Banner Blooms
Flowering monument plants proliferate across Colorado

A field of green gentians, aka monument plants, catch the early morning sun north of Coal Bank Pass on Monday. For some inexplicable reason, the plants, which can grow as old as 80 years, bloom once and then die, are blooming profusely across the state./Photo by Todd Newcomer.

It’s truly a phenomenon. I tell this to the new batch of apprentices who have signed on to learn about herbalism this summer. My boss, flitting around the Rockies for two weeks, has left me in charge of the knowledge-hungry girls who are promised a weekly class in exchange for the hard work they give to the herb shop.
“ I’ve lived here for nine summers and haven’t ever seen this before.”

I am referring to the prolific green gentian bloom, the flush of cream-colored wands rising out of mountain slopes across Colorado in the tens of thousands. Green gentian, also known as the monument plant (Latin name: Frasera speciosa, Frasera for botanist John Fraser and speciosa meaning showy) is fairly common from 8,000 to 11,000 feet, though most summers you are lucky to see a handful in bloom. The large, oval-shaped, shiny green leaves grow all the way up the flower stalk, with clusters of white and green flowers poking out. The plant towers over mountain meadows, growing to a height of 5 to 6 feet.

We were supposed to be doing something useful that Wednesday night in the time slotted for herb class, like gathering much-needed plants for the shop while the short-lived summer was so generous. But all I could think about was getting back to Coal Bank Pass, over which I had sped July 4 en route to Silverton, eyes bugged, where the green gentian rose from the hillside like giant luminarias. There were hundreds of them.

“ No one knows why they have these banner years, where instead of three blooming across a couple acres, there are 300 blooming,” I told the apprentices as we drove up Highway 550, east-facing slopes just beginning to hurl their shadows across the road. “The green gentians are monocarpic, meaning they bloom once and then die.” I pause, taking quick inventory of interest levels, and seeing that the apprentices are with me, I give them this: “The average age of a flowering plant seems to be about 35-40 years, though at high altitudes they may wait until they are 75-80 years old to bloom. And then they die.”

We discuss the strategies of such an extreme life. Spending decades building up strength and energy in the roots allows for the one-time flowering to be spectacular, the green gentian literally giving its flower everything it’s got. And flowering, of course, is the biological purpose of a plant; ensuring that the parent genes, through seeds, will endure another generation.

“ There’s some!” I call out, pointing to the swaths of meadow laid out like a doormat at the feet of aspen stands south of Purgatory. Our first green gentian sighting buoys us for the rest of what seems like a long drive for the end of a full workday. As we rise in elevation, the cool air blows in the truck windows and settles around my neck and bare shoulders, the first respite from the mid-90 degree heat of town.

We arrive at Coal Bank Pass, sun sinking behind the double hump of Engineer Mountain, leaving its last light in the tops of the tallest Engelmann spruce. The slope below Engineer, usually covered by ski tracks in the winter, is lousy with green gentian. Like the tall, straight saguaro cactus that dominates Sonoran desert hillsides, the gentians are conspicuous rods of white against the green backdrop. I can’t stop exclaiming over the sheer numbers. The apprentices, becoming acquainted with green gentians for the first time, are duly impressed.

We stop in front of a mammoth plant, where a bumblebee squirms inside a flower, its bottom pulsating in the ecstasy of imbibing nectar. The four-petal flower beckons pollinators with its extravagant purple spots, known as nectar guides; the payoff is under two fringes of hairs that may serve to cool the nectar, keeping it from crystallizing. The leaves are found at intervals of 2 to 6 inches up the flower stalk, and at each leaf axil (where the leaf joins the stem), a cluster of flowers emerges. A 6-foot plant may produce as many as 1,400 flowers. Some shoot out horizontally, putting themselves in the path of sun, bees and other pollinating insects; others hang crowded against the 1 to 2-inch thick stalk.

We count, on this particular plant, six leaf axils whorled around the stalk with 10 to 15 flowers per cluster, creating approximately 78 flowers every 4 inches. “It’s like a botanical high rise,” Holly, one of the apprentices, comments.

We walk along the trail, green gentians above and below us, in front of us and behind us. We try and see if we can find any that are not blooming as we discuss the phenomenon.

“ It’s like some sort of collective consciousness,” one of the apprentices says. “Maybe it’s the drought creating urgency.”

The other mentions, “Maybe it’s something in the moon.”

We agree that it’s good to have some mystery. I point out other plants as we walk, explaining how they are gathered, processed and used for medicine. I am surprised at how interested the apprentices are in learning the local plants, asking me to quiz them on the plants we’ve already seen. I tell them repetition is the key, and they take this to heart. We are finally driven out by mosquitoes, nightfall and the girls’ respective rendezvous’ with boyfriends back in town.

A few days later, I am lucky to connect with botanist David Inouye, who spends his summers at Rocky Mountain Biological Laboratory near Crested Butte. For the past 30 years, Inouye has been studying Frasera speciosa. He believes that when the plants get to a certain age, anywhere between 20 and 80 years, they are ripe for an environmental cue that signals them to bloom. Inouye created this hypothesis somewhat by accident. He was watering a plot of about 100 wild green gentians for much of a summer, hoping that the increased water would spark a riot of blooming. It didn’t. He continued to water that plot the following year, again with no appreciable results. By the third summer he threw in the towel and left the plot alone, and the gentians flowered significantly more than in other areas across the mountains. He also discovered during those two summers of intense watering, that the plants pre-form leaves and flowers two years in advance. These observations led him to believe that the gentians that flowered in his plot had received an environmental cue two years prior to blooming, prompting their floral display. Inouye believes the cue is summer precipitation, rather than drought, though he’s not sure if it’s the amount of rain throughout the summer, or density of rain during a certain month, or another formula altogether.

If his hypothesis is correct, then the green gentians flowering this year were kicked into gear by rainfall during the summer of 2001. I checked my garden journal for notable events of 2001. This is what I found: 7/1/01 First rain of the season! Nice and heavy; 7/20/01 Seems to be raining hard about once a week since July 1st; 8/1/01 RAIN! Monsoon season has begun; big, fat, loud torrential thunderstorms! 8/16/01 Rained every day for three weeks straight now. Apparently the summer of 2001 was quite wet after all.

Inouye explains the potential benefits of the banner bloom years, even if they only occur every two to eight years. This mass blooming can actually thwart the actions of predators. Inouye says caterpillars may be the green gentian’s biggest predator, as well as a fly that only lays eggs on flowering green gentian stalks. The fly and caterpillar may produce a large number of offspring the year of the green gentian flowering because of large food supplies, but the following year, when the numbers of flowering plants dwindle, the boom-year offspring are left high and dry, and many will die. Pollinators, however, of which there are many for the green gentian, have a virtual all-you-can-sip nectar bar, without having to travel much during this monthlong bloom. Bumblebee populations are down because of drought, though hopefully the local explosion of miller moths will take up the slack.

Inouye says that currently, in the East River Valley, from Mount Crested Butte to Schofield Pass (approximately 10 miles), there are about 18,000 flowering green gentians. The progeny of the largest flowering population will probably not survive because of the proposed development of Crested Butte’s “North Village.”

“ Enjoy them while you can,” Inouye says of his beloved plants. He also notes that most of our mountain perennials are very long lived, and every time we bulldoze for development, not only do we encourage non-native plants to colonize the disturbed ground, but for those seeds that do survive to germinate, it may be many years, decades even, before they bloom again.

Inouye tells me that the green gentians had banner years in 1971, 1973, 1977, 1980, 1988, 1990 and 1996. I am surprised to hear that the green gentians had a big bloom in 1996. I was here, how could I have missed it? Then I remember that it was just my second summer in the area, I hadn’t yet been here long enough to see patterns in the mountains. Now I see there is yet another kind of extreme lifestyle: staying in a place long enough to forge membership in the communities of both humans and wild ones; learning the subtleties of place.







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