Friday, September 16, 2011

Mystery Solved (?)

Now and again on my travels I chance upon odd things that are baffling, such as this photo taken back in mid-June. What is this strange and weird orange nodule? A gall? A fungus? A cluster of insect eggs?

As often happens random chance played a role in the solution. I was Googling for information on nettles when I stumbled upon images of a nettle gall, Puccinia urticata ... not quite like my unknown blob, but pretty close. A bit more searching turned up a better possibility – Cluster Cup Rust Fungus (Puccinia caricina). These fungi have a complex life cycle that alternates between more than one host plant; this is the aecia or spore producing structure of the fungus.

But my mystery isn't quite solved: Puccinia caricina alternates between sedges of the genus Carex and species of Ribes, forming the "cluster cups" containing aeciospores on gooseberries and currants. My fungus was on dogwood, and as yet I haven't found rust fungi utilizing dogwood as host plants. But I'm sure the answer will turn up eventually, as there are more than 4000 species of rust fungi to choose from ...

This photo taken in early August also rates among my most unusual finds for this summer. Obviously these little things had been moving and consuming the surface of the oak leaf. What are they? A species of slime mold? Slugs? Insect larvae? Try searching the Internet; if you're stumped the answer may be found in The Forest Floor Fungi at the Frink Center.

Based on size, general appearance and range, I think this spider is a Humpbacked Orbweaver (Eustala anastera); there's more information on genus Eustala at BugGuide.Net. And what a well concealed spider this is. It looks almost like a part of the knot it's hunkered down in, and had I not almost blundered headlong into its web and traced the strands back to their origins, I would have passed it by.

But this arachnid comes in a wide assortment of colors and patterns and it seems that I have not a mystery, but a mis-identification. While browsing the Eustala images at BugGuide.Net the photo to the far right in the second row caught my eye – this spider bears more than a passing resemblance to the "Giant Lichen Orbweaver" photos I posted last year in What's for Lunch?.

The plant in the next photo was encountered growing in the woods bordering Rapids Road late in August. The distinctive triple-compound leaves and spherical blue fruits should have made it a cinch to identify, nevertheless it took some time to find a name (it's not easy to search for images using a text description).

This is a species of Blue Cohosh – but all I can say based on the information in the photo is that it belongs to the genus Caulophyllum. There are two species of Caulophyllum in southern Ontario, the Purple-flowered Blue Cohosh (Caulophyllum giganteum) and Green-flowered Blue Cohosh (Caulophyllum thalictroides), and it looks like I'll have to wait until this plant blooms next spring to find out which one it is ...

The following photos have been sitting in my "unidentified" folder since I first encountered this flower a couple of months ago along the Moira River shoreline. Actually a close relative of Common Yarrow, the flowers of Sneezewort (Achillea ptarmica) resemble the flowers of Pearly Everlasting, and due to this superficial similarity I went on a proverbial wild (and unsuccessful) goose chase when trying to identify this plant.

The leaves have finely serrated edges.

This is a good example of why it's helpful to understand a bit about the structure of flowers. What appear to be the ray florets of Pearly Everlasting are actually phyllaries, the ray florets of Sneezewort really are ray florets. The next picture, taken a few weeks later, illustrates the phyllaries of Sneezewort ... with some complimentary caterpillar poop ... it appears that some species of insect finds this plant to its taste.