Monday, June 22, 2015

Take Back the Street

Asphalt is sometimes referred to as a flexible pavement. This is due to its ability to largely resist the stress imposed by slight settlements of the subgrade without cracking [italics added] – European Asphalt Pavement Association
Yeah right ... we'll show the EAPA what we can do!

A crack in the asphalt snakes all the way across Flint Street from my curb.  Pioneer plants seized the opportunity as soon as a bit of habitat appeared.  Now there’s a winding lineup of greenery.  It’s the usual bunch.

Cheatgrass (Bromus tectorum) gone to seed,
in a patch of large-bract verbena (Verbena bracteata).
Verbena flowers are only a few millimeters across.
Tumble mustard (Sisymbrium sp.) with a flower 5 mm across, and young capsules.
These mustards usually grow much taller, but being a pioneer species, they adapt.
Kochia weed (Kochia scoparia) is the most common pioneer plant in my yard.
In the right situation it grows into a tumbleweed.  This one probably won’t.
Prostrate knotweeds (Polygonum aviculare) in lower crack.
Tiny Russian thistle (Kali tragus, syn. Salsola kali) in crack above. 
Russian thistle in center of photo.  The little seedling looks innocent enough,
but in maturity it will be prickly with sharp spine-tipped leaves.
This is the iconic tumbleweed of the American West.

Nothing’s permanent, everything changes.  Asphalt gives way to pioneer plants.  Pioneers are replaced by bigger, longer-lived plants when there's enough space, dirt and debris.  Since the City appears to be ignoring this botanical invasion, the plants may well take back the street.

The crack widens on the south side of the street, with almost enough plants to be vegetation.
Dandelion and cheatgrass thrive in the asphalt ecosystem.

This post is my contribution to Lucy Corrander’s June street plants gathering.