Archive for February, 2020

Skunk cabbage flowers

February 5, 2020

The following photo gallery shows skunk cabbage (Symplocarpus foetidus) flowers in a forest seep located at an undisclosed location in Fairfax County, Virginia USA.

This is ideal habitat for Gray Petaltail dragonfly (Tachopteryx thoreyi) larvae, and in fact, numerous adult “Grays” have been observed along a sunny trail near this location. Seeps are home for some species of larvae from Family Cordulegastridae (Spiketails) as well.

03 FEB 2020 | Fairfax County, VA | skunk cabbage flowers

03 FEB 2020 | Fairfax County, VA | skunk cabbage flowers

03 FEB 2020 | Fairfax County, VA | skunk cabbage flowers

03 FEB 2020 | Fairfax County, VA | skunk cabbage flowers

The last photo shows the same location during early Summer 2019. The plant with broad green leaves is skunk cabbage.

01 JUN 2019 | Fairfax County, VA | forest seep, with skunk cabbage

The following quote is perhaps the best description of a forest seep that I’ve read.

[Some] small tributaries … have their sources in numerous woodland seeps. While a few of these perennial springs bubble up out of the ground, most arise in moist hillside patches with lots of decaying leaf litter and luxuriant stands of skunk cabbage. Source Credit: White, Harold B., III. Natural History of Delmarva Dragonflies and Damselflies (Cultural Studies of Delaware and the Eastern Shore) (Kindle Locations 1213-1215). University Press Copublishing Division. Kindle Edition.

Related Resource: Skunk Cabbage: First Flower of the Year… by Alonso Abugattas, Capital Naturalist blog. The blog post includes an embedded link to an informative video by Mr. Abugattas: Capital Naturalist: Skunk Cabbage Blooming (3:58).

Copyright © 2020 Walter Sanford. All rights reserved.

MYN – Tramea sp. exuvia (ventral)

February 3, 2020

An odonate exuvia, collected by Andy Davidson near Richmond, Virginia USA, was photographed against a pure white background using the “Meet Your Neighbours” (MYN) technique. Two photos were used to create a composite image: one photo focused on the prementum; and another photo focused on abdominal segment eight (S8).

This individual is from the Genus Tramea (Saddlebags), in the Family Libellulidae (Skimmers). Since it’s nearly impossible to differentiate exuviae from the Genus Tramea to the species level, we’ll leave its identity as Tramea sp. It’s the same specimen featured in my last three blog posts: MYN – Tramea sp. exuvia (face-head-dorsal)MYN – Tramea sp. exuvia (dorsal); MYN – Tramea sp. exuvia (dorsal-lateral).

Tech Tips

The subject was photographed against a pure white background using the “Meet Your Neighbours” (MYN) technique. The exuvia was “staged” on a clear plastic surface raised ~1.5 in (~3.81 cm) above the white background.

The dorsal side of the specimen was lying on the clear plastic. The “eyes” were closer to the light source than all other photos/composite images in a four-part series of this subject; as a result, the eyes look washed out. I know from experience that problem can be solved by moving the clear plastic stage farther from the white background.

In this case, I was less concerned about showing the eyes in their best light and more concerned about looking for signs of sex organs that indicate gender. I don’t see anything that looks like either vestigial genitalia (male) or a rudimentary ovipositor (female).

Copyright © 2020 Walter Sanford. All rights reserved.


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