gcwarbler's Journal

I was taking a look again at the earliest images that I've scanned and uploaded to iNaturalist. Those date from the late 1960s (see below). There are now thousands of earlier images of organisms on iNaturalist but the majority of them are images of museum specimens of plants, insects, mollusks, etc. So I began looking for the earliest images of organisms in the field, so to speak, using the simple filters on the Explore page.

I quickly had to qualify my search of old observations on iNaturalist. First, I summarily ruled out those museum specimens, and since I wouldn't expect to see photographic field evidence prior to 1900, I started my search at the beginning of the 20th Century. I also disregarded the unfortunate set of modern observations with erroneous observation dates (evident from high quality digital images dated to the 1900's, etc.).

I began to uncover a number of "observations" from secondary sources like images out of newspapers of beached whales, captured sharks, etc., and photos from published research papers. Those certainly provide "evidence" of an organism, but the dates are sometimes estimated or very approximate and the original "observer", i.e. the photographer, is rarely stated. These include such examples as a Pel's Pouched Bat from Niangara, Congo, presumably a captured specimen and dated May 27, 1913, documented in a Bulletin of the American Museum of Natural History, and uploaded in 2014 by @jakob :
https://www.inaturalist.org/observations/604690

So I began combing through observations chronologically, looking for the earliest first-hand personal evidence of living or recently dead animals or plants.

There is a photo of a public gathering around a Great White Shark, presumably captured off the coast of Turkey in 1920, and uploaded in 2021 by @gorkialkan.
https://www.inaturalist.org/observations/93239174

The earliest image of any animal which is not a captured or museum specimen seems to be the following beached Rorqual (Baleen whale) in Tampico, Mexico, dated February 4, 1922. @josecastaneda2 uploaded the image, stating that it is from the digital Historical Archives of Tampico.
https://www.inaturalist.org/observations/102773699

The earliest first-person, non-photographic account of an organism seems to be W. C. Russell's notes on Yellow-bellied Marmots ("woodchucks") in Elko Co., Nevada, recorded in his field journal for July 13, 1935, and uploaded by @floydch in 2019:
https://www.inaturalist.org/observations/26545985

And--drum roll, please--the earliest first-hand, field photo on iNaturalist of a living organism seems to be this Koala documented in Victoria, Australia on December 31, 1935. https://www.inaturalist.org/observations/77862210
I've left a message for @nimzee, who uploaded the image in 2021, for more details on the photographer, etc. It does not appear to be a commercial or secondary source image, so I'll look forward to learning more about its provenance.

The earliest observations of any plant uploaded to iNaturalist are apparently some European Larch trees in the background of a set of family ski vacation images in the French Alps, taken by L. Hunault in January 1936, and uploaded in 2021 by @mercantour.
https://www.inaturalist.org/observations/67659308

It gets a little difficult when trying to pin down the earliest first-hand, first-person photos of an organism, since it isn't often clearly stated that the iNaturalist/uploader was the person who took the image. But there are some likely candidates.
In 2020, @hoaryherper uploaded a couple of herp pics from his childhood. The earliest is one he took of a Blue Racer grabbed by his friend John Evans on June 20, 1949 in Ohio:
https://www.inaturalist.org/observations/47768061
@hoaryherper also uploaded an image of himself (taken by John Evans) with a captured Prairie Kingsnake in Pennington Co., South Dakota from June 21, 1955:
https://www.inaturalist.org/observations/41106492

@blastcat uploaded a couple pictures of recently-caught fish at Chincoteague, Virginia in June 1955. These are akin to the above documentation of a Great White Shark but these are family photos, in the first instance taken by his grandfather:
Red Drum: https://www.inaturalist.org/observations/106281440
Billfishes: https://www.inaturalist.org/observations/106281439

My late pal Greg Lasley got minimal documentation with his dad's Bell and Howell movie camera of an Eastern Cottontail in Shillington, Pennsylvania, on/about September 19, 1962, during a family trip:
https://www.inaturalist.org/observations/52178520
And just 10 days later, about Septermber 29, 1962, found himself with his family in La Rochelle, France, using the same camera to document a Gray Heron:
https://www.inaturalist.org/observations/52178521

My own earliest personal upload of a first-hand field image dates from May 1969, a butterfly photographed in Taiwan with my first new SLR camera, a trusty Minolta SRT-101:
https://www.inaturalist.org/observations/69211543

So I offer a challenge for anyone to mine the iNaturalist database of images to find earlier personal, first-hand, field observations. What can you find?

I just glanced at the project page for Austin's City Nature Challenge 2022 and was tickled when I saw the leading species for the first day of the event: Rain Lily!

Just like 95% of Texas, much of the Austin area is in moderate to exceptional drought, although the region is split about half and half in and out of the drought areas:

It was only a brief passing storm system last Monday that prompted the appearance of the rain lilies ... but we'll take 'em!

During a recent bioblitz at the Timberlake Biological Field Station, some of us were discussing how to access older scientific literature which might be available in digital form online. I'll have more to say in a follow-up post about my favorite archive, the Biodiversity Heritage Library,
https://biodiversitylibrary.org
https://about.biodiversitylibrary.org
but I thought I'd take a moment to list some other potential online archives which may be useful. Here are some I've discovered. There certainly may be others:

Google Scholar
https://scholar.google.com/schhp?hl=en
A good starting place. The results might link to free pdf downloads, pay sites, or only literature citations without digital access, but it's pretty thorough--often too thorough, bringing up distantly related or unrelated titles. You can test it by searching for your favorite plant or animal like "Calyptocarpus vialis", "Jalisco Petrophila", or even a location like "Timberlake Biological Field Station".

JSTOR (a part of ITHAKA)
https://www.jstor.org
Accessing articles through their front-end search engine may involve some cost, but JSTOR downloads are available for free through many/most academic institutions (such as University of Texas, Austin Community College, etc.) and even Austin Public Library (with a library card).
https://www.jstor.org/institutionSearch?redirectUri=%2F

The Hathi Trust Digital Library
https://www.hathitrust.org
https://www.hathitrust.org/about
https://www.hathitrust.org/community

PubMed Central
https://www.ncbi.nlm.nih.gov/pmc/
Less focused on natural history, per se, but includes many relevant journals. Their Full-Text Archive Search can bring up some surprisingly useful results:
https://www.ncbi.nlm.nih.gov/pmc/journals/

SORA (Searchable Ornithological Research Archive)
https://sora.unm.edu
A great resource for searching journals like The Auk, Condor, Wilson Bulletin, and a growing list of other bird-oriented publications.

Please feel free to add links to useful resources you are aware of.

February 2022 finally broke my string of months with at least one upload of blooming Straggler Daisy (Calyptocarpus vialis), a string that dated back to March 2020. With a couple of hard freezes at the beginning and end of this February, the species never had enough growing “season” in CenTex to put out flowers. There were five observations of Straggler Daisy uploaded in the Greater Austin Metro Area during the month, but none of them show evidence of blooming:
https://www.inaturalist.org/observations?d1=2022-02-01&d2=2022-02-28&place_id=60211&taxon_id=84405
Across the state, there were a few observations of blooming Straggler Daisy in the first few days of February, particulary in Laredo, the LRGV, and on the coast, but including one in the DFW area on February 1 as a hard freeze set in:
https://www.inaturalist.org/observations?d1=2022-02-01&d2=2022-02-28&order=asc&order_by=observed_on&place_id=18&taxon_id=84405
I should have gotten out in my neighborhood on February 1 as well and might have kept my string alive. No one documented flowers on the species again in Texas until February 22 on the coast at Corpus Christi:
https://www.inaturalist.org/observations/107270482
I failed to find flowers on any Straggler Daisy on a 4-mile walk in the neighborhood today (March 3).

When I go on a targeted iNaturalist trip, whether with a group or on my own, my focus on Nature is pretty intense. But I’ve wondered occasionally how this compares to other people’s experience and outcomes. Just this morning (March 1, 2022) I’ve completed the uploads from a rather grueling six day journey last June to the Texas Panhandle. (Other trips and obligations delayed these uploads.) So I’ve compiled some overall stats from the trip, as follows.

Over the six days and five nights of the trip, I made stops at eight target destinations:

— Timberlake Biol. Station (Mills Co.) with other iNaturalists
— Lake Meredith NRA (Moore/Floyd Co.)
— Rita Blanca Lake (Dalhart, Hartley Co.)
— Rita Blanca Nat. Grassland (Dallam Co.)
— Palo Duro Res. (Hansford Co.)
— McClellan Creek Nat. Grassland (Gray Co.)
— Caprock Canyon SP (Briscoe Co.)
— E.V. Spence Res. (Coke Co.)

There were other miscellaneous roadside stops and observations most days. Most of my focus was botanical, trying to learn new plants in the South Plains and Panhandle, but of course I tried to document any critters I encountered that would sit for a photograph. I made concerted mothing efforts at three of the locations (Timberlake, Rita Blanca NG, and E.V. Spence Res.).

I got home with a little over 2,200 photos, out of which I eventually created 707 observations of 431 taxa of plants and animals (according to iNat’s accounting). Excluding two days which were primarily long travel days, my uploads amounted to 652 observations from 4 primary field days, thus averaging 163 observations/day on those intense days (range 116 - 181).

Here is a link to the full set of observations over the six days of the trip. It includes a small number of moths that I'd documented at home early on the first morning before I hit the road.
https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=any&subview=table&user_id=gcwarbler&verifiable=any
And here are links to my observations for the counties of some of the above destinations:
Mills Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=1714&user_id=gcwarbler&verifiable=any
Moore Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=888&user_id=gcwarbler&verifiable=any
Hartley County: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=1551&subview=table&user_id=gcwarbler&verifiable=any
Dallam Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=807&user_id=gcwarbler&verifiable=any
Hansford Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=2777&user_id=gcwarbler&verifiable=any
Gray Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=814&user_id=gcwarbler&verifiable=any
Briscoe Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=801&user_id=gcwarbler&verifiable=any
Coke Co.: https://www.inaturalist.org/observations?d1=2021-06-12&d2=2021-06-17&order=asc&order_by=observed_on&place_id=1770&user_id=gcwarbler&verifiable=any

So how does that compare to field days for you? I seem to recall that during one of the first City Nature Challenges I participated in for the Austin area—a five-day event at the time—I was uploading something on the order of 150 to 200 observations per day (you could check me on that). So this Panhandle trip was a roughly equivalent effort. That early CNC effort was exhausting. This Panhandle trip was steady and there was a lot of travel involved so the changes in location were as much responsible for the high number of observations as the diversity of plants and animals, per se.

I love taking these iNat trips. For me, documenting so many plants and animals cements in my memory the broader, diverse landscapes that I encounter during each journey. Among those thousands of photos, I do include any number of general “habitat” shots, but the encounters with this plant or that critter offer hundreds of “defining moments” that I can think back on. The trips and the subsequent research to identify all the plants and animals deepen the learning experiences. They are overt evidence of my old adage, “Travel is taxonomically broadening.”

Well, it took me a little over a month, but I've finally edited and uploaded the last of my images from our Guatemala journey in early January. Here's the whole set:
https://www.inaturalist.org/observations?place_id=6940&user_id=gcwarbler&verifiable=any
These are the product of sorting through about 1700 photos to compile just under 500 observations. By iNat's calculation, the effort documented about 343 species of plants and animals, but I'm not sure how that total is calculated for my Observations page. There is still a fairly large set of my observations left at genus, subfamily, family, or higher levels of classification. In many cases, of course, some plants and animals won't be ID-able better than genus or so, but that still leaves a lot that I haven't pinned down. If anyone has a desire to delve into those groups needing more work, here are some subsets of my observations that could use some help:

Flowering plants IDed no lower than tribe (currently 17 observations):
https://www.inaturalist.org/observations?hrank=kingdom&lrank=tribe&place_id=6940&taxon_id=47125&user_id=gcwarbler&verifiable=any

Insects with an ID no finer than tribe (about 84 observations; mostly moths, see next):
https://www.inaturalist.org/observations?hrank=kingdom&lrank=tribe&place_id=6940&taxon_id=47158&user_id=gcwarbler&verifiable=any

Moths IDed no finer than tribe (about 53 observations):
https://www.inaturalist.org/observations?hrank=kingdom&lrank=tribe&place_id=6940&taxon_id=47157&user_id=gcwarbler&verifiable=any

For a country with such incredibly rich biological diversity, Guatemala is in dire need of additional attention to document this diversity. My meager efforts on a 12-day visit now place me among the top dozen in observations and species out of some 3,000 iNat observers in Guatemala (local and visitors). To date, this most populous country of seven Central American nations has the 2nd lowest iNaturalist observer density (in terms of both population and area), 2nd lowest number of observations per 1000 sq. km. and the lowest number of observations per iNaturalist observer. There are obviously some difficult and complex socio-economic issues behind such numbers and I am in no position to analyze this further. That said, I have been encouraged by some of my Guatemalan friends to solicit further attention to this biological wonderland. I am certain I will be making a return visit to Guatemala in the not-too-distant future.

My wife and I enjoyed a relatively quick (12-day) getaway to Guatemala for a birding trip. Traveling, flying, or just being in public places in this continuing pandemic is particularly stressful, but we were traveling with a trusted group of Covid-vaccinated and tested friends and excellent local guides with a well-established itinerary. Aside from the two long and uncomfortable travel days (airports, planes, etc.), touring in Guatemala was very exciting and pleasurable.

Arranged through JB Journeys, our local guides were the incomparable (and surprisingly young) John Cahill and Josue de León L. Part of our stay was at the Community Cloud Forest Conservation (CCFC) in the highlands of central Guatemala, hosted by John’s parents, Rob and Tara Cahill. All of these folks are superb birders and naturalists. The work being done at CCFC is particularly inspiring; see the link below to their website for full details of their important efforts. One afternoon, I got a picture of John, Rob, Josue, and visiting friend Moises Rodriguez, who collectively constitute 4 of the 5 top eBirders in the country!
https://ebird.org/tx/region/GT/ebirders?yr=all&m=
My first upload from the trip is appropriately emblematic of the country and the journey:
https://www.inaturalist.org/observations/105035553
We saw two male Quetzals in beautiful cloud forest habitat. I ended up with a bird list of over 300 species, including at least 27 Life Birds. That latter number may be supplemented by some "heard only" species--some glimpsed briefly--that were new to me.

Perhaps most thrilling for me were a few encounters with over-wintering Golden-cheeked Warblers in cloud forest and humid pine-oak habitat in the highlands. In very real ways, those brief sightings rounded out my life-long studies and work with the Golden-cheeked Warbler. I certainly hope to spend more time with GCWAs on their winter range, but now their full life history story has so much more meaning to me personally, bringing it “full-circle” in an ecological sense. John even took us birding in the hills above the village of Tactic, presumably close to the spot where the Golden-cheeked was originally discovered by Osbert Salvin in 1859. We saw one of our Golden-cheeked Warblers close at hand, foraging in oaks in those hills. That gave me chills just thinking about the history involved in all of that.

I will have hundreds of iNat uploads of plants, insects, and a few more birds over the next several days and weeks. Stay tuned! Here are a some relevant links to information on the tour company, guides, and other Guatemalan information:
https://www.jbjourneys.com (our U.S.-based tour company)
https://xikanel.com (John Cahill’s tour company)
https://cloudforestconservation.org (CCFC; hosted by Rob and Tara Cahill)
https://www.hotelatitlan.com (4-star hotel for our first two nights)
http://www.hposadaquetzal.com (2 night’s stay in cloud forest)
http://www.tikalnationalpark.org (our last 2 days and nights. It’s Tikal; what more can I say!)
https://www.inaturalist.org/observations?place_id=6940 (all iNaturalist observations for Guatemala)
https://www.inaturalist.org/observations?place_id=6940&user_id=gcwarbler&verifiable=any (my Guatemala sightings—keep checking back)

Vitor O. Becker, a Lepidopterist in Brazil, just published a revision of the Noctuid genus Catabenoides in the J. Lep. Soc. (JLS 75(4):259-279, Dec. 2021). The paper substantially revises the taxonomy of the genus including some important corrected synonymy. He also describes nine new species from South America. The paper affects species occurring in Texas.

From Becker’s research, two species of Catabenoides occur in Texas, C. vitrinus and C. divisa. This is where the synonomy gets complicated. Most previous records in this genus in Texas and the Southwest were assigned to C. terminellus (with synonym C. candida)(iNat, MPG, BG, etc.). Becker synonymizes terminellus, candida, and a Florida species insularis under C. divisa. His expanded concept of divisa ranges from the British Virgin Islands, through Puerto Rico, Hispaniola, and Cuba, to south Florida, and from Texas to Arizona south into Mexico.

Importantly, Becker also offers an expanded concept of C. vitrinus, stating that it is “sympatric throughout” the range of divisa, and not just confined to Florida and the Caribbean as indicated in other sources (e.g. MPG). He maps vitrinus from Hispaniola, Jamaica, and south Florida, as well as from Texas and Arizona south into Mexico.

Taking his concepts of vitrinus and divisa at face value, the issue facing us in Texas is where each occurs and how we might tell them apart. A distribution map in Becker’s paper is unfortunately flawed and certainly incomplete. He indicates he examined 11 Texas specimens of vitrinus (but no genitalic slides) and 24 Texas specimens of divisa (including 3 genitalic slides). His map (Fig. 31, p. 264) has some misplaced symbols for divisa so it is somewhat unreliable for a detailed examination of the ranges. That said, if we take as a starting point that both species occur and overlap broadly in Texas, his map suggests that both species occur in South Texas and the Hill Country. He lists records of divisa in the Trans-Pecos but none there for vitrinus.

Here is another case where the utility of iNaturalist could be demonstrated: iNat presently contains 314 observations of this genus in Texas including at least 216 Research Grade observations (all RG assigned to “terminellus”). We have accumulated records of the genus as far north as I-20 in such locations as Palo Pinto SP, Maddin Prairie, Big Spring, and Midland. The challenge now is to be able to distinguish and assign photographic observations to one or the other of Becker’s species. It will not be possilbe to put a species name on all of them. But Becker offers one little tidbit which might help distinguish the two in photos:

The patagia are the “epaulets” which flank the middle of the thorax on most moths. On C. vitrinus, there is a “diffuse ochreous [pale orange] line across the middle of the patagia”, whereas in divisa there is a thin black line in the middle of the patagia. These marks might be tricky to see in dorsal views, but can be judged in clear lateral views of unworn moths. The primary image of “Catabenoides vitrina” on MPG shows the dull orange on the patagia:
http://mothphotographersgroup.msstate.edu/species.php?hodges=10036
Here is an example of mine (dorsal view) at Timberlake Biologocal Station (Mills County) from October 2019 which seems to show the diffuse dull orange color on the patagia which would place this in the revised vitrinus:
https://www.inaturalist.org/observations/34161132
Note that the long black stripe on the FWs is not related to species discrimination; it is found on females of both species, absent on males of both species.
But another of my examples from Timberlake seems to show both a dull orange color and a thin dark line on the patagia:
https://www.inaturalist.org/observations/34161133 (2nd image)
So it is not going to be easy to separate these two in Texas.

I am NOT going to attempt reidentifying a lot of Catabenoides in Texas just yet. For one thing, “Catabenoides divisa” isn’t in the iNat taxonomy. For another, Jim Troubridge and other researchers may still have different concepts of the species of Catabenoides occurring in the U.S. So as informative as Becker’s brand new paper is, it may not be the final word.

If you want to dive into this further, here is a link to all 314 observations of Catabenoides in Texas on iNat:
https://www.inaturalist.org/observations?place_id=18&taxon_id=330406
and on BugGuide (total 55 images but none assigned to vitrinus):
https://bugguide.net/node/view/169895/bgimage?from=0

I am in the process of compiling an ID guide for a set of small buffy brown moths that have upturned palpi (thus all in the Gelechioidea superfamily), forewings that are oval to oblong, more or less flat-winged resting posture, and a few dark dots on the forewings. I myself and many of my iNat friends in Texas have been struggling with keeping several of these straight. This will be a Texas-centric list but it should have wider application in the south-central U.S. Below I list the set of about 20 species and genera which I intend to cover, but I would like anyone interested in this topic to chime in with anything else that might need addressing in this small confusing corner of mothdom. Those that are easier to distinguish and will be dealt with only briefly are marked with “(E)” for "easy"….which they are NOT, but they can be readily separated from the rest of the set:

AUTOSTICHIDAE
Autosticha kyotensis - Kyoto Moth
https://www.inaturalist.org/taxa/214687-Autosticha-kyotensis

Glyphidocera juniperella - Juniper Tip Moth
https://www.inaturalist.org/taxa/333290-Glyphidocera-juniperella

Glyphidocera democratica - “Democratic Moth”?
https://www.inaturalist.org/taxa/416888-Glyphidocera-democratica

Glyphidocera dimorphella
https://www.inaturalist.org/taxa/416886-Glyphidocera-dimorphella

DEPRESSARIIDAE
Agonopterix spp. (E)
https://www.inaturalist.org/taxa/126363-Agonopterix

Antaeotricha haesitans (E)
https://www.inaturalist.org/taxa/840127-Antaeotricha-haesitans

Antaetricha osseella
https://www.inaturalist.org/taxa/416874-Antaeotricha-osseella

Antaeotricha unipunctella
https://www.inaturalist.org/taxa/325988-Antaeotricha-unipunctella

Durrantia piperatella (E)
https://www.inaturalist.org/taxa/490824-Durrantia-piperatella

Exaeretia sordidella (E - Doesn’t occur in TX)
https://www.inaturalist.org/taxa/504378-Exaeretia-sordidella

Gonioterma mistrella
https://www.inaturalist.org/taxa/220538-Gonioterma-mistrella

Machimia tentoriferella - Gold-striped Leaftier (E - not documented in TX yet)
https://www.inaturalist.org/taxa/81689-Machimia-tentoriferella

Psilocorsis cryptolechiella - Black-fringed Leaftier (E)
https://www.inaturalist.org/taxa/229229-Psilocorsis-cryptolechiella

Psilocorsis quercicella - Oak Leaftier
https://www.inaturalist.org/taxa/229230-Psilocorsis-quercicella

Psilocorsis reflexella - Dotted Leaftier
https://www.inaturalist.org/taxa/147992-Psilocorsis-reflexella

GELECHIIDAE
Anacampsis and Dichomeris spp. (E - most are not confusable with LBJs)

Dichomeris georgiella
https://www.inaturalist.org/taxa/416950-Dichomeris-georgiella

Deltophora sella (E) - Black-spotted Twirler
https://www.inaturalist.org/taxa/324643-Deltophora-sella

Helcystogramma spp. (E) (3 spp to consider)
https://www.inaturalist.org/taxa/177977-Helcystogramma

OECOPHORIDAE
Inga cretacea - Chalky Inga (E)
https://www.inaturalist.org/taxa/324605-Inga-cretacea

Inga obscuromaculella
https://www.inaturalist.org/taxa/518250-Inga-obscuromaculella

Please leave a comment, or message me directly if you have other suggestions. Thanks for any input.

Abstract: A newly-discovered population of the non-native Ruellia dipteracanthus probably had its origin as hidden rootstock in a gallon-container of a different wetland plant purchased at a local nursery. In the three years since its apparent planting, the species has become well-established in the immediate area. Efforts to remove the species have been initiated.

On 31 August 2021, I found a small population of the non-native Ruellia dipteracanthus (Nees) Hemsl. in the creek bed near my house on Salton Drive, Austin, TX.
https://www.inaturalist.org/observations/93431167
@centratex was the first to suggest this ID and it was subsequently confirmed by @eric_keith. This was the 2nd report of the species in the Austin area and the 3rd Texas location of this potentially invasive species (Keith et al. 2017). The species is native to Brazil and established in the wild in Mexico (Mowat 2017, Nees 1847, cited in Keith et al. 2017). I had not previously noticed the species even through I work regularly in this stretch of the creek bed removing other invasive species such as Ligustrum spp. and Chinese Tallow Trees (Triadica sebifera). Another non-native species, Mexican Ruellia (R. simplex) is common along the creek banks in this watershed, and it was only because I noticed a difference in flower color, leaf shape, and pubescence that I realized it was something different (and non-native). The clusters of R. dipteracanthus are in a mixed native herbaceous groundcover on a sand and gravel bar just a foot or so above the level of the adjacent perennial creek.

I wondered about the origin of this non-native species and expected that the source would be from some suburban yard in the watershed upstream of the location of the plants. On 4-5 September 2021, I criss-crossed the neighborhood streets flanking this reach of the creek, studying flower beds in the front yards of homes in the area. I covered an area of about 65 acres (26 hectares) including most of the immediate watershed of the creek as far as 0.5 mi (0.85 km) upstream of the population of plants. This is only a small portion of the 500-acre watershed upstream of the plants, but I found no other plantings of the species.

Returning to the plants with the intent of collecting a few voucher specimens, I noticed that the clusters of the species were in the same area as some Smooth Horsetail (Equisetum laevigatum) that I had planted on the creek bank about 3 years prior.
https://www.inaturalist.org/observations/93802354
Then it dawned on me: The new Ruellia plants were almost perfectly coincident with those clusters of horsetails, with just a few small clusters immediately downstream where they had probably recently spread. My theory now is that even though I had only purchased one 1-gallon container of horsetails to plant, the pot may have contained some unnoticed rootstock of R. dipteracanthus, and thus I inadvertently planted both species at the site. Moreover, I had split up the horsetails into about 3 or 4 small clusters to plant in an area of about 10 m x 20 m, and each of those horsetail clusters now has a vigorous associated colony of the Ruellia.

That realization changed my goal: I immediately made plans to begin the process of removing the non-native Ruellia from the location. In that effort, I soon found that the species grows in dense clusters with vigorous rhizomes, a deep root system, and that stems bent over by floodwater were also commonly rooting at the nodes. Aboveground stems easily broke off at ground level nodes, a strategy which would benefit the plants and make them efficient colonizers under disturbance regimes like flood events.
https://www.inaturalist.org/observations/93802355
The effort to remove the easily reachable clusters of plants will take several days of digging in the sand, gravel, and cobble of the creek bed. It is likely that regrowth of some plants will occur in future growing seasons and that retreatment and vigilance will be necessary to ensure that all material has been removed. This is not a new type of effort for me. I previous undertook the removal of invasive Elephant Ears or Taro (Colocasia esculenta—not originating from me!) along this same stretch of creek and that effort took a few years to complete and requires continuing monitoring.
https://www.inaturalist.org/observations/1914012
https://www.inaturalist.org/observations/19376164
https://www.inaturalist.org/observations/19686222
https://www.inaturalist.org/observations/2116918

References:

Keith, E., J. Wright, and W. Godwin. 2017. Naturalized occurrence of Ruellia dipteracanthus (Acanthaceae) in the USA. Phytoneuron 2017-57:1-3.