Izzy Acevedo seeks Phlox, and questions, in the Texas Hill Country, returning to the laboratory supplied with both.
It’s my second field season in central Texas, and this time I have the confidence and savvy that comes with a little bit of experience: I know how to watch out for the bull nettle and the fire ant mounds, which could leave me in blistery pain for days; I know the particular flick of the wrist it takes to catch Battus philenor, our favorite pollinator, in a butterfly net; I know the approximate length of time we can hover on a roadside looking for Phlox wildflowers before a concerned Texan property owner comes out to question us. Such are the markings of a Hopkins Lab field scientist.
Each morning, fueled by coffee and breakfast tacos, we hit the road in search of Phlox. We follow maps cobbled together in evening sessions on the couch, copying coordinates of sightings logged by our lab predecessors and the larger community of observers on iNaturalist. Some of these points lead us into fenced dead ends and unlikely ditches, but at other spots we are rewarded with the sight of pink poking up through the green and brown of the roadside. We greet the Phlox and their usual cohabitants with the joy of meeting old friends, the familiar firewheels and paintbrushes, the pinkladies and the yarrow.
There are friends to be made with caution, too, crouching in these overgrown ditches at the wild margin of ranch and road. We tiptoe around teetering piles of rotting juniper wood, a humid home for stinging scorpions. We carefully skirt a rattlesnake coiled defiantly on the hot asphalt of the emergency lane. We play frogger with passing trucks to save a few turtles making their way across the double-yellow.
Key to our interest in one Phlox species, P. drummondii, is the spatial gradient along which its color changes from light blue to dark red, a key adaptation that prevents its cross-pollination with highly similar species Phlox cuspidata. We drive this cline until swathes of bluish-purple turn into a patchwork of dark plum and pale pink and finally to a deep rose red, the same species looking a sister to purpletop verbena and blue-eyed grass and scarlet sage within a couple of miles.
Everywhere we find Phlox, we are followed by the fluttering shadow of the pipevine swallowtail, Battus philenor. We watch as it gently alights on purple flower after purple flower, pausing the beat of its wings to kiss the opening at the center of each corolla, graceful and methodical as it dives for nectar with its pollen-covered proboscis. It is easy to see how a choosy butterfly moving only between flowers of the same color would no longer transfer pollen from a light blue Phlox cuspidata to a dark red Phlox drummondii.
We venture further west to find more close relatives of P. drummondii, who will help us in our quest to understand the species interactions that lead to evolution. Moving into the Texas Hill Country, cow-dotted pasture gives way to rolling hills laced with teeming cliffs and rushing creeks; never-ending networks of highways give way to winding county roads. Rather than crossing a lazy stream of trucks, we mount the ridges of bald cypress roots and wade through a slippery green current to our target population. These Phlox rest in the rocky outcrop between meadow and river, perhaps not so unlike the perimeter of pasture and road.
Even if the species in this family are similar enough to trick a butterfly, each has obvious particularities, personalities. Soon we come to know by sight or sense what kind of landscapes will be home to our study species, a kind of empathy for their wants and needs. “Pilosa wouldn’t grow there,” we say, with the intuition of familiarity; or, “villosissima would like this, it must be here.”
Even if the species in this family are similar enough to trick a butterfly, each has obvious particularities, personalities.
At each site we come into intimate contact with Phlox, meeting them with careful and tender touch. We bend low to the earth, letting ourselves be engulfed by the grasses and grasshoppers, and run our hands through to comb apart the vegetation until an individual Phlox stands aside from the other stems. With our fingertips we test the calyxes for the taut, resistant flesh of fruit swollen from pollination; upon finding one, we push through the stem with a fingernail and tuck the fruit into a card envelope, where it will dry into a pod with three neatly packaged seeds to be planted in the greenhouses. We snip cuttings from the fresh vegetation of the perennial Phlox, who are no longer flowering, and wrap them neatly in paper towels moistened from our water bottles or the rain on the windshield.
We scrape at the ground with our hands to pull aside mats of grasses, clearing the way to collect soil with a trowel. We can see and feel in the grit stuck under our nails that the soil around Phlox drummondii is light and sandy, while P. cuspidata tends towards a muddier and darker substrate, and P. pilosa is usually found in the richer soil at the woodland edge; other times we collect what feels like more rock than soil, chunks of limestone around the roots of P. roemeriana and water-smoothed pebbles from the riverine ridges where P. villosissima grows. Later, results from the soil testing laboratory will confirm the differences in moisture, minerals, and nutrients that we feel on our skin.
The final day of work arrives, our bodies sweat-stained and sun-bruised, suitcases packed full with seeds and soil samples. Seen from the road, the lush green hills dissolve into markers of excess; the views moving across our windows like movie reels suddenly reflect a much different way of touching a landscape, a relationship not of empathy but of extraction. We pass a couple of dry creek beds, an irrigation reservoir that’s been drained to blanched stone and rusty shipwrecks; a few highway minutes later, the green transforms into the sprinkler-fed lawns of new housing developments. By the time we reach the airport in Austin, we have only seeds, photos, and the feeling in our fingers to remember the rich landscapes that give us Phlox.
Back in the Weld Hill greenhouses, we nestle our newly collected Phlox seeds into soil, carefully mixed and moistened with the memory of the Texan substrate in our palms. As they grow, we are challenged to imagine ways of creating those conditions that their parents in the field so enjoyed. How could we reflect the shifting humidity of those open fields as the blazing sun goes down or a day of rain cuts through the drought? How do we compact the soil in a way that might mimic the tangled roots of fellow wildflowers, the footsteps of deer, the wheels of a farmer’s mower? How do we, wielding sharp metal prongs, pollinate with the gentle touch of a butterfly’s proboscis?
There are no perfect answers to these questions, only attempts at giving thought and care to the spaces where these plants have grown and thrived, the environments that make up their history—just as I would for any human companion. With an intimate understanding of the landscapes where they came from, I can better grow and learn from the Phlox right here at the Arboretum.
Izzy Acevedo is a research technician in the Hopkins Lab at the Arnold Arboretum.
From “free” to “friend”…
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