Mac Is Back!

Day 258: Mac is back! Last year, my "pet" Corallorhiza maculata was nipped off by something (deer, slug, squirrel...I don't know who the culprit was) when it was only about six inches tall. This year, she's making up for lost time by putting up two stalks which, as you can see here, are just beginning to flower. I've done my best to protect the plant by installing an 18" high chicken-wire fence around it, staked to the ground with short lengths of bamboo garden wand. That said, the Corallorhizas are amazingly resilient. Many can remain in a dormant state for years without ever breaking ground. The key lies in the plants' companion fungi. Each species of Coralroot has one or more specific "companion" fungi on which they depend. The fungi break down nutrients in the soil which can then be taken up by the plant. Currently, there is debate among botanists as to whether this is parasitism (in which case the fungus derives no benefit from the plant) or true mycoheterotrophy (a cooperative arrangement in which plant and fungus provide some requirement). I hold with the latter view on the hypothesis that if a long-term partnership has evolved, then it must in some way be advantageous to both parties. Despite the fact that we haven't identified what that exchange might be, absence of evidence does not negate the possiblility of it existing in some way we cannot detect. Good science is inquiry, not denial.

Mac Is Back!

Day 200: I've been checking every few days for the last two weeks. Mac is back! My "pet" Corallorhiza maculata in the back yard is all of an inch tall. So far, only one stem has poked through the ground, but I'm hoping for more with good reason: I believe I may have identified this particular plant's mycorrhizal associate. C. maculata is a mycoheterotroph, and as such is a bit less discriminating than some of the rarer species. It associates with a wider range of fungi, as opposed to C. trifida or C. striata which are more specific in their partnerships. My Mac may be working in tandem with Ramaria acrisiccescens, a common coral fungus which goes by the unlovely common name of "Blah Coral." Last fall, several lines of R. acrisiccescens fruited in her immediate vicinity along the shadowy edge of my wooded strip. Given the abundance of the fungus, Mac may be able to start a family of her own.

Mac

Day 255: Lovingly nicknamed Mac, my "pet" Corallorhiza maculata is now just past her prime. She reached a substantial height of 20" and bore at least two dozen individual flowers.

Although the Corallorhizas form seed ("dust seed," extremely fine), they cannot germinate without the aid of soil mycorrhizae. The exact process is not well-understood. Some research has indicated that the mycorrhiza aids in breaking down the sheath surrounding the seed. What we do know is that the mycorrhiza is responsible for breaking down nutrients in the soil, converting them to a form which can be used by the plant. Interestingly, each species/subspecies of Corallorhiza is affiliated with a different fungal partner. Apparently my back yard suited Mac's needs. In the thirty years I have lived here, I have not found Corallorhiza on the property, but another thing we know about these marvelous mycoheterotrophic species is that they can disappear and lay dormant for more than 25 years, emerging again only when conditions are ideal. Given our relatively mild, wet winter, I had predicted that this year would be a boom year for mycoheterotrophs. My projection is being borne out not only near my home, but as friends and colleagues report in, the abundance is being noted throughout the Pacific Northwest. Due to COVID-19, I'm forced to enjoy most of them vicariously, but every day, rain or shine, I step out into my yard for a few minutes to tell Mac how beautiful she is.