February 22, 2024

Annotated Checklist of Texas Endemic Plants (2009)

There is a annotated list of Texas endemic plants on Guy Nesom's website, a draft made by botanist Bill Carr in 2009. It might be a bit dated, but I nonetheless found it interesting to read and it might prove useful to reference in the future.

Carr. W. R. (2009) "No place but Texas: An annotated list of plant taxa endemic to the Lone Star state." The Nature Conservancy of Texas. https://www.guynesom.com/Texendemicsweb.htm.

The list includes everything at the specific level and below.

Posted on February 22, 2024 05:32 AM by arnanthescout arnanthescout | 0 comments | Leave a comment

January 22, 2024

Silvics of North America (1990) Online

Silvics of North America is a handbook published by the US Forest Service which describes ~200 species of trees. It has detailed information on habitat (substrate and climate preferences), life history, associated forest cover, uses... just, a lot. It also has sources tracked down to the sentence, so you can trace the information back to the literature. While published in 1990 and perhaps be more than 30 years old, there is nonetheless a lot of useful information to be sought here.

The entire book can be found online and free to the public here: https://www.srs.fs.usda.gov/pubs/misc/ag_654/table_of_contents.htm

It is divided into two volumes, one on conifers and the other on hardwoods. While you are unlikely to find every species of tree on here, any that are covered will have a treasure-trove of information. You can also download PDFs of the volumes as well. Good for anyone ranging from the curious plant enthusiast to the experienced forester.

Sample entry from book on Quercus stellata

Posted on January 22, 2024 10:04 PM by arnanthescout arnanthescout | 0 comments | Leave a comment

January 13, 2024

Saltmarsh Asters (Symphyotrichum divaricatum and Symphyotrichum subulatum) in Texas

Subgenus Astropolium in Symphyotrichum contains our Saltmarsh asters, as they are called. They're pretty easy to recognize: reduced, narrow stem leaves around the flowers that are pressed against the stem; glabrous or nearly glabrous stems and leaves; a dispersed out, paniculate arrangement of flowers. Currently three species seem to be recognized:

  • Perennial Saltmarsh Aster, Symphyotrichum tenuifolium
  • Southwestern Annual Saltmarsh Aster, Symphyotrichum expansum
  • Annual Saltmarsh Aster, Symphyotrichum subulatum
  • Southern Annual Saltmarsh Aster, Symphyotrichum divaricatum

These last two are the ones I am focusing on (though I will briefly go over the 2nd species). I feel like there is a bit a confusion regarding these two species—likely due to their taxonomic history—and want to clear that up a bit.


Too Long, Didn't Read?

In a nutshell: While Symphyotrichum divaricatum is widespread throughout Texas on a variety of habitats, Symphyotrichum subulatum only occurs in the far southeast corner of the state and only in saline locations—salt marshes, tidal flats, and sometimes along salted highways. This means that unless you have a plant in one of those habitats, I'd argue it's almost guaranteed that your Saltmarsh aster is Symphyotrichum divaricatum and not S. subulatum, particularly if it's growing in a weedy lawn or disturbed area.

There are ways to distinguish the two morphologically through flower arrangement and phyllary details, but in my opinion, location and habitat should be suitable for IDing S. divaricatum for the vast majority of observations in Texas. Where things may be more difficult are places where a third species, S. expansum, occurs alongside S. divaricatum because of overlap in range, ecological niche, and intermediate individuals (appearing to be a mix of both) - this overlap is mostly restricted in West Texas (see BONAP map, which appears accurate for this species). I ultimately leave it up to the iNaturalist community to decide how to tackle these observations.


Brief Taxonomic Background

In short, Symphyotrichum divaricatum was once considered a variety of Symphyotrichum subulatum, known as Symphyotrichum subulatum var. ligulatum, and is treated as such in Flora of North America and many older publications. However, recent work by Guy L. Nesom (2005) split the varieties into their own species, and this has largely been accepted by the botanical community, as can be seen the draft treatment for the East Texas Asteraceae for the in-production Flora of East Texas.

The reasons for this are explained clearly in the Flora of North America discussion under S. subulatum:

  • The geographic range of the varieties barely overlap—"nearly allopatric" is the term used.
  • The varieties are "mostly reproductively isolated:" while intermediates (individuals with characteristics in-between both varieties) occur in areas where varieties overlap, experiments by S. D. Sundberg (1986) found that hybrid individuals are mostly sterile and unable to produce viable offspring.
  • Differences in morphology and ecology.

S. subulatum, S. divaricatum, and S. expansum are the three species occurring in Texas resulting from this taxonomic change:

  • Symphyotrichum subulatum var. ligulatum, >>> Symphyotrichum divaricatum - Southern annual saltmarsh aster
  • Symphyotrichum subulatum var. subulatum, >>> Symphyotrichum subulatum - Annual saltmarsh aster
  • Symphyotrichum subulatum var. parviflorum >>> Symphyotrichum expansum - Southwestern annual saltmarsh aster

Such differences will become clear soon when I go over these two species.


Geographic and Ecological Isolation

The range of S. divaricatum and S. subulatum overlap... but barely. To bring this point, go to the East Texas Asteraceae draft, and then find the county-level maps for both species (page 189 & 191). If you do, you will find the following:

  • S. divaricatum: Widespread through all of Texas.
  • S. subulatum: In 4 counties on the far southeast corner of the state.

The third former S. subulatum variety, S. expansum, overlaps slightly with S. divaricatum in West Texas. Putative intermediates have been found in that overlap region.

The two species are well-separated ecologically as well. In the East Texas Asteraceae draft, S. subulatum is "restricted to salt marshes and tidal flats of the Gulf Coast." S. divaricatum on the other hand is less picky, growing in moist areas, disturbed sites, and often weedy lawns—but does not grow in saturated, salty locations. Thus, if one finds a Saltmarsh Aster in a weedy lawn it is almost certainly S. divaricatum and not S. subulatum.

Left shows S. divaricatum in disturbed, weedy area. Right shows S. subulatum in saltmarsh habitat. Images from https://www.inaturalist.org/observations/195684456 and https://www.inaturalist.org/observations/16450259

S. divaricatum in low-cut lawn. This species tolerates mowing well, even adjusting to flower at the mow line! Image from https://www.inaturalist.org/observations/98241703

Flora of North America notes that S. subulatum (treated at variety level) has been known to occur inland in "salted habitats" around the Great Lakes, listing "brackish marshes" and "salted highways" among possible habitat. It is possible that seeds of S. subulatum from the coast could be deposited deeper inland in Texas given in lands in suitable saline habitat, similar to occurrences in Michigan or Ohio—something to keep in mind.


Differentiation of Species Morphologically

In the Flora of East Texas draft, the two species are distinguished morphologically in two different ways: the arrangement of the flowers (inflorescence structure) and the phyllaries.

Symphyotrichum subulatum has its heads arranged in a dense, pyramidal array, with flowers grouped close together:

See more specimens images here.
I would say that "dense" is a relative term here: the flowers are still spread out, and on the lower branches of the pyramid are further spaced apart. The inflorescence is most dense towards the top of the pyramid.

"Dense" is thus relative to Symphyotrichum divaricatum, which has its heads in a very diffuse, open arrangement. Notice the vast amounts of negative space between the flowers compared to the previous species:

See more specimen images here.

At its most crazy, S. divaricatum flowers can be so spread out that they almost seem to float in midair.

Of course, if the plants get cut or mowed back the flowering arrangement will look different (maybe even doing the "flower from the mow-line" party trick). But as previously mentioned, any plant in a disturbed or weedy area in Texas is almost certainly going to be S. divaricatum.

I will note that the inflorescence arrangement can be variable and might be ambiguous on occasions.

The other method, using phyllaries, is confounding to me and I have been unable to see it reliably. The first part refers to the green zone on the phyllaries. On S. divaricatum (left image) the green zone extends the entire length of the phyllaries; on S. subulatum (right image) the green zone is restricted to the upper portion.

These were the two most clear-cut examples I could find, from observations that I carefully assessed were ID'd correctly. In most other observations and pressed specimens, it was incredibly difficult to see any real difference at all. Images from https://www.inaturalist.org/observations/98435941 and https://www.inaturalist.org/observations/138267257

Then there is the note on "hardened bases." As of me writing this (January 2023) I have yet to figure out what exactly this means. What is hardened about the phyllaries on S. divaricatum? What does it mean if the phyllaries are not hardened like in S. subulatum? Maybe a more thorough review of the literature will yield more information on this, but until then I remain confounded on how to use this character.


Conclusion

The ultimate purpose of this journal post is mainly to clarify the situation between Symphyotrichum divaricatum and S. subulatum, which seem to cause a lot of confusion at least in Texas. My personal opinion is that the vast majority of Saltmarsh asters observations in Texas can be accurately identified as Symphyotrichum divaricatum based on location and habitat; after all, throughout most of Texas it is virtually the only Saltmarsh aster species present.

I do feel that for S. subulatum, habitat alone may not enough, because its range overlaps with S. divaricatum (even if they are said to occupy different ecological niches); for a species ID I would suggest at least a photo showing the pyramidal inflorescence structure to help confirm the identity of the plant. Certain plants would likely require more scrutinization for ID,

There is the possibility of mistakingly marking S. subulatum as S. divaricatum for individuals that sneak further inland in suitable habitat e.g. saline marsh areas, salted highway roadsides and ditches. However, the current situation with Saltmarsh asters in Texas is likely not better, just due to general lack of knowledge along with the close similarity between these species.

I have also neglected to look in-depth at Symphyotrichum expansum. Things may be more difficult where Symphyotrichum expansum occurs alongside S. divaricatum due to overlap in range, ecological niche, and intermediate individuals (plants appearing to be a mix of both). This overlap is mostly restricted in West Texas (see BONAP map, which appears quite accurate for this species).

While I have made my position regarding these plants clear in the previous paragraphs, I ultimately leave it up to the iNaturalist community to decide how to tackle these observations. And for those seeking a better understanding of these two species and how to photograph and identify them—I hope this is informative and useful to you.


Consulted Literature

Brouillet, L. et al. Symphyotrichum subg. *Astropolium. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 25+ vols. New York and Oxford. Vol. 20. http://floranorthamerica.org/Symphyotrichum_subg._Astropolium.

Brouillet, L. et al. Symphyotrichum subulatum. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 25+ vols. New York and Oxford. Vol. 20. http://floranorthamerica.org/Symphyotrichum_subulatum.

Brouillet, L. et al. Symphyotrichum subulatum var. subulatum. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 25+ vols. New York and Oxford. Vol. 20. http://floranorthamerica.org/Symphyotrichum_subulatum_var_subulatum.

Brouillet, L. et al. Symphyotrichum subulatum var. ligulatum. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 25+ vols. New York and Oxford. Vol. 20. http://floranorthamerica.org/Symphyotrichum_subulatum_var_ligulatum.

Carr, W. R. (2008+). Travis County Flora Project. Archived version: http://web.archive.org/web/20220404171225/https://npsot.org/Austin/TravisCountyFlora/Travis%20County%20Flora.html

Neill A. K., contributor (2019). Asteraceae of East Texas. For Diggs et al. Illustrated Flora of East Texas series. Botanical Research Institute of Texas Press. https://fwbg.org/wp-content/uploads/2021/08/Asteraceae_East_Texas_download.pdf.

Nesom, G. L. (2005). TAXONOMY OF THE SYMPHYOTRICHUM (ASTER) SUBULATUM GROUP AND SYMPHYOTRICHUM (ASTER) TENUIFOLIUM (ASTERACEAE: ASTEREAE). SIDA, Contributions to Botany, 21(4), 2125–2140. http://www.jstor.org/stable/41968509

Sundberg, S. D. (2004). NEW COMBINATIONS IN NORTH AMERICAN SYMPHYOTRICHUM SUBGENUS ASTROPOLIUM (ASTERACEAE: ASTEREAE). SIDA, Contributions to Botany, 21(2), 903–910. http://www.jstor.org/stable/41968346









Posted on January 13, 2024 05:53 AM by arnanthescout arnanthescout | 6 comments | Leave a comment

December 28, 2023

Running List of Grass Resources

This is a live document. I will keep updating and revising this page as I find new resources and continue to explore/use them.

Jim Conrad's Naturalist Newsletter
https://www.backyardnature.net/n/grasses.htm
An excellent starting point for those starting out with grasses. Species entries are oriented towards field identification and more geared towards a general audience, and thus easier to read.

Jim also notes the patterns among genera and groups of grasses. Learning the field marks for these subgroups is a lot easier than trying to recognize each species individually, which is why personally I started by trying to recognize grass genera rather than individual species, although many of the common species can be learned along the way.

Plants of Texas Rangelands - Grasses
https://rangeplants.tamu.edu/collection/grasses/
Has profiles on many grasses with a brief description, but also useful information habitat, ecology, and forage value for livestock and wildlife. Taken from "Know Your Grasses" book.

USDA Forest Service - Fire Effects Information System
https://www.feis-crs.org/feis/
https://www.feis-crs.org/feis/faces/SearchByOther.xhtml
Has species profiles for a lot of grass species across the United States. Detailed information given on habitat types, associated plant species/communities, ecosystem/cover types, wildlife and livestock use, forage value and useful information for range management, just a LOT of very, very useful information. It also has sources cited as well, so you can trace the information back to their sources! Also not just limited to grasses but rather includes wildlife in general.

You won't find every grass species on here, (for example Eastern gamagrass and Silver bluestem are oddly missing), but if it does have a profile... jackpot of information.
https://www.fs.usda.gov/database/feis/AboutFEIS/about.html

Alred, K W (1982). "Describing the Grass Inflorescence."
The best paper I have found to explain grass inflorescence terminology so far. The pictograms on page 674 + "Proposed Terminology for the Grass Inflorescence" section I found particularly useful.

The pdf to the paper can be found in various sites but I found it first here:
https://www.poison.org/-/media/files/pdf-for-article-dowloads-and-refs/allred-describing-the-grass-inflorescence.pdf

Flora of North America (FNA)
http://floranorthamerica.org/Poaceae
Poaceae is treated in Flora of North America, so you can find a detailed description for just about every single grass species within the Continental United States and Canada. The generic keys are excellent too; I typically will use them to single out differences between a few chosen species, though I prefer using my more regional Flora of North Central Texas for keying plants out. But the illustrations are a lifesaver; they have close-ups of spikelets and florets with just about everything you could ever want labeled. I refer to them frequently alongside the descriptions, or in conjunction with a regional flora.

You will generally find the illustrations either on the species pages or in the infraspecific taxa (subspecies, varieties). If missing, then check the pages for the subspecies or varieties.

International Seed Morphology Association
Did not know this existed, but worth checking out. Despite the name, they have photographs of spikelets as well! Used in conjunction with technical descriptions, they could be useful.

The link below leads to a very detailed and slightly overwhelming page covering variation in grass spikelet structure.
https://seedidguide.idseed.org/familles-de-plantes/grass-spikelet-structures-of-diagnostic-value/

Posted on December 28, 2023 07:00 PM by arnanthescout arnanthescout | 0 comments | Leave a comment

December 17, 2023

Speedwells are Back! Distinguishing Bird's-eye Speedwell and Grey Field-speedwell (Veronica persica vs Veronica polita)

Winter is just about here, which means cooler, wetter weather... and the speedwells are along for the ride.

I've seen 6 species of Veronica around Austin, and while all but one (Veronica peregrina, the purslane speedwell) are non-native, the other species are thankfully not invasive and largely restricted to disturbed sites. Their petite little flowers bloom even through the cold of winter, quickly bouncing back even after ice and frost. It seems their flowering season (in Texas at least) starts in late fall, around November or December, increasing their flowering output through January and February and into the peak of spring, before fading with the heat of summer. While others may regard them as little more than lawn weeds, their microblooms bring a little joy to my heart, a much-needed morale-boost for the overwintering botanist.

Most commonly seen is the Bird's-eye speedwell (Veronica persica), which I suppose given enough imagination could appear like a bird's eye. It can however be easily confused with a very similar-looking species that is much less observed in Texas, the Grey field-speedwell (Veronica polita).

Case-in-point: As of me writing this post there are just over 3,000 observations of Bird's-eye speedwell. Meanwhile, there are just over 600 observations of Grey field-speedwell. That's five-times less than the former species.

We are fortunate to have the taxonomic authority on speedwells on iNaturalist, Prof. Dirk C. Albach, who authored the Flora of North America treatments for the genus. I humbly owe most (if not all) of my information on distinguishing these species from him. Drawing from comments he has made on previous observations, you can reliably distinguish the two species... if you know what to look for.


Field Identification Notes between Bird's-eye Speedwell (Veronica persica) and Grey Field-speedwell (Veronica polita)

Photos for best shot of ID

  • Front photo of flower.
  • Back photo of flower to see the sepals
  • Photos of the fruit

The other two are not as easy to capture but I give details and advice on photographing them in later sections.

Example observations:
https://www.inaturalist.org/observations/196550220) for an ideal example
https://www.inaturalist.org/observations/109845925 with less "fancy" photos, but just as IDable as the first

Corolla lobe/petal overlap

The four petals of Bird's-eye speedwell tend to overlap, particularly the two lateral petals with the posterior petals (left image). Those of Grey field-speedwell don't tend to overlap, often to the point where there can be a narrow gap between the petals (right image).

In both images, the flowers are right-side up. The top petal is the anterior petal, the paler bottom one the posterior petal, and the two middle petals on the left and right side are the lateral petals. In general it seems the anterior petal is most strongly pigmented blue, while the posterior petal is the palest, which helps with determining which is which. Note also the the posterior petal is often noticeably less wide than the other 3 petals.

Sepal width relative to the petals

Grey field-speedwell has broad, ovate sepals, which are about as wide as the petals. Those of Bird's-eye speedwell are narrowly elliptical, particularly when compared to the petals.

The sepal width difference trait can be used on very young fruit, where the flowers have fallen away and the fruit is just starting to develop (and young fruit are often unintentionally captured in the background of photos). On more mature fruits, the persistent sepals appear to enlarge and it becomes difficult to tell. The easiest way to see the difference, in my opinion, is to flip the flower over and get the backside:

Left is Bird's-eye speedwell, right is Grey field-speedwell. You can see quite clearly that the petal on Bird's-eye speedwell is much broader than the sepal underneath. Note how on the Bird's-eye speedwell, you can easily fit the sepal inside the lateral petal—it's that much smaller. Meanwhile on the Grey field-speedwell, the sepals could easily cover most, if not all, of the petals, if aligned right.

Generally this is most obvious in comparison with the lateral and anterior petals, since the posterior petal is often reduced and so often closer in width to the sepals.

This characteristic is the most obvious to me and seems fairly easy to capture; either bend the flower so that the back is visible, or pluck one off altogether and plant it face-down for photographing. Sometimes it helps to pluck off the top set of leaves near the flowers if they obscure the sepals when bending the flower over.

Another sepal characteristic that has been used the relative length of the sepals compared to the flowers. In Grey field-speedwell, the sepals are often long enough that they poke out prominently from behind the petals; in Bird's-eye speedwell, the sepals are less long relative to the petals and only the apices of the sepals stick out from behind the petals. This seems to work fairly well in cases when the sepals are mostly hidden behind the petals (in which case those are very likely Bird's-eye speedwell), but occasionally you may find a Bird's-eye speedwell with the sepals showing-off more and extending beyond the petals like Grey field-speedwell, which adds some ambiguity. Thus, I prefer relying on sepal width relative to the petals.

Fruit shape

Getting updated...

The shape of the fruits are noticeably different between these two species.

For both species, the fruit has two lobes with a indent in the middle, the sinus. The fruit for Birds'-eye speedwell (at left) has lobes that are divergent from each other, with a wide sinus angle. The fruit for Grey field-speedwell (at right) has lobes that appear tighter, with a smaller, narrower sinus.


Bird's-eye speedwell is on the left and Grey field-speedwell is on the right.

If you've found a speedwell in bloom, it's likely that they have fruit on them! Look for older plants, then follow down the stems away from where the flowers are.

Speedwell stems with fruit on them. Notice how they get larger and more mature as they go down the stem.

The characteristic used in Flora of North America to distinguish the two species is through the fruit as well, although not as clear to the eye. The fruiting capsules of Veronica have two main lobes, and in-between the lobes is a little indent or "sinus." For Bird's-eye speedwell the sinus is deep, with a typical sinus angle ranging from 90–120 degrees. The sinus in Grey-field speedwell is shallow with an typical sinus angle ranging of 20–60 degrees.


Grey field-speedwell seems to be under-documented in Texas, probably because of its close similarity to the more commonly-observed Bird's-eye speedwell, and perhaps its smaller corolla size. I hope this post clears up any confusion regarding the two species, help observers better document the less common of the two, and perhaps bring a little more attention to these petite microflowers as they say, "wait a little, wait a little longer—spring will be coming."


Observations referenced:
https://www.inaturalist.org/observations/39519276
https://www.inaturalist.org/observations/71076202

Posted on December 17, 2023 12:47 AM by arnanthescout arnanthescout | 6 comments | Leave a comment

December 07, 2023

I am one with the Ligule League

Yes, I have become a grass person now.

On this forsaken day, I, Arnan Pawawongsak, declare my allegiance to the GRAMINOID SIDE 🌾😈🌾

Long I have resisted the power of the grasses, but all that changed during my REU this summer, when I obtained a whiff of blueberry scones from Silver bluestem, at Matador Wildlife Management Area (credit to wildlife biologist Hunter Hopkins for the tip-off).

All it took was one brief perusal of Gould's grass tome, one Plant Systematics class, and several trips to the Wildflower Center vegetation survey to learn the Dark Arts from Sean and Michelle... my fate was sealed.

I know several genera and some common species, but I'm learning fast. Never before have I experienced this power... resistance is futile. FEAR ME, NON-GRASS PEOPLE!!!

Ok, that was a bit over-dramatic. But the point has been made.

To be completely honest, all it took for me was the smell. Blueberry scones. Similar to how I got into trees, that was ponderosa pine. Although the tree hand-shaking episode played a big part too.


It all started when I was doing field work this summer for my REU with Dr. Charles H. Cannon and Claire Henley, on the last day of June, 2023. The wildlife biologist at Matador Wildlife Management Area, Hunter Hopkins (who kindly took us around the property and allowed us to sample the oaks) happened to mention this grass trivia as an aside, while we were working on a post oak-ish tree by the creek (which is also Hunter’s favorite tree).


The oak tree where it all started.

I didn't believe him at first. So naturally, I took a bunch of seed heads from one of the grasses, rubbed it between my fingers, and gave it a whiff.

Oh, wow. He's actually got a point.

The scent was sweet, a pleasant sweetness. Nothing you'd expect from such a humble-looking grass. The moment I got a whiff of that Silver bluestem, I was sold.


The ligule-leaved, spikelet-covered culprit. Actually, this isn't the one I smelled—I unfortunately did not capture that individual on camera. But this one was a nice looking Silver bluestem.

...Hunter actually didn’t say blueberry scones, it was some sort-of candy (SMARTIES candy?), but I personally found it smelled like blueberry scones. So that stuck.

Silver Bluestem, Silver Beard Grass, *Botriochloa laguroides* var. *torreyana*, synonym *Bothriochloa torreyana*, plant of many names... now and forever you will conjure the thought of freshly-baked blueberry scones.

And if you can't tell, I love blueberry scones.


Special thanks to Hunter Hopkins, wildlife biologist at Matador Wildlife Management Area, for tipping me off about the Silver bluestem thing; Dr. Robert K Jansen, professor at UT Austin, for going over grass morphology and Poaceae in Plant Systematics class; Frank W. Gould, for writing the Guide to Texas Grasses; Michelle Bertleson and Sean Griffin with the Science and Conservation team, for teaching me basic grass ID at the Wildflower Center, and; prairie_rambler or Cleveland Powell, iNaturalist grass master, for IDing my grasses and making sure that if I make any learning mistakes, they get corrected.

I would also like to thank the Flora of North America project contributors for their excellent labeled grass illustrations, which helps you figure out whether that bract you're looking at is a glume or a lemma, and Kelly Wayne Allred for writing the excellent article "Describing the Grass Inflorescence" back in 1982. Both have been very useful for learning and applying technical grass terminology.

Ligule League it is!

Posted on December 07, 2023 03:47 PM by arnanthescout arnanthescout | 2 observations | 2 comments | Leave a comment

November 21, 2023

Fox squirrel shows addiction to mealy oak galls

14 October 2023, around 9 AM
UT Austin Campus, on boardwalk at the SW corner of RLP (Robert L. Patton Building). Cloudy day.

I was working on some class work before Genetics, and couldn't help but notice that every few seconds, a little thing fell from the live oak tree above me. They fell frequently, though at irregularly intervals from each other. It was almost comedic how each one tumbled off from the branches above, landing with a audible thud on the wooden planks before bouncing a few times more, before then rolling away to a stop on the planks or off into the adjacent landscaping.

While these projectiles from the sky likely posed no threat of injury to myself—unless perhaps I took one to the eye—I was rather uncomfortable about continuing my work with the possibility of one of these falling on my head. But what were they? Initially I thought they might be acorns, but I didn't think that acorns would fall so frequently from the tree. I investigated one of the fallen projectiles, and noted that they were mealy oak galls.

I further noted that every single one of these projectile galls were half gnawed open. A quick visual search into the canopy of the live oak revealed the culprit: a fox squirrel.

Peculiarly enough, the squirrel seemed to have an addiction to these little galls. It would clamber its way to a branch with the galls, and then systematical rip each gall off the tree, gnaw on it for a second or two, and then promptly discard the half-gnawed piece to grab another gall, leading to the fiasco below.

Each piece I observed was gnawed such that the gall was chewed with the middle cavity exposed, but with the larvae inside missing. My presumption is that the squirrel was consuming the larvae inside each gall. I have not observed this behavior before but would be interested to hear if anyone else has.

Bad video:
https://youtu.be/R09A47S7yhI

Posted on November 21, 2023 12:20 AM by arnanthescout arnanthescout | 1 observation | 0 comments | Leave a comment

November 15, 2023

Seeps, Stairs, and Obi-wan conobea

I have long noticed that on the east side of UT Tower, there is a spot on the granite stairs leading up towards the xeriscape area that seems continually to leak water, running across the pavement and down the stairs.

At first I thought it was some leak from pipes underneath the building, but eventually I've come to believe that it is in fact a natural seep.
Seeps are places where water naturally oozes out of the ground. The City of Austin has a handout on seeps, which I'll quote:

https://www.austintexas.gov/sites/default/files/files/Watershed/Austin-Guides/AGT-Urban-Seeps.pdf

Seeps may conjure images of dripping, moss-laden rocks along cliffs in a forest. But seeps can be a common occurrence in urban areas as well. Water moves through natural and urban landscapes below the surface, unseen until it is forced out of the ground by things like bedrock or impervious clay. When this happens, it creates a seep.

This is what I assume is happening here. Water takes the path of least resistance. My interpretation is that the water was flowing underground through some porous material—maybe loose construction gravel or sand, maybe something else—when it hit something impenetrable underneath, causing the water to leap to the surface. It seems that around Austin, the underlying geology (limestone, karstic features, clay and river alluvium/deposits) makes the area a prime place for seeps to occur. The handout previously mentioned lists a few geologic formations in the Austin area which create ripe conditions for seeps.

At the crook of the stairs where the water comes out, Obi-wan conobea (Leucospora multifida) has taken a spot. It's an annual forb that naturally occurs in seasonallly moist gravelly or sandy areas, areas with loose alluvium and a fair bit of moisture. It must be a prime spot for this species, since the plants seems to reliably return even after dying away from heat or frost.
https://www.inaturalist.org/observations/140991361

However, Obi-wan seems to be a bit of an explorer... as beyond those natural areas, he seems equally happy to thrive in more urban environments. Stairs and any sort of "step" area are a favorite.

In other words, anywhere there's a rocky "step" at a right angle—a flat step, and a vertical face, be it the next step, the curb or the wall—and sufficient moisture... General Conobea will be there. He also has been seen up in more ludicrous spots, e.g. up of the rooftop of Patterson Hall.

I would be remiss not to mention the origin of this plant's common name—if the reader is not already acquainted with the tale as viewable in the previous link. The plant was named by a well-known Chicago-area botanist, Floyd Swink, who evidently had a sense of humor:

The derivation of the strange common name comes from a publication of Floyd Swink, who named this plant after a character in the movie Star Wars, although the publisher did not discover this until after his book was already published (John White, personal communication). Another common name for this plant is Narrow-Leaved Paleseed, which was undoubtedly invented by a botanist. A scientific synonym for this species is Conobea multifida.
http://www.illinoiswildflowers.info/wetland/plants/conobea.htm

All that aside, natural seeps are interesting microhabitats to search for plants. Often, unusual finds—plants which thrive in higher moisture soils—will occur in seep areas, an island of moisture surrounded by otherwise dry and exposed uplands. An excellent example are the easternmost populations of Primula meadia, the Eastern Shooting Star, which grow in the Canyonlands east of the Balcones Escarpment. Something to keep in mind.

Posted on November 15, 2023 02:53 PM by arnanthescout arnanthescout | 1 comment | Leave a comment

July 10, 2023

Another typical backlog for the dedicated iNaturalist user...

I have so many photos in the backlog that I had to create a whole new photo album to keep track of them! These include photos from the field expedition to Panhandle Texas as part of my REU internship with the Morton Arboretum (note: that was an absolute blast). Our three-person team covered a lot of ground, from Monahans Sandhills State Park in West Texas to Quartz Mountain State Park in Oklahoma.

Of course, I will cull some of the not-so-good photos, since I tend to take more photos rather than fewer, but this is going to take hours for me to upload.

I'll get to them eventually, in the near or far future...

Also, I may have recorded a county record for Eryngium hookeri, at Matador Wildlife Management Area. I may upload that one sooner rather than later, with some encouragement. While I planned to collect a voucher for the population, research priorities and a surprise rainstorm distracted me from doing so. It is probably one of the furthest east records for that species, if confirmed. Thanks to Hunter Hopkins with TXPWD for showing us around!

Posted on July 10, 2023 04:03 AM by arnanthescout arnanthescout | 2 comments | Leave a comment

June 23, 2023

Scout no more?

I may no longer be a scout, or at least officially under Scouts BSA, for long. My scout troop may not recharter next year.

In the wake of the pandemic, a lot of the local scout troops and cub scout packs have suffered. The scandal and legal situation with the then-Boy Scouts of America organization (which they have rightfully owned up to) probably did not help. I've heard that several troops and packs have dissolved altogether. Overall, the past few years has been a rough decade for scouting.

My own troop was by no means large, but it was close and tight-knit, like a family. When I joined, there was just a little more than 10 members. We grew to nearly 30, before the pandemic hit. Now, they have become top-heavy with older scouts, and have been unable to recruit new members. Of the remaining active members, most if not all will either age out at 18 or reach Eagle (several completed their projects earlier this year). They've planned a final summer outing as their last big "hurray," to go out with a bang. I will be unable to join them as I am currently doing a full-time internship at the Morton Arboretum, but I joined in on several of my fellow scouts' Eagle Projects.

Scouting was a large part of my identity. I learned basic skills—camping, tying knots, how to start a fire. I took the Leave No Trace principles to heart, and continue my obligation to help other people at all times. Scouting helped me find my interest in plants (see "The Forester"). It was the same year I did my Eagle Project that my interest in the local flora really kicked off. I wanted to reinvigorate some of the skills I learned. I practiced my Basketry merit badge by weaving baskets from the twigs of a local willow. I discovered the joy of wild dewberries and foraging. I made cordage from the leaves of an agave plant in my backyard. Realizing that the plants were not just background, that put things into a new perspective. And of course, iNaturalist played a large part in helping identify the basic components of my local flora and connecting me with other naturalists.

As an Eagle Scout, I can honestly say that Scouting made me the person I am today. Part of that past is vanishing. And I am changing, my identity growing, beyond the labels I used to call myself. But I will continue to consider "Arnan the scout" a part of my identity, and the username will not change. Here's to memories of day's past, and to hopes of a bright future.

We all change, when you think about it, we're all different people; all through our lives, and that's okay, that's good, you've gotta keep moving, so long as you remember all the people that you used to be.

Arnan, Botanistrum

Posted on June 23, 2023 04:25 AM by arnanthescout arnanthescout | 1 observation | 0 comments | Leave a comment