Goldenrod

What’s still blooming: Chrysanthemums still have color from a distance, but up close many of the petals are stained brown.

Inside: African aptenia and asparagus fern.

What’s turned/turning red: Bradford pear, pasture rose, spirea, raspberry.

What’s turned/turning yellow: Most of the area yellow tree leaves turned brown; sour cherries, peach, rugosa rose, Apache plume, some iris leaves, Rumanian sage, catmint, yellow alyssum, Silver King artemisia.

Animal sightings: Mice have been trying to move into the house.

Weather: First snow landed on frozen rain on low leaves and stems in Monday morning dark; rain early Wednesday, then snow late; Tuesday morning in the high 20's, Thursday down to low 20's, and Friday.in mid 20's with raw wind; yesterday weather back to normal sunny 30 degree temperature swing; 10:01 hours of daylight today.

Weekly update: There are things I know, objectively, to be true, but have never experienced.

I know horseweed has tiny white flowers, although I’ve never seen one. I see buds and I see seed heads, but I never see the petals opened. The closest I’ve come was a dull day with clouds hiding a bright sun. In the special half light that extended into afternoon, I saw some flowers partly opened, almost daisies.

It’s often at such special times, like All Hallows’ eve, when conditions aren’t quite normal, that the usually invisible is revealed.

I know goldenrod is a member of the composite family, but all I’ve ever seen were yellow knobs on curving stems, usually from a distance. In Michigan in the 1970's, the rhizomes grew in large stands with white yarrow on land abandoned when I-94 was built in the early 1960's. This summer one large and at least three small patches rose from sides of irrigation ditches along the village periphery.

This year’s rain patterns were unusual. Showers continued into July, when it’s usually dry. Then, there was no rain in the usual monsoon season. There was more water than usual part of the summer, and little the other part. Few sunflowers or purple asters bloomed. We had no fall. It wasn’t their world.

My goldenrod, however, had larger flowers than usual and I could actually see the golden rays ringing flattened domes. Now the heads look like thistles. The white awns anchored to seeds are visible within the prongs of receptacle bracts that remain when the fluff has flown, like cotton bolls before the gin removes the debris.

Two weeks ago, the white balls reflected light. A week ago, after two days of rain and two days of cold, the pappus hairs that had once surrounded the florets were more dispirited, the browns more prominent. Yesterday, after more rain, more cold, and even some snow, the receptacles still clutched their remaining winged achenes.

One reason I could see my flowers so clearly this summer is they are stiff goldenrod plants I bought from Wisconsin’s Prairie Nursery in 2005. The major difference between Solidago rigida and the more common canadensis is that, while they have similar numbers of ray petals (6-13 versus 8-14), my species has 14 to 35 disc florets rather than the 3 to 6 found on the common perennial.

The sheer need for space for the disc flowers pushes the petals apart, making the center more visible. The fact the rigida disc corollas are also two to three times the size of canadensis only emphasizes the difference.

Some taxonomists have argued large flowers like mine aren’t really goldenrods and should be moved to another genus, tentatively called Oligoneuron. However, geneticists found rigida not only shares the same DNA with canadensis, but its subtribe appears to be an older, more basal member of the group.

Apparently, goldenrod began like any other composite, a daisy in a large cluster, somewhere east of the Mississippi. As conditions changed, the flowers shrank, but nature compensated by creating more to produce the same reproductive effort. However, rather than create great clusters like yarrow or horseweed to accommodate the increased number of florets, nature created the classic goldenrod form by extending the stem into a gooseneck and spreading the flowers along one edge.

Today, the USDA website has distribution maps for 75 Solidago species. Many are limited to the areas where they evolved. Of those that did spread, most live either east of the great plains, like stiff goldenrod, or in the west. Common goldenrod is the only one that has adapted almost everywhere. It can’t handle the humid southeast and, early in the twentieth century, Elmer Wooton and Paul Standley suggested in New Mexico, it only grew in Chama and on "moist ground in the upper Sonoran" that includes the Rio Grande valley.

This summer even the local goldenrod expanded with the unexpected early moisture. The peduncle stems, that hold individual flowers, grew longer, so the wands became airy plumes. Last weekend those canadensis heads, by then turned white, still maintained their form. But one, growing along a curve where its pappus of white fluff caught the morning light proudly proclaimed to any passing driver, "See I am a composite, see my glorious crown."

Notes:
Nesom, G. L. "Taxonomic Infrastructure of Solidago and Oligoneuron (Asteraceae: Astereae) and Observations on Their Phylogenetic Position," Phytologia 75:1-44:1993.

Semple, John C. and Rachel E. Cook Entries on Solidago, S. canadensis, and S. rigida at efloras Flora of North America website.

US Department of Agriculture plant profile for Solidago, available on-line.

Wooton, Elmer O. and Paul C. Standley. Flora of New Mexico, 1915, reprinted by J. Cramer, 1972.

Photograph: Stiff goldenrod seed head, 25 October 2009, winterfat in back.