Fascinating fungus | AspenTimes.com

Fascinating fungus

Anna Naeser
Aspen CO, Colorado

What you see in the picture is not what you get! I don’t have a photo to illustrate my topic because I was too slow. I did however get a photo that really shows off the daphne and anemone I talked about last week. Just before it rained, I got nervous enough to haul out the hoses and water most of the garden thoroughly. This happens to me so often, it’s almost enough to make me superstitious about what makes the rain fall.

Anyway, everything was nice and damp the morning after the long slow rain last week, and I did some easy weeding. I was working my way around the fruit trees and had just braved the dagger points of a large yucca to yank some filaments of cheat grass, when I backed into the scratchy Rocky Mountain juniper tree (Juniperus scopulorum). I was about to clamber around it, when I noticed it had orange spots in it and I got up to have a look. Clumps of some odd-shaped, slimy, yet rubbery matter decorated its leaves. Intrigued, I pulled one off and brought it indoors where I put it in a saucer of water to keep if from drying out until I could identify it.

I had once observed a bizarre orange growth flowing over the mulch in the border outside my office, in a kind of a living lava lamp effect. It was a slime mold. I wondered if I had some version of a slime mold on my juniper, so that’s where I began my research, but nothing turned up. I was stymied. While my daughter didn’t recognize it either, she pointed out that jelly-like orange blobs on saucers in kitchens might be mistaken for something to eat. Fortunately, no one had, since I had no idea if it was harmful, possibly even deadly, or a fabulous undiscovered food. However, I was taught from early childhood never to eat any bright unidentified things like berries or mushrooms. Maybe I had a fungus?

A few days later, I cracked open the latest issue of Discover magazine. Hah!! What did I see but a highly magnified picture of my orange thingy! It appears that my juniper tree is host to a disease called cedar rust caused by an indigenous North American fungus, a species of Gymnosporangium. The article by Gordon Grice in Discover titled “Pondering a Parasite”, was inspired by cedar-apple rust, which is well-known and documented because apple growers consider it a very serious disease, but there are many kinds. Gymnosporangium rusts alternate between members of the cypress family, mostly junipers, and members of the rose family, primarily apples, crabapples, hawthorns, serviceberries, and the like, in order to eat and reproduce. It’s a chicken and egg type deal ” which comes first? Spores are windblown or carried by insects from one host to the other. It takes one or two years for the complex life cycle to be completed. I never noticed the small galls that were formed when the fungus took up probably perennial residence on my Rocky Mountain juniper, sometime late summer or winter.

Only when conditions are exactly right, and only in spring, will the galls swell and effloresce, releasing masses of spores. Moisture is key. Gordon Grice vividly describes what happened on his juniper: “Through each spiky spout a vivid orange tentacle projected. It seemed as if the tree had collided with a swarm of sea anemones. I tried its texture myself: wet gummy worms.” My clumps looked more wedge-shaped than wormlike. It may be that I have a different species of rust, or that mine had begun to disintegrate, dry out, and die. I went out late in the day to photograph it and found not a trace. Apparently, the exotic process can be repeated for days in warm soggy weather, or be completed overnight.

Every time I notice something new in my garden, a whole new world opens up to me. Now that I know about Gymnosporangium rusts, I find myself checking every juniper I see for galls. Every wet spring I’ll be examining junipers with galls for signs of orange spore masses and I’m watching the apple, hawthorn and serviceberry leaves for the telltale colorful lesions that indicate some spores have found their way from their juniper hosts to their second home. If I am ever lucky enough to see this ephemeral gelatinous bloom again, you can be sure I’ll grab my camera immediately.