The Iris and the Virus: The Wuhan Lab and My Garden

I went out into the garden early one Sunday a few weeks ago. A few, but not all, of many zinnias were covered with leaf spot and/or powdery mildew. Mosaic virus was disfiguring a handful of Cosmos sulphereus. Plants of our heirloom Mr. Stripey tomatoes, with withered foliage the color of a cigar wrapper, were dying a slow death.

Happy members of the Ramblers Garden Club holding my favorite passalong plant.

I’ll be frank. This may not be the Wuhan lab, but our garden is an incubator for some ugly pathology.

It’s that time of year.

Deluxe combination of powdery mildew AND leaf spot

The doctor is not answering calls. Walnuts are shedding leaves and dropping green- husked bombs, and I am losing steam. I should be begging for early frost to put our sick ward out of its misery, but autumn took a turn yesterday.

Temperatures cooled, and four enthusiastic members of Louisville’s Ramblers Garden Club came to Salvisa. A few months ago, the Ramblers asked me to speak to their club. I pleaded retirement. It’s more fun to have the willing come out to the country and enjoy a picnic, anyway.  

Zinnias none the worse for wear with leaf spot or powdery mildew

I offered a little show and tell

Despite immunocompromised  plants, virulent crabgrass and harlequin bugs eating the life out of our kale, there were a few plants to show off—from the simple to the esoteric.

I claim bragging rights for a gift of bug-eaten, one-of-a-kind variegated wood nettles from Julian Campbell, my talented botanist friend. Julian’s two-gallon pot had a bonus—native Miami mist (Phacelia purshii) seedlings. We’ve got a few patches growing at the edge of woods, but I can always use more.

The native annual Phacelia purshii

Despite unstable chimeral variegation, I’ve grown fond of this peculiar wood nettles, though no one has begged for a piece of the bug-eaten plant or been stung by its leaves.

No one yet is clamoring for a piece of Julian Campbell’s variegated wood nettles.

We’ve got a mother lode of common wood nettles (Laportea canadensis) along the Salt River. The three-foot tall carpet is as impenetrable as a mosh pit concert crowd at last weekend’s Louder than Life Festival in Louisville.

Daughter Molly, a talented gardener and forager, approves of our natural bounty. A few years ago, she made pesto with fresh leaves (wear thick gloves when foraging for wood nettles or stinging nettles [Urtica dioica], its kissing cousin). I have dried leaves for tea.

Wood nettles along the Salt River in Salvisa

And coincidentally, this summer, I noticed no invasive stilt grass growing where there are carpets of wood nettles. Julian Campbell thought this was interesting. I could find no evidence online of allelopathic root inhibitors, but the stoloniferous roots appear to shade out competition, except for a tangle of cat brier and poison ivy near the gravel road.

Looking for a tough perennial? Step right this way.

I sent each Rambler home with a roof iris. Iris tectorum is a drought resistant, no fuss, herbaceous perennial that forms thick weed-smothering clumps in full sun to partial shade with lustrous, medium-green, blemish-free, arching leaves and lavender-blue blooms.

Frank Bell’s gift of roof iris

The unblemished foliage of Iris tectorum in late September

My plant came from Frank Bell who collected this in Wolong, Sichuan Province, not far from the Panda Breeding Centre, in 1996, with Dan Hinkley and Darrell Probst.

Here’s the rub.

Besides Sichuan, Iris tectorum also grows in Hubei Province.

Should this be cause for concern?

The iris and the virus.

As the crow flies, Wolong and the Wuhan Lab, are less than 700 miles from one another.

And though the roof iris grows in Hubei, I am not certain if it grows in Wuhan, the province’s capital city.

Just to be safe, I plan to get a Covid booster later this week.

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I asked Frank Bell, plantsman and retired lawyer, from Lexington, North Carolina, what he remembered from two collecting trips, especially around Wolong , where he collected Iris tectorum. He relied on collection notes and memory. “I will never forget roaming those spectacular river gorges.”

Wolong Reserve is centered on the Shaotang River valley, and the main road follows this river. Two tributary rivers flow into the Shaotang from the north, the Pitiao river and the Yinchang river. 

The Pitiao confluence is just east or downriver of the Panda Station, and the Yingchang confluence is further up the Shaotang valley, west of the Panda station. From the confluence at 2000 meters, the Pitiao gorge cuts through the heart of the reserve and its surrounding ridges exceed 5000 meters. Its headwaters rise off  Mt. Balang on the eastern edge of the Tibetan plateau .We had our driver leave us where the road turned away at the confluence. A dirt track along the Pitiao led to a stone hut and then to an old concrete bldg. upstream beside a small dam on the river. It was for local power generation and not impoundment. A track continued beyond the dam where the gorge narrowed. The riverbanks consisted of small boulders fully vegetated with bamboos, ferns, herbaceous plants, shrubs and rhododendrons. The track turned up from the river and cut into the rock cliffs hanging over the river along a narrow rock ledge 20-30 meters above the river. Epimedium davidii covered the cliffside and caught the attention of Dan.  What was left of the path was slippery, covered with loose rocks and exposed to the river below.  I continued alone upriver and eventually the way opened some. I found the iris up there among the rocks along the river . The gorge there was very narrow with high ridges on both sides. Further on, the way disintegrated into a rhododendron hell. I backtracked and caught up with Dan Hinkley & Darrell Probst near the confluence.

In Oct. 1998, Dan and I asked to be dropped off at the Yingchang confluence. It is a wider valley than the Pitiao and had a good trail maintained by the locals, who called it Sleeping Dragon Valley. We spent a half day up there botanizing and collecting. We found the iris up there in similar conditions as along the Pitiao and I made another collection there. I’m not sure which collection I gave you.

The Yingchang valley sat directly on the fault line of the catastrophic 2008 Wenchuan Earthquake (69,000 dead). In the Yingchang the mountains collapsed into each other, entirely burying the local villages and the Sleeping Dragon valley. That part of Wolong Reserve remains closed to tourism.

Dan Hinkley wrote about collecting in these gorges in his The Explorer’s Garden books: Shrubs and Vines; and Rare and Unusual Plants.