human ecosystems. They do especially well where there’s a source of extra water—ditches, rain gutters, drain pipes, runoff from pavement. People generally consider these plants to be pesky weeds, even though they’re native.

The warehouses west of my house are fertile ground for weedy natives. Development has exposed lots of bare dirt—open habitat. There’s less concern about keeping things tidy than in town; weeds don't offend and left alone. Water runs off the roofs and pavement. And just west of the warehouses is the Laramie River, lined with riparian vegetation. Several riparian plants are willing and able to take up residence among the warehouses.

Russet seed heads of wild licorice, Glycyrrhiza lepidota.

Wild licorice has taken advantage of bare soil along the entrance to the lumber yard. It’s native, but is considered a weed “of meadows, pastures, prairies, ditch and river banks and waste areas.” (from Weeds of the West, 1991). The fruit are covered in tiny hooks—ideal for dispersal.

Epizoochory: transport on the exterior of an animal, e.g. wild licorice burs in dog fur.

On the west side of a warehouse, a box elder (also called boxelder maple) established itself next to a pile of old pallets in a corner where no one will bother it. I blogged about this tree last summer. It’s leafless now, looking rather dead.

Box elder, Acer negundo.

But the buds hold a promise: it will again be warm enough to grow!

Small cottonwood trees grow along a ditch carrying rainwater from neighborhood storm sewers to the river. Whether they started as seeds or suckers is impossible to say. One fell earlier this year, taking the chain link fence with it. I presumed it was precariously rooted in the ditch bank, and high winds took it down. But when I looked over the bank, I discovered this:

It was a beaver that felled the cottonwood, not wind. Now it can feast on bark and twigs (soft inner parts), and collect branches to add to its lodge—maybe the big one nearby on the river.

Tell-tale tooth marks.

Nearby beaver lodge on a warm green day. Have faith, it will be like this again!

Street plants are the subject of a bi-monthly virtual gathering started by Lucy and now hosted here. Do you have news of street plants? If so, please leave a link in a Comment below.

Calling all Street Plant Lovers

Knotweed, pigweed, birdweed, waygrass,

wireweed, doorweed, pinkweed, matgrass.

Polygonum aviculare is a plant of many names.

The bimonthly virtual gathering of Street Plant lovers has moved here to Urban Plants, Urban Rocks because Lucy of Loose and Leafy is packing her blog away in mothballs. I’m proud to be the new host, but I hope it’s temporary. To see why, check out Lucy’s insightful and entertaining street plant posts. Many of us would be happy to hear that she has pulled Loose and Leafy out of the mothballs, given it a good airing, and put it back online … perhaps in spring?

P. aviculare demonstrates its wireweed moniker.

This is one of the most widespread weeds pioneer plants in the world (source).

“It can be quite an adventure, looking for Urban Wild Plants. You can keep an eye out for them as you walk around town or choose a street at random and see what you can find - grass next to rubbish bins, daisies in the kerb, buddleia on the tops of buildings.”—Lucy on Street Plant Blogging

Knotweed in full bloom, with white flowers less than 2 mm across.

So keep your eyes and mind open, and camera handy, and consider sharing (via linky box below) your encounters with a ...

Street Plant is not a blossom grown in a garden.

It’s a weed that’s been cast out.

A seed that grows even after its been stomped in the dirt.

A sprout pushing up from beneath the sidewalk,

pushing through the cracks and breaking them open.

No tending hands to feed it —

It’s a seed grown from pure light and nourished by the deepest roots.

It’s small, it’s got sharp thorns, it’s hard to kill.

But when it bears fruit those fruit will not be plucked for someone else’s harvest.

That fruit will drop to the ground as seeds.

Seeds to spread in darkened parking lots

as boomboxes play full volume and wheels bark at full speed.

—from The Never Ending Now courtesy Street Plant skateboards
Used with permission.

Street plants dance with their shadows.

to the Linky Box.

Paste your name and a link to your street plants post in the box below. If I’ve done everything correctly (fingers crossed!!), you will show up on the the list. Mister Linky asks that you add a comment—not necessary but it would be great to hear from you.

The box will disappear October 26. [Mister Linky is now on Mountain Daylight Time.]

cheers :-)

Cottonwoods, Utilities Lines & Dogs

Our valley gets only 12 inches of precipitation per year (semi-arid).  It's covered in grass, with stands of shrubs here and there.  Greens are subdued—the gray-greens and blue-greens of drought-tolerant plants.  But where there's water, everything’s different.  Cottonwoods, willows, tall grasses and sedges line streams, and the greens are rich and deep.

Here’s a Google Earth view of the Laramie Valley.  Our town on the southeast edge.  Dark green riparian zones and occasional irrigated fields line creeks and rivers.

 The green arrows above and below show where my foot was stuck on Saturday.

Laramie West Side and river.

Why was it stuck?  Because every two months, Lucy Corrander of Loose and Leafy kindly hosts a stuck-foot meme:

“… plant your foot firmly in a roughly random place and see what you can see without moving. Best is when you plant both feet. If you are on a slope or some other kind of difficult ground you may need to move the other foot for the sake of balance - but you mustn't move the 'stuck' foot. You can bend your body this way and that. You can lean forward and twist at the waist - but you mustn't swivel that stuck-foot.”

A stuck foot.

My place was not random (never is, but no one objects).  I chose a small stand of cottonwoods on the edge of a patch of prairie just east of the ranch supply warehouse.  I've been wondering why water-loving trees grow between a road and a dry grassland.  When I investigated, the reasons were obvious:  water and sewer lines.  Most likely it's the sewer line.  Tree roots in sewer lines are “one of the top ten plumbing problems”—

“Mother Nature has equipped many trees with sophisticated sensing capabilities. The trees send out feeder roots in all directions in a search for both nutrients and water. … If tiny feeder roots discover these cracks [in older sewer lines] they enter the pipe … Once inside the pipe the roots enlarge and gorge themselves on the plentiful supply of water and food.”  Source.

There's a sewer line here, as well as a water line.

Possibly someone planted these trees but I doubt it.  People avoid narrowleaf cottonwoods (Populus lanceolata) in landscaping because they’re notorious sucker-ers.  I bet the multiple stems (trunks) are all one tree underground.

It was a good time to be stuck:  clear sky, no wind, warm early-morning light.

The trees aren't large, but they already show the narrowleaf's two kinds of bark:  young smooth and white up high; older cracked and furrowed below.

One tree has two tiny branchlets growing out of older bark.  How does this happen?

It was a good place to be stuck, with lots to see.  The trees' shade now makes the site more favorable.  All the past disturbance—entry road, parking lot, utility lines—created habitat for invasive non-natives, but I don't mind.  It's good there are plants that can grow in these places.

Yellow sweet clover (Melilotus officinalis), from Eurasia.  It did well this year.
Some years it’s barely noticeable; in others it seems to take over.

Rosettes of Canada thistle (Cirsium arvense)—non-native and designated noxious.

Native salt grass (Distichlis spicata) is taking back the street.

Foxtail barley (Hordeum jubatum) and curlycup gumweed (Grindelia squarrosa, yellow flowers).
 They're native but deemed weedy. In my yard I keep the beautiful foxtails but pull up gumweeds.

Twisting around as far as I could, I saw gumweed, salt grass and wild purple asters.

Sewer clean out, with a milkweed (bottom center), yellow sweet clover and wild aster.

My field assistant ended up in a photo ... by accident.  Sparky was always happy to pose, but Emmie has other priorities, at least for now (only two years old).

Oops.

In memory of Sparky, great field dog and pal.

Emmie’s just as great, in her own way.

But all dogs are!  Patches and Apache, Wind River Mountains, 1996.

Ellie at Devils Tower, mid 1980s.

For more stuck-foot posts, see Comments at this month’s virtual gathering. [Linky box will be active when Lucy's charger arrives ... online disasters come at the most inopportune moments!]

If you're interested in stuck-foot adventures, sign up here.  It’s easy, fun and always interesting.

Last Hollyhocks in Morning Sun

The hollyhocks in my yard are winding down; just a few flowers left.

Mine are all volunteers.  They’ve done well this wet summer.

Veritable multitudes of schizocarps!

Hollyhock fruits are dry discs that split into many thin segments, each with a seed.  Hence the term schizocarp—split or divided fruit.  On my plants, the segments (mericarps) stay trapped in the old dried sepals until a hard wind blows or someone brushes against them and spills them on the walk.

Mericarps are about 5 mm across.

Three papery mericarps, each holding a seed.

Portraits of a Box Elder

box elder (Acer negundo): A tree. “box” because its wood was used to make boxes; “elder” because the leaves suggest those of elderberry.

Another name for box elder is ash leaf maple, appropriately.  It's a maple (genus Acer) but the leaves look more like ash leaves—compound with leaflets.  Most maple leaves are simple.

Box elder is fast-growing, soft-wooded, short-lived.  “It typically occurs in moist to wet soils along streams, river flood plains and in low woods” (source).  In general, it thrives in open sites on bare soil.  So it’s a capable urban pioneer—a street plant.

One of my neighbors is a boxelder.  It grows just across the street, on the west side of the warehouse in a corrugated metal corner below the sky, with other tough urban types: Canada thistle, curlycup gumweed and trash.

Box elder with pink thistle, yellow gumweed and cheap throw-away stringer pallets.

Barn swallows roost close by in the evening.

Swallows all in a row, above door.

Wildfires are burning 500 miles to the west, so the sky was smoky, with an eerie red sun.

Sun sets behind abandoned cabin and discarded pallets.

This post is my contribution to the August gathering of street plant fans, kindly hosted by Lucy  of Loose and Leafy.