Tuesday, June 7, 2011

South Carolina Highlights, Part 2

Although Day 1 of our trip was excellent, Day 2 was even better. We only visited two sites on the second day of our excursion, but the first site that day was so interesting that it was the highlight of our trip for me. This site is known as Forty Acre Rock and Flat Creek Heritage Preserve, and it is considered by some to be the most diverse protected area in the piedmont province. We spent most of our time in the granite flatrock area of the site, pictured below.

In the photograph above, you can see numerous colors and textures indicative of a diverse array of plant species. In a few spots, including on the left side of the photo, you can see a bit of red coloration, which is a result of one of many dense colonies of Diamorpha smallii on the site. Elf Orpine, as it is known, has fleshy red leaves, a red stem, and pinkish-red fruit, and it grows in dense colonies. This tiny plant (only growing up to four inches tall) is only known from six states in the southeastern United States, where it grows in gravelly and sandy vernal pools in granite and sandstone outcrops and sandy flats.

The very similar Sedum pusillum, pictured below, also grows at this site, in populations that are geographically in close proximity to Diamorpha smallii but that are ecologically quite different. Whereas Diamorpha smallii grows in vernal pools, Sedum pusillum can be found in slightly drier parts of granite flatrocks under shade, often in association with Juniperus virginiana. Puck's Orpine, as this species is known, is only found in North Carolina, South Carolina, Alabama, and Georgia, and is a Federal Species of Concern. It flowers a bit earlier than Diamorpha smallii, and as a result many of the plants of this species that we saw had already matured to fruit.

In my previous post, I discussed Minuartia glabra. At Forty Acre Rock, the similar Minuartia uniflora was found on granite flatrocks. This tiny member of the family Caryophyllaceae, known as Piedmont Sandwort, is only known from North Carolina, South Carolina, Georgia and Alabama, where it grows in sandy or granite outcrops. As with nearly all of the other species growing on the outcrops at this site, Minuartia glabra is an annual.

Take a look at the shot below. What could Justin possibly be doing? Isn't he going to soil his Sunday best by tinkering on his tummy in that little puddle? Even if he did, it would be well worth it for the reward of the plant in the small vernal pool that is the object of his attention.

Probably the highlight plant of the trip for me was the tiny Pool Sprite that grows in these vernal pools at this preserve. Below is Amphianthus pusillus. It simply doesn't get much better than this, folks. The leaves of this plant are less than a half inch long, so you can get a feel for how small the flower is. This federally threatened species is endemic to the vernal pools in granite flatrocks in the piedmont of South Carolina, Georgia, and Alabama. Because these vernal pools are prone to rapid drying, this only member of the genus Amphianthus, an annual plant, conducts its entire life cycle in just three to four weeks. The other plant in the photograph below, by the way, is a quillwort, possibly (Isoetes melanospora).

After spending a good chunk of the day at this site, we drove to the coastal plain and botanized at Cartwheel Bay Heritage Preserve. Most of our time here was spent in the Longleaf Pine flatwoods, but we did venture into a couple of pocasins as well.

One of our highlights at this preserve was Carolina Ipecac, Euphorbia ipecacuanhae, shown below. This mat-forming euphorb is known primarily from the sandhills and coastal plain of several states along the east coast of the United States. The specific epithet gives you an idea of what would happen if you ate this plant... not only does it induce vomiting, but it also acts as a laxative. Don't try this at home... well, that may actually be the best place to try it, if you are so inclined.

Also at Cartwheel Bay, we saw the plant below.  We originally identified this as Iris tridentata, but thanks to the keen eye of one of our readers we've learned that this identification was incorrect. Instead, we now believe that this is likely Iris virginica.  However, there are two known varieties of this species present in South Carolina: I. virginica var. virginica and I. virginica var. shrevei.  The former is said to get up to 6 dm tall and to not be very branched, whereas the latter is said to get up to 1 m tall and to be more branched.  The plant that we saw with deep violet petals and sepals was at least 1m tall and was branched, indicating that it would be I. virginica var. shrevei.  However, that variety is not known from the coastal plain of South Carolina or from Horry County, where we found this specimen.

As it began to get dark, a Barred Owl called, signaling the end to day two of our short three day sprint through South Carolina. After such a great day two, what would day three bring?


Mike Whittemore said...

What a trip! After my internship in ND, I plan to hit a bunch of preserves on the way home. Looks like you planned yours out well!

Scott Namestnik said...

Hi Mike. Yes, we did some planning before our trip and had a good idea of sites we wanted to visit and some target species. It worked out well... we saw many of our target species and plant communities, though we missed a few as well.

Anonymous said...

That last photo is Iris virginica. I. tridentata has the (upper) petals dramatically reduced to about 1.5 cm long, mostly hidden by the bases of the sepals. Worth correcting since your photo is a top result in a Google search for tridentata.

Scott Namestnik said...

Good call, Anonymous... definitely not Iris tridentata now that I take a closer look and have your insight on the petal length. However, I'm still not convinced that it's Iris virginica. Are you familiar with Iris hexagona, and if so do you think this could be a possibility? Justin and I are very familiar with Iris virginica in the Great Lakes region, and this thing immediately struck us as something different.

Anonymous said...

Iris hexagona is reported from only four counties in SC, while virginica is widespread. See the South Carolina Plant Atlas for details. There's a few subtle things about your plant that look like virginica to me, but the most obvious is that hexagona usually has a large, leaflike spathe at the base of each flower. The only photo I've been able to find labelled as a South Carolina hexagona is here.

Scott Namestnik said...

Thanks again, Anonymous. Living in Indiana, I see Iris virginica var. shrevei frequently, but I don't know that I've ever seen Iris virginica var. virginica. The latter is said to be shorter (up to 6 dm tall) and little or not at all branched, whereas the former is taller (up to 1m) and usually with 1 or 2 branches. This plant was very large, at least 1m tall, and it was branched. If in fact it is I. virginica, it would have to be I. virginica var. shrevei, which is not known from coastal areas in South Carolina such as Horry County per Weakley's current distribution maps. Although neither Justin nor I thought that this plant looked at all like I. virginica var. shrevei, at this point that seems like the best option, and in that case it would represent a record outside of the known area for this variety.