Gum plant or gum weed, your call
Patches of these bright yellow daisy-like flowers grow along the shore west of the paved perimeter pathway on the west side of the park in the spring. They hug the ground and don’t mind the wind and the occasional salt spray. They’re Grindelia stricta, probably of the platyphylla variety, also known as gum weed, gum plant, Oregon gum, and other names. It’s hard to pin down the exact variety because different varieties exchange genes in the wild and hybridize. The “gum” in the name comes from a sticky white resin that the bud exudes before it opens up. You can see little streaks of the white gum in the bud to the left of the open flower in my picture. The resin is yucky to predators. The plant is native to California coasts, in fact, to the coast all the way up to Alaska. It also finds use as a cultivated ground cover in coastal gardens, where of course it gets promoted from gumweed to gumplant. There are bee populations that specialize in pollinating only Grindelia stricta.
Intrigued by the gummy resin I searched Google Scholar, and learned that the plant is a source of grindelic acid, which is a terpene, and has more than 20 closely related compounds. However, this acid is derived from the whole plant, not specifically from the resin. You can buy 1 milligram of grindelic acid on the commercial chemical market for $192.50. I did not come away any wiser than that, but did learn along the way that the plant got its Latin name in 1807 from Professor Willdenow of the Berlin Botanical Garden who received seeds from Professor Broussonet of Montpellier in 1806, who got them from one M. Sessé who brought them to Madrid from Mexico in 1805. Willdenow named them after Professor Grindel of Dorpat. If anyone has seen anything of interest about the gummy resin please post a comment. Thank you.
I wanted to know why they just showed up in my field one year when we’d never noticed them before. I was told the gun weed likes a lack of inactivity and a dry climate . That made sense . Up to the time we’d noticed the weed the field had been mowed weekly. The field was left for about a year without any mowing and thru a hot season and up popped these nasty sticky flowers. I want some information on how I can best get rid of them. They clog up a mower so badly you need a pressure washer to clean the gun off after each use and even then it’s a real chore. Aside from just back to mowing regularly what can I do to discourage them from growing? I want them GONE.
Looking for some information on what to do..
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