Sunday, June 4, 2017

Milkweeds of the Coosa Valley Prairies

Whorled milkweed (Asclepias verticillata)
The Coosa Valley Prairies in Floyd County, GA have small patches of tallgrass prairies with species that are unique. Yesterday I participated in a Georgia Botanical Society field trip there and we explored some of the 929 acres that The Nature Conservancy has under conservation easement. I’ll cover the trip in more detail in the next blog, but one of the interesting aspects was the assortment of milkweeds found there – 6 species were observed!

Many of us have seen the bright orange milkweed (Asclepias tuberosa) on the side of the road so we know milkweeds in general can handle tough, dry conditions. This area was an amazing display of 5 species thriving in the prairie: butterfly milkweed (A. tuberosa), prairie milkweed (A. hirtella), greenhorn milkweed (A. viridis), short green milkweed (A. viridiflora), and whorled milkweed (A. verticillata). We also found white milkweed (A. variegata) in the some of the surrounding woodlands.

The first one we found was the short green milkweed (Asclepias viridiflora), also called green comet milkweed. Although it is very non-descript, the flowers petals and sepals remain tightly reflexed, it still serves an important ecological purpose and we were delighted to find a caterpillar on one of the plants. After I got home, I identified it as an ‘unexpected cycnia,’ a small moth (Cycnia collaris).

Asclepias viridiflora
A. viridiflora with Cycnia collaris

Next we found the prairie milkweed (Asclepias hirtella). It has flowers clustered along the stems and long, thin leaves. The flowers are so numerous that they create a ball-shaped inflorescence. We continued to find it throughout the day, including one plant with a monarch caterpillar feeding on it. This species is only found in a few locations in Georgia, so it was exciting to be able to see it.

Prairie milkweed (Asclepias hirtella)

Aslcepias hirtella, the long view

Asclepias tuberosa 
Butterfly milkweed (Asclepias tuberosa) was in abundance throughout the site (as well as on roadsides in Floyd County). As one of my favorite native plants, it is always a pleasure to see it and to observe the many different shades of orange that it has. This area has some especially deep orange flowers.

Asclepias verticillata

The fourth milkweed we found was one of my favorites for the day: whorled milkweed (Asclepias verticillata). The plant is small and slender with tiny leaves and flowers; it seems easy to overlook, but it is found throughout Georgia. The flower clusters are also along the stem like prairie milkweed, but the number of flowers in each cluster is much smaller. The pink buds opening up to creamy flowers is a very beautiful effect.

Greenhorn milkweed (Asclepias viridis)

It seemed we might be too late to see the greenhorn milkweed (Asclepias viridis) in flower because the first plant we found had two huge seedpods on it. Reported populations in Georgia are few and far between so I was anxious to see this large-flowered species. We finally did find one that was still flowering. It is a short, stocky plant with long, broad leaves and large flowers. It was an exciting find, and everyone gathered around for pictures of this single plant in flower.

The sixth and last milkweed that we found was long past flowering and not in the prairie. White milkweed (Asclepias variegata) enjoys shadier conditions than the prairie so it was in the rich woodland that we walked through to get from one area to another. All in all, a spectacular day for not just seeing milkweeds but unusual ones!

1 comment:

  1. Wow! That is an impressive collection of milkweeds in one area. How cool to find the Cycnia collaris moth cat!