A threatened Hexastylis (Heartleaf) species in Spartanburg County, South Carolina — 2016-04-28

The past few days were very busy for me with trips to South Carolina, North Carolina, and Tennessee, therefore I’ll break these multiple field trips into two sections: this one covering a very rare Hexastylis species and another covering a newly named Trillium species from Tennessee and a wide variety of colorful Trillium species from the Blue Ridge Parkway in North Carolina.

On Friday, April 28, I visited a Heritage Preserve in Spartanburg County, South Carolina to locate the rare, federally listed as threatened, Hexastylis naniflora or Dwarf-flower Heartleaf. I made the trip because I had a couple of friends from Atlanta, Georgia (Alan Cressler and Steve Bowling) coming over to see and photograph this unusual plant. I wanted to make sure it was in flower before we took time to drive over to Spartanburg to photograph it. It occurs in only 9 counties in the Piedmont of North Carolina and 2 counties in Piedmont of South Carolina. Many of the populations are very small with only a handful of plants, however, the site we would be visiting is considered to be the second largest site with thousands of plants (plant survey count in 2012). Here are images of the flowers and leaves:

Dwarf-flower Heartleaf flowers and leaves

There are at least 10 Hexastylis species in the Carolinas, and this one is the rarest, although it can be locally abundant in a few of its locations. As the common name indicates, the flowers are relatively small compared to some of the other species whose flowers approach 1.5 inches (3.75 cm) wide. The flowers of Hexastylis naniflora are slightly smaller than a penny (U.S. 1-cent coin), which is 3/4 inch (~19mm) wide. Here is a shot showing the flowers with a penny used for scale:

Here is a closer look at the nine flowers from the plant in the first image:

It’s rather puzzling why I have not photographed these flowers before now, since my home is only 45 minutes away. Alan had been asking about this species, so I was motivated to ask around to find out exactly where they grow. The Heritage Preserve for these plants contains a creek which meanders through a hilly woodland of mostly deciduous trees with a few pines scattered here and there. The plants seem to prefer moist, north-facing slopes bordering the flood plain of the creek.

There is a wide variety of color found in the flowers from deep purple to yellow/tan to yellow with green overtones. All of the flowers are covered with purple hairs. Here are some shots showing this color range:

The flowers are rather strange in that they bloom at ground level. I understand that they are pollinated by ants or beetles, so their being close to the ground seems to be a well-thought-out plan. In fact, only rarely does one see the flowers without brushing away the leaf litter from the base of the plants. They are also unusual in their shape — like a horizontally placed urn. Here is a profile shot of one of the flowers:

More images of Dwarf-flowered Heartleaf flowers:

This was a portentous beginning to what turned out to be a couple of days filled with interesting native wildflowers. Alan and Steve and I love being out in the wild searching out unusual and beautiful wildflower species, especially in the Carolinas and Georgia. As I mentioned at the beginning of this post, the remainder of our weekend field trips to North Carolina and Tennessee will be the subject of my next, rather lengthy blog post. Stay tuned…

–Jim