Observations by cotinis

Water Striders - Gerridae (2-4 mm)
Also posted at:
bugguide.net/node/view/2348853
Perhaps Metrobates species:
bugguide.net/node/view/649380
or
Trepobates species
https://bugguide.net/node/view/71333

Updated caption:
Elada Checkerspot - Texola elada (syn. Microtia elada; male, female)
References

• Brock and Kaufman, Butterflies of North America (Houghton Mifflin, 2003), pp. 180-181
• BugGuide bugguide.net/node/view/466183

See comments below. Thanks for the ID correction.

Carolina Anole - Anolis carolinensis (male)
Apparently, in this species only males have a colorful dewlap, but in some Caribbean species the female has a prominent dewlap as well (Internet searches and various printed references).
You can see the support bone(s) of the dewlap here because of the backlighting.
"The dewlap is erected by the movement of the hyoid apparatus, a set of bones derived from the gill support of fish and functioning in tongue support for most land vertebrates, including humans."
lucec.loyno.edu/natural-history-writings/anoles-and-dewlaps

Carolina Anole - Anolis carolinensis (male)
Apparently, in this species only males have a colorful dewlap, but in some Caribbean species the female has a prominent dewlap as well (Internet searches and various printed references).

Great-tailed grackle - Quiscalus mexicanus (male and female)
Sequence shows courtship behavior. A male was pacing about on a lawn. A female came near and he went into a frenzy of displays and calls. I think they did mate, but it was such a brief flurry of activity, it was hard to tell.

North American Porcupine - Erethizon dorsatum
Neighbors at the resort alerted us to an adorable porcupine snoozing behind their cabin. They said it had been there a couple of days, but it was not seen on 8 April and subsequently. It dozed while I took photos, appearing rather bored. This was only the second time I've seen this species.

This substantial snake was struggling to swallow a large fish. I think it is a...
Diamondback Watersnake - Nerodia rhombifer
This seems to be the species reported from the park.
Nerodia sipedon does not occur this far west, I believe. I guess N. erythrogaster also occurs in Texas. I don't think this is that species.
Opinions welcome!

Two-lined Leather-wing, Two-lined Cantharid - Atalantycha bilineata (syn. Ancistronycha bilineata, length 7.5 mm)
Also posted at:
bugguide.net/node/view/3274
References

• BugGuide bugguide.net/node/view/3114
• Dillon and Dillon, A Manual of Common Beetles of Eastern North America (Row, Peterson, and Company, 1961), p. 264, plate 26(12)

Photo taken with an early generation digital SLR, the Canon 10D (6MP sensor). If I was careful not to push the ISO, images from this camera were just fine! That Tamron macro lens was excellent--I only traded it in for a Canon later because it tended to get grit caught in the barrel as it extended. I believe this to be the first image of a living specimen of this species, at least the first one that was widely accessible. I identified it based on Dillon and Dillon's guide.

Clubtail - Phanogomphus species (male)
Also uploaded at:
bugguide.net/node/view/2341848
Update to caption based on ID here on iNaturalist:
Ashy Clubtail - Phanogomphus lividus (male)
References

• BugGuide https://bugguide.net/node/view/17841
• Beaton, Dragonflies and Damselflies of Georgia and the Southeast (University of Georgia Press, 2007) pp. 190-191
• Dunkle, Dragonflies Through Binoculars: A Field Guide to Dragonflies of North America (Oxford Press, 2000) p. 69, plate 8
• Paulson, Dragonflies and damselflies of the East (Princeton University Press, 2012) pp. 230-231, figs. 136.1, 136.2

Southern Dwarf Blueberry, Small Cluster Blueberry - Vaccinium tenellum Aiton (syn. Cyanococcus tenellus)
A rather obscure blueberry, grows in rhizomatous clumps and is only 10-40 cm tall. Mostly restricted to xeric woodlands of the Coastal Plain of the Carolinas. Second/third images here shows another stem nearby.
Just a few were blooming on 21 March 2024. I had seen them in full bloom 6 April 2023:
www.inaturalist.org/observations/154083884
References

• Carolina Nature (Will Cook): www.carolinanature.com/trees/vate.html
• Porcher and Rayner (Univ. of South Carolina Press, 2001), A Guide to the Wildflowers of South Carolina, p. 245 (photo)
• Radford et al., Vascular Flora of the Carolinas (UNC Press, 1968), pp. 814 (key), 815 (description)
• Weakley, Flora of the Southeastern United States (UNC Herbarium, 2020), pp. 1183, 1187

Sandhills Heartleaf - Asarum (Hexastylis) sorriei)
Hard to see the pattern on the leaf for all the pine pollen!
For references, see observation of this same species, I think, at the same site.
www.inaturalist.org/observations/111488120

Dimpled Trout Lily - Erythronium umbilicatum Parks and Hardin
This is the common lower Piedmont species. Erythronium americanum is also present at this site, but less common, and mostly(?) blooms later, I think. Extracting a bit of Weakley's key, the two can be differentiated:

• Petals (inner tepals) lacking auricles at base; capsule and ovary distinctly indented (umbilicate) at apex-->E. umbilicatum
• Petals (inner tepals) with auricles at base; capsule and ovary truncate, rounded, apiculate, or beaked at apex --> E. americanum

References

• Porcher and Rayner, A Guide to the Wildflowers of South Carolina, (Univ. of South Carolina Press, 2001) p. 175
• Weakley, Flora of the Southeastern United States (UNC Herbarium, 2020), pp. 220-221

Update to caption:
Cut-leaved Toothwort - Cardamine concatenata
NOT Slender Toothwort - Cardamine angustata.
With pollinating bee, Andrena species (adjacent observation).
https://www.inaturalist.org/observations/203852156

Putty Root - Aplectrum hyemale
Foliage present mostly in winter and early spring, like the much more common Cranefly Orchid, Tipularia discolor. I cannot recall seeing so many Aplectrum in a clump like this previously.

Maculated Scarab, Gnorimella maculosa, Durham County, NC. This beetle flew onto a Box Elder tree adjacent to a line of ants while I was standing in a parking lot, talking to a friend. I had time for just two shots before it flew off. This beetle is rather uncommonly photographed--a beetle expert friend (@sc_beetles) says he has never seen a published photo of a living specimen, see posting from 21 April, 2005:
bugguide.net/node/view/15371/
Comment on that posting:
"A first?
I have never seen a photo of this species in the wild - very good.
… Phillip Harpootlian, 22 April, 2005 - 6:48am"

Other BugGuide photos of living individuals date from 2008.
There is a photo of this species in Stephen Marshall's Book, Insects--their Natural History and Diversity (2006).
Though I do not know when that 2006 photo was taken, this would appear to be the first photo of a living individual published (online or otherwise)
I have not seen it again as of March 2024.