Beargrass -- Xerophyllum tenax

For the past fifteen minutes, I have been an unwitting pollinator. Arriving at my campsite, I throw off my backpack, a necessary burden on the long hike up this steep mountainside. I’m lightheaded and tired as I notice white dust covering my pants, sleeves, and the sides of my pack. It puzzles me as I set my breath and take time to recover, but looking out toward the open meadow, it clicks. This isn’t dust, but pollen from the field of flowering beargrass (Xerophyllum tenax) I just waded through to get here. After I set up my tent, I head back into the meadow to run my hand through the masses of inflorescences, large and comprised of many small white flowers at the end of four foot stalks. I smile as I look at my hand, covered in pollen, confirming my thought. I send it through the beargrass again before wiping it off on my shirt. This summer seems to have brought a particularly great bloom for this beautiful plant. The meadow is awash in white, mimicking the blanket of snow that covers it for more than half of the year. Looking back downhill, I can barely make out the path that I followed because of the dense growth of beargrass crowding everything. The plants along the trail, near the tree line, have used me to send pollen uphill. When I head out of here in a couple of days I will be used again, this time in reverse, helping to send pollen down, mixing genes. Not that this remarkable population of beargrass needs any help. Tens of thousands of them fill the meadow I am in and the hillside above me. My contribution to its reproduction is infinitely insignificant. But still it has put me to work.

In spite of its common name and deceptive foliage, beargrass is no grass at all. Instead, it is more closely related to lilies and is a member of the bunchflower family, Melanthiaceae, the same as trillium. The leaves are long, narrow straps, tussock-like, emerging from the ground in tufts, or basal rosettes, and are evergreen and rough. These hardened leaves allow beargrass to endure summer drought and the intense solar radiation to which they are exposed, while also guarding against winter freezes. Similar to many grasses, beargrass grows through rhizomes, underground stems which range around just below the surface. From protected nodes along these rhizomes, new growth is sent both upward, as leaves, and down, as roots. From each one of these leafy rosettes, a flower stalk will eventually emerge that is decidedly not grass-like.

Beargrass flowering is a somewhat complex. Floral displays occur every year in midsummer, but the intensity of the flowering varies from year to year. Isolated populations are heavily influenced by local climate and habitat factors, like how wet or dry the previous year was, or if a fire has come through recently. Like super blooms in the Californian desert following a wet winter, or oaks that experience occasional mast years when extraordinary seed production occurs, areas of beargrass tend to experience super blooms every few years with much poorer flowering during intervening years, though even poor flowering years can be impressive.

Though climate conditions are likely the primary trigger of localized super blooms, a latent biological cycle in beargrass also makes a contribution. Beargrass is semelparous, meaning each rosette that sends up a flower stalk will die in the same year after setting seed. Century plant (Agave americana) and, well known by anyone in the coastal northwest, Pacific salmon, are among many other organisms that also exhibit semelparity, dying shortly after their single attempt at reproduction. We humans are truly blessed. For beargrass, having semelparous (also termed monocarpic) rosettes is offset by the fact that it is grows so well through vegetative means. A single rosette, though it dies after flowering, is just one of countless rosettes that can arise from their tightly packed rhizomes. Though an individual rosette dies, younger rosettes are there to take its place and so the plant lives on. Each of these vegetative offsets will mature over many years before finally flowering and dying away themselves. And all the while, more are forming. The cycle will continue on and on, like human population, some dying, some being born, and most somewhere in between. Natural fluxes in the age distribution of rosettes in a population, a delayed response to recent climatic and landscape influences, certainly contributes to the triggering of super blooms.

Small and yet to open, the individual flowers are tightly packed at the end of dark red stalks.

You will find prime beargrass habitat where forest transitions to meadow, just at the tree line on open slopes throughout the Olympic Mountains, the Cascades of northern California, Oregon, and southern Washington, and east into the northern Rocky Mountains in Idaho and Montana. It is also at home in low elevation openings along the coast. Beargrass can carpet subalpine openings, acting as the dominant plant with smaller herbaceous wildflowers and shrubs weaving through their thick foliage. In Washington, subalpine fir (Abies lasiocarpa) and mountain hemlock (Tsuga mertensiana), satellites of the nearby forest, are dotted around in these meadows. Beargrass is fairly adaptable to different soil types, so long as water drains away quickly, but seems to prefer areas where the soil is thin, poor, and acidic. Abundant sunlight is required for massive colonization, but beargrass will also sneak into the shaded forests that abut their meadows.

Beargrass responds rapidly in the wake of a destructive fire. The wiry foliage, unprotected, is happily given as in offering to the flames which can destroy the surrounding trees and shrubs. Whereas these larger woody plants will take many years and decades to reestablish from seed, the rhizomatous beargrass will quickly re-sprout from nodes that have survived buried underground. For beargrass growing near or under the trees, a clearing fire brings great opportunity. Years of agonized growth, eking out a meager existence in the shade, thin and rarely able to scrape enough energy together to flower, will have been worth it as the beargrass that bided time in the forest will quickly colonize the new meadow, thriving for decades before the forest returns. Hiking up into a beargrass meadow, you always see the outlying forest dwellers first. I used to think of them as spindly things, ugly and only worthwhile in that they signaled that I was getting close to the real beargrass. But the more I think about it, the more I appreciate these plants. It’s a brilliant ecological strategy, just like young trees in deep forest growing so slowly, sometimes wider than tall, but staying alive in hope that a big tree might fall and open a spot in the canopy into which they might emerge. These beargrass are the risk takers, betting on an event that might not happen in their lifetime, for a chance to be in early on a boom.

Flowering starts from the bottom and works its way up.

Both humans and wildlife put beargrass to use. Small animals find shelter in the thick mats of foliage, nesting and traveling, hidden from predators and the elements. Deer and elk gorge themselves on the sweet flowers, evidenced by the numerous headless stalks found wherever beargrass grows. On a quiet morning, I watched a doe and two fawns eating their way through a meadow, the mom easily chomping away while the two little deer strained to reach the taller plants but mostly stuck to the smaller stalks, not quite masters of the meadow yet. Bears tear out clumps of leaves to use as bedding in their winter den, though they apparently don’t bother eating the flowers. During mass bloom years, the flowers provide an overabundance of food for insects, and the succeeding seeds provide for passing birds. Humans have long made use of the long stiff foliage for weaving baskets and hats, and more recently have found use for the unique leaves in floral arrangements. Beargrass is a desirable but difficult plant for gardeners. It is so slow from germination to flowering, taking five or more years, and somewhat finicky about where it will grow. But even though the wait for the first flower is long, the unique evergreen foliage can make a nice addition to a garden. At Chase Garden in Orting, Washington, a relatively large and healthy population grows on a well drained slope with no added nutrient or water. Intermingled with the much lower growing heather (Erica sp.), this beargrass is sun soaked much of the day but finds relief in the form of shade late afternoon onward. It was planted there decades ago and required almost no care with good flowering every other year. Hopefully the planting will continue to prosper for a long time to come.

Beargrass is an extraordinarily charismatic plant because of its unique and beautiful appearance. The massive, field-filling blooms displayed in spectacular surroundings make it an iconic plant of the mountainous northwest. It’s breathtaking to see in person, and each opportunity that I have had to be among them has left a mark on me. It goes like this: I wander the meadows, following the trails up and down, taking pictures, getting pollen everywhere. I laugh, knowing happiness, freedom, present and future. I stick my nose into one and deeply inhale the musky-sweet aroma, feel the softness of flowers and coarseness of leaves, then find a comfortable place for a long sit. I pull out my flask to take a nip of whiskey with cheers to beargrass, and soak it all in. When I leave, some of the pollen goes home with me, on my clothes and in my skin.