The Sidewalk Botanist Scavenger Hunt 2020

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Urban botanizing in the age of COVID-19

Since most of my botanizing these days is while walking the woofer in a heavily urbanized part of Chicago, I thought I would see how many of these common urban plants I could observe in 2020. Want to join along?

Many of the species on the project list can actually be commonly found in urban areas around the world (urban species homogenization is a whole academic subfield!), but the ones on this list are particularly common in the Chicago region.

Here's a guide that shows a photo, snippet from Wikipedia, and map of observations:

happy botanizing, fellow sidewalk naturalists!

Posted by bouteloua bouteloua, April 16, 2020 22:18


Any other species I should add to the list?

Posted by bouteloua about 2 years ago (Flag)

maybe Procumbent Pearlwort?

Posted by astrobirder about 2 years ago (Flag)

Lamium species, Drapa verna, Cardamine hirsuta, Chaenorhinum minus (Dwarf Snapdragon), Leonuris cardiaca, Glechoma hederacea, Solidago altissmima/canadensis (not sure how you want to do that?) Commelina communis, Poa annua, Poa pratensis, Mollugo verticillata, Chicory, Wild Parsnips, Persicaria longiseta, Galinsoga quadriradiata, Securigera varia, Cirsium arvense, Melilotus sp? and Goose Grass (Elusine indica) come to mind, you don't have to include all of these by any means.

Wintercreeper, Poison Ivy, Oriental Bittersweet, various Lonicera and Greenbriars come to mind, but I'm not sure if those are too large/woody for a "Sidewalk Flora" project.

Posted by wildlandblogger about 2 years ago (Flag)

I see all of these growing in sidewalk/unmowed lawn areas:

Not sure if there's a fast way to check what's not on your list

Posted by mws about 2 years ago (Flag)

Herniaria species (or H. glabra and H. hirsuta), have you got Polygonum aviculare yet?, Plantago lanceolata, Oxalis corniculata...

Posted by alexis_orion about 2 years ago (Flag)

awesome, added a bunch to the project list

Posted by bouteloua about 2 years ago (Flag)

I thought of a few more:
Potentilla argentea (I hope I spelled that right),
Hordeum murinum,
Ailanthus altissima,
Ballota nigra,
Arenaria serpyllifolia,
Cymbalaria muralis.

Posted by alexis_orion about 2 years ago (Flag)

some of those were already on, but I added those and a few more, like Potentilla indica and Setaria pumila which I see growing in my alley :)

Posted by bouteloua about 2 years ago (Flag)

thanks! one more: Polycarpon tetraphyllum

Posted by alexis_orion about 2 years ago (Flag)

Added! Interesting spotty distribution in the US.

Also Portulaca oleracea!

Posted by bouteloua about 2 years ago (Flag)

of course!

Posted by alexis_orion about 2 years ago (Flag)

Alchemilla sp., Argentina anserina, Tussilago farfara, other Arctium species other than minus, especially lappa and tomentosum, Lepidium sp., Erysimum cheiranthoides, Achillea millefolium, Artemisia vulgaris, Scorzoneroides autumnalis, Sonchus sp. and Bunias orientalis probably. I better stop here.)
Also small Polygonum are almost unidentifiable by pictures alone, I upload all mine as Polygonum sp.

Posted by marina_gorbunova about 2 years ago (Flag)

I keep remembering more: Mycelis muralis, Parietaria judaica

Posted by alexis_orion about 2 years ago (Flag)

just saw that Senecio vulgaris is not on the list, could you add that too? sorry!

Posted by alexis_orion about 2 years ago (Flag)

no prob that's what this is for!

how the heck could I forget Senecio vulgaris? :)

Posted by bouteloua about 2 years ago (Flag)

@nathantaylor might have a few additions for more southern climes

Posted by bouteloua about 2 years ago (Flag)

I'd add E. prostrata, E. nutans, E. hyssopifolia, E. thymifolia, E. ophthalmica, E. hypericifolia, and E. hirta without a second thought. E. stictospora is a bit more Texas/New Mexico/Arizona specific but is really common in sidewalk cracks out here. Several others like E. vermiculata occasionally show up in abundance in sidewalks on college campuses between the Rio Grande and Pecos River, but that may be a bit too geographically specific. E. thymifolia only really occurs in Florida (where it is a sidewalk weed) in the US, but is a pantropical sidewalk weed and occurs many places around the world but you may want to exclude it. In much of the southern half of Florida E. blodgettii is like E. maculata is elsewhere. Outside of Anisophyllum, E. peplus, E. graminea, and E. davidii (possibly E. dentata?). I'm sure I'm missing others. If including CA, E. terracina, E. segetalis, E. oblongata, and probably some other members of subg. Esula should be added.
For Medicago, M. polymorpha, M. minima, M. orbiculata, M. arabica (I think that's all).

Alternanthera caracasana, A. pungens.

Blitum nuttallianum (probably)
Erodium cicutarium
Calyptocarpus vialis
Galium aparine
Modiola caroliniana
Solanum elaeagnifolium
Maybe Oenothera suffulta, O. curtiflora, and O. lanciniata?
I'm sure I'm missing a ton, but I think this gets the big ones for much of Texas that aren't already on your list. You might ask sambiology (DFW area) or alisonnorthup (Austin) for more Texas plants.

As an aside, it's a bit difficult for me to know what to add since I live and spend the vast majority of my time in the country (e.g., Oenothera engelmannii and Mentzelia strictissima, though considered rare in Texas, are common "weeds" where I live and the largest cities that I visit on any kind of regular basis are Lubbock and Midland, TX). Also, I'm sure you know this but this is a pretty ambitious project. Every sidewalk is different with a mix of regional native weedy species and common cosmopolitan plants. The native weed component often varies from place to place as strongly as the external flora itself does. As such, the sidewalk weeds are not quite the same across DFW, San Antonio, or Houston, TX (the more homogenized places in Texas as far as urban flora goes). It's even more different if you include more rural city sidewalks like the ones in Alpine, Lamesa, or Snyder, TX. You might as well forget about sidewalks in the country. Still, I look forward to seeing how all this turns out as sidewalk botany is a lot of fun. That is, if you have a sidewalk. :-)

Posted by nathantaylor about 2 years ago (Flag)

Dang, I just realized how long that is. Sorry about that!

Posted by nathantaylor about 2 years ago (Flag)

I believe there's a problem in not having an ability to choose which photos to add, as many of those species listed are found not only in urban areas, but in the wild too, and already there're some photos from the forest with such species and in the summer with meadows blooming it would be worse.

Posted by marina_gorbunova about 2 years ago (Flag)

yeah it's not intended to be a perfect complete list, just a different way to highlight our common weedy little plants : )

Posted by bouteloua about 2 years ago (Flag)

And I like it, thank you for creating it.)

Posted by marina_gorbunova about 2 years ago (Flag)

It's a fun little project. I'm curious how the list will look as time goes on and species get added. I don't think I'll be able to participate that much as the virus actually means walking sidewalks less often more me. :-)

Posted by nathantaylor about 2 years ago (Flag)

I don't know if you are only interested in little weeds, but for growing in the gutter I found this rather interesting (- not being a plant person)

Posted by susanne-kasimir almost 2 years ago (Flag)

how strictly do you define sidewalk? I found a pansy growing in a crack in the concrete steps/walkway up against a house (a doormat is covering the concrete)

Posted by booksandcookies almost 2 years ago (Flag)

cute! I love finding "normal" garden plants growing in funny spots.

this is a collection project, so it's not actually possible to add observations manually to it. It's just a listing a bunch of plants that are very commonly found growing along sidewalks :)

Posted by bouteloua almost 2 years ago (Flag)

Oops sorry I sent you a DM message, didn't see this as a way to add species. These are all common lawn weeds in South Mississippi but I literally observed them in sidewalk cracks. If you think that will bring in too many non-sidewalk observations if they are listed, I understand, but anyway:
Ambrosia artemisiifolia
Richardia brasiliensis
Croton glandulosus
Eremochloa ophiuroides
Sida rhombifolia
Panicum repens
Diodia virginiana
Phyllanthus urinaria
Euphorbia hyssopifolia
Sporobolus indicus
Digitaria ciliaris

Posted by janetwright almost 2 years ago (Flag)

Paraguayan Purslane Portulaca amilis

Posted by janetwright almost 2 years ago (Flag)

Phyla nodiflora

Posted by lappelbaum almost 2 years ago (Flag)

I wish I would have seen this project sooner. I was wondering, how loose are we defining side walks and how common is "common"?

In any case, I might suggest
Eragrostis pectinacea
Eragrostis pilosa
perhaps other Eragrostis sp.
Erigeron annuus
Phytolacca americana
Chaenorhinum minus
Mirabilis nyctaginea
Lotus corniculatus
Securigera varia
Bidens vulgata
Echinochloa crus-gali
Persicaria maculosa
Persicaria lapathifolia
Panicum dichotomoflorum
Panicum capillare
Leucospora multifida
Potentilla norvegica
Melilotus sp.
Solanum dulcamara
Solanum emulans
Acalypha rhomboidea
Hordeum jubatum
Atriplex prostrata

I'm gonna stop there for now.

Posted by dziomber almost 2 years ago (Flag)

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