Gumweed

What’s blooming in the area behind the walls and fences: Hybrid tea roses, bird of paradise, buddleia, silver lace vine, honeysuckle, trumpet creeper, Heavenly Blue morning glories, purple phlox, Sensation cosmos, French marigolds, cultivated and farmer’s sunflowers; pyracantha berries; local supermarket roasting green chile people buy by the burlap bag.

Outside the fences: Tamarix, Apache plume, whorled milkweed, leather-leaf globemallow, velvetweed, scarlet beeblossom, white and yellow evening primroses, bindweed, datura, scarlet creeper, pale trumpets, clammy weed, stickleaf, Dutch, white prairie, and white sweet clovers, buffalo gourd, goat’s head, alfilerillo, prostrate knotweed, toothed spurge, pigweed, ragweed, Russian thistle, chamisa, snakeweed, goat’s beard, paper flower, spiny lettuce, horseweed, strap-leaf and golden hairy asters, áñil del muerto, native sunflowers, goldenrod, gumweed, Tahokia daisy, late summer grasses; buds on broom senecio, heath and purple asters.

In my yard looking north: Miniature roses, golden spur columbine, Hartweig evening primrose, nasturtium, chocolate flower, blanket flower, coreopsis, Mexican hat, black-eyed Susan, anthemis, yellow cosmos, chrysanthemum.

Looking east: Floribunda roses, hosta, hollyhock, winecup, sidalcea, Jupiter’s beard, large-leaf soapwort, baby’s breath, pink evening primrose, Shirley poppy, reseeded and Crimson Glory morning glories, garlic chives, Autumn Joy sedum, cut-leaf coneflower, zinnias, Maximilian sunflower.

Looking south: Blaze and rugosa roses, rose of Sharon, Illinois bundle flower, sweet pea, tomatillo.

Looking west: Russian sage, caryopteris, catmint, lady bells, David phlox, flowering spurge, blue flax, perennial four o’clock, calamintha, lead plant, purple ice flower, purple coneflower, Mönch aster; purple coneflowers germinating.

Bedding plants: Moss rose, snapdragon, nicotiana, sweet alyssum; Sweet 100 tomatoes reddening.

Inside: Aptenia, asparagus fern, zonal geranium.

Animal sightings: Rabbit, hummingbirds, gecko, cabbage butterfly, bee, black harvester and small red ants, mosquito.

Weather: Storm came through Monday; left little water but temperatures began dropping ten degrees some mornings; rain yesterday, heavy mist this morning; 13:04 hours of daylight today.

Weekly update: I live on a hill. The road descending the slope makes a ninety degree turn outside my drive. The opposite lot is vacant and monsoon weeds grow to the pavement edge, further limiting visibility.

Since it’s a county, not state road, there’s no maintenance. Neighbors with mowers and blades rake the shoulder whenever they get annoyed. The taller, late-growing plants come back, while shorter ones like hairy yellow asters and toothed spurge thrive at their bases.

For years, Russian thistle and pigweed were the primary plants. Last summer, white sweet clover was dominant with some gumweed and Hopi tea joining the mowed asters.

These apparently were considered worse than the allergens. Last winter, someone used his snowplow to scrape back several feet into a short berm. For the next several weeks, the edge of the road was impossible to find because loosened dirt washed across the pavement.

Ragweed came back in place of the clover. Since it remained short until the past week, the gumweed wasn’t cut down in July and has grown knee to thigh high. While the bushy mounds are covered with buds, few are ever open. They blend into the mass of noxious greenery along the curve.

Gumweeds are survivors. The most common form, Grindelia squarrosa, emerged in the Great Plains, possibly within the Rocky Mountains, but has been reported everywhere in the country except the southeast. It’s a typical late summer composite, yellow with disk and ray flowers, a deep taproot, and seeping resin that coats the thick leaves.

As it moved southeast into Kansas and Texas, curly gumweed shed it’s ray flowers and developed reddish stems. Many think that it became a separate species, Grindelia nuda. Other gumweed species are found only in Texas, suggesting the effects of isolation on a plant adapting to changing soils and irrigation patterns.

The gumweed growing by my drive is likely to have twice the chromosomes as other gumweeds, but most consider aphanactis to be a subspecies of nuda. In western Chihuahua the teeth along the leave edges of aphanactis are more spiny than glandular. West of continental divide, nuda crossbreeds with endemic Arizona species in still more attempts to adapt to even harsher environments.

The local gumweed, when given the opportunity, begins branching a foot or so above ground and rebranches into separated terminal buds. The outer shell of each is covered with rows of flexed leaves or bracts that make the rounded buds look more formidable than they are.

As it opens, the young head widens out into a concave disk that often fills with the gleaming white resin. The collection of narrow, tubular flowers continues to expand into a flat button surrounded by bracts. Finally, the outermost ring of disk flowers grows taller.

Lenora Curtin thought the fringe collected pollen from the center, when the flower failed to be pollinated externally. However, Max Dunford, who experimented with crossing aphanactis with local Texas and Arizona species, believes the flowers cannot fertilize themselves.

One would think the highly visible gum would have invited experimentation, but the Navajo have more recorded uses for the liquid than the Pueblos. They used it to induce vomiting, destroy ant hills, and bind cuts. It may be the plant was replaced by other cures after the conquest, since William Dunmire and Gail Tierney have heard Picuris and San Juan used it for kidney problems, Jemez used it to clean skin abrasions, and Cochiti used the flowers to relieve toothache pains.

However, Curtin found northern New Mexican Spanish speakers had found more uses for yerba del buey, than the indigenous people in the 1940's, including a tea for kidney problems and steam for rheumatism. Even today, Robert Trotter found aphanactis is one of the home remedies used along the lower Rio Grand in Texas to treat sores, while Michael Moore has discovered other local uses that exploit the anti-bacterial qualities of the leaves.

An alternative explanation for the comparative paucity of pueblo uses is that the plant was simply less common in the past when the native herbals were being developed, but was more common by the time the Navajo and Spanish invaded. We know it was in the area in prehistoric times from a bowl, containing edible amaranth seeds mixed with gumweed seeds. No one knows if the mixture was deliberate, or simple contamination from two plants in seed at the same time.

We also know gumweed thrives on overgrazed and otherwise destroyed lands and that it, and the allied squarrosa, spread along rail lines and roads. When Meriwether Lewis first spotted squarrosa, it was growing along the Missouri. When Joseph Hooker saw aphanactis in 1887, it was growing in Cañon City, a mine support town on the Arkansas. When Per Axel Rydberg documented the rayless flower in 1906, he found the biennial on the sandy soils around the rail town of Durango in southwestern Colorado.

Sometime last Sunday, after I’d taken my pictures, someone cut a foot wide swatch of verbiage around the curve, including the ragweed and gumweed, to leave the dying plants to mulch their seeds. Once again, someone has insured the ruderal plants will continue to thrive when already degraded land is newly abused.

Notes:
Curtin, Leonora Scott Muse. Healing Herbs of the Upper Rio Grande, 1947, republished 1997, with revisions by Michael Moore.

Didry, N., M. Pinkas, and M. Torck. "The Chemical Composition and Antibacterial Activity of Leaves of Various Grindelia Species," Plantes Medicinales et Phytotherapie 16:7-15:1982.

Dunford, M. P. "A Cytogenetic Analysis of Certain Polyploids in Grindelia (Compositae)," American Journal of Botany 51: 41–61:1964, cited by Strother and Wetter.

Dunmire, William M. and Gail D. Tierney. Wild Plants of the Pueblo Province, 1995.

Moore, Michael. Los Remedios, 1990.

Nesom, G. L. "Studies in the Systematics of Mexican and Texan Grindelia (Asteraceae: Astereae)," Phytologia 68:303-332:1990; considers aphanactis part of nuda.
Moerman, Dan. Native American Ethnobotany, 1998, summarizes data from a number of ethnographies including Paul A. Vestal, "The Ethnobotany of the Ramah Navaho," Peabody Museum of American Archaeology and Ethnology Papers 40:1-94:1952.

Rydberg, Per Axel. Flora of Colorado, 1906.

Strother, John L. and Mark A. Wetter. "Grindelia squarrosa (Pursh) Dunal," on eFloras’ Flora of North America website; considers aphanactis part of squarrosa.

Trotter, Robert T. II. "Folk Remedies as Indicators of Common Illnesses: Examples from the United States-Mexico Border," Journal of Ethnopharmacology 4:207-221:1981.

Weber, William A. "Colorado Collections Made by Sir Joseph Hooker in 1887," Journal of Biogeography 30:679-685:2003.

Photograph: Aphanactis gumweed in most of its phases, 22 August 2010, with hairy yellow asters in back; the reflections are from the resin.