Forest Service Stories: The Discovery and Identification of Lomatium ravenii ‑ a Test of Botanical Resolve

This is a Lomatium ravenii var. paiutense
by Gene Yates, then of the Malheur National Forest

Raven’s lomatium (Lomatium ravenii Mathias; Constance), a plant previously thought to be extirpated from Oregon, has been discovered growing in six locations on the Malheur National Forest.  Specimens collected on the Prairie City Ranger District were verified recently by Dr. Lincoln Constance, Professor Emeritus at University of California, Berkeley, a noted expert in North American Apiaceae.  According to the Oregon Natural Heritage Program, this plant, endemic to the northern Basin and Range in California and Nevada, was believed extinct in the Oregon portion of its historical range in Harney and Malheur counties.  The new discoveries are located in southern Grant county, well separated from the Nevada populations, growing in stiff sagebrush communities characterized by low plant cover and very shallow soils.

This noteworthy datum was not the result of a cavalier field identification during the course of an afternoon’s serendipitous botanizing.  In fact, the challenging taxonomy of Lomatium had concerned botanists fumbling with this plant’s identity for nearly four years.

In 1989, Greg Lind, botanist with the Malheur, observed this curious umbel growing in two locations on the Prairie City Ranger District.  The plant was collected, pressed, and labelled, for the moment, as “Lomatium sp.” to be dealt with more seriously later. (Greg later explained that the winter provided ample time for such challenges).

In 1990, I joined the Prairie City District staff and was the beneficiary of Greg’s vast knowledge and guidance while learning the flora of the Blue Mountains.  Greg had an insatiable appetite to know all the plants he encountered in the field and Lomatium was no exception.  One day that summer the mysterious lomatium (Lomatium x) was again collected and that evening we both took a crack at identifying it.  I had little success after repeatedly going through the floras.  In Vascular Plants of the Pacific Northwest, it would key fairly well to L. nevadense, but the description in the text did not match too close, nor did it bear much resemblance to what we had been calling
nevadense locally. Greg noted that if one could ignore the white color ofthe petals, the yellow‑flowered L. foeniculaceum was a decent fit.  Neither of us were comfortable with these identifications, though.  Despite numerous references, one stereomicroscope, and a hand‑honed micropoint tweezers, the identity of this plant still eluded us.  Perhaps better minds than ours could help.

The following winter, Greg sent specimens of Lomatium x to Oregon State University and Eastern Oregon State College.  Both replied that identification was difficult due to insufficiently mature fruits, an important character for distinguishing Lomatia.  However, the material was tentatively identified as L. nevadense, a morphologically variable species.  This we haughtily dismissed for reasons stated above.  Yet, we were no closer to the solution.

The 1991 field season was lost to me to pursue this question further as the fickle nature of Forest Service budgets had me working a nonetheless memorable summer for the Deschutes NF in Bend, Oregon.  But, the following autumn, I was back on board the Malheur and I had not forgotten this plant.

At this point, I should state that some of our frustration with this plant’s identity could be traced to the tools we employed to pry it from the ground. Our small “dandelion weeders,” which offered light weight, portability, and reasonable utility, proved less capable in the shallow, stony soil where Lomatium x is found.  Root material is generally favored when collecting
botanical specimens, and we had been gathering, as best we could, what seemed a representative portion of an apparently slender taproot with our mysterious umbel.

Enter Dr. Dale McNeal, Professor of Botany at the University of Pacific, Stockton, CA.  In May of 1992, Dr. McNeal was passing through eastern Oregon forests collecting wild onions (Allium sp.) to help resolve taxonomic confusion in the genus for the Forest Service.  I was fortunate to guide Dr. McNeal to collection sites on the Malheur.  I took him to one area that also happened to harbor the mysterious Lomatium x.  Dr. McNeal was not a timid plant collector; he carried with him oversize plastic bags that would accommodate a sizable volume of material, and to help fill these bags, a large (some 30 inches long) pick‑like implement, which he affectionately referred to as “The Terminator.”

Dr. McNeal presented quite a formidable image wielding The Terminator in one arm above his head as he poised his 6’‑4″ frame over the unwitting onions.

Opportunity is seldom a lengthy visitor.  “Would Dr. McNeal kindly liberate some specimens of that curious little umbel yonder?”  Obliging, Dr. McNeal set to work.  When the debris settled, I beheld an astonishing sight; deeper in the substrate below the “taproot,” Lomatium x was equipped with tubers!

Now, for those readers unaccustomed to navigating the fog‑shrouded seas of Lomatium taxonomy, the morphology of the underground portions is one character used to distinguish groups of species in dichotomous keys.  Some species have a slender taproot, as I thought to be the case in Lomatium x, while others have variously thickened, shapeless or globose, fleshy “tubers.”  I had been
following, erroneously, the “taprooted” leads in the keys.

Armed with this essential new datum, fresh material, and envigorated resolve, I dashed back to the arsenal of floras at home.  Following the “tuberous” leads in the key, then, led me to a small group of species, none of which, unfortunately, bore any resemblance whatsoever to the material at hand.  I was shipwrecked on the damn genus’ reef of seeming taxonomic futility.

“A salmon,

Green‑black, mottled white,

Hook‑jawed, and eyes pecked out,

Lay washed up onto a riverbank

Lapped by the waters of the wrong stream.”

Once my attitude was again sailing the clear blue waters of optimism, I reasoned that my plant [I was becoming quite possessive (obsessive?) by now] might not be included in Vascular Plants of the Pacific Northwest, that perhaps it was a Basin and Range species that had sloshed up onto the slopes of the adjacent southern Blue Mountains.  The Intermountain Flora had not yet published the volume dealing with the Apiaceae, the plant family containing Lomatium, and I had no other references that dealt with southeast Oregon.  So on a recommendation, I mailed some material to Dr. Lincoln Constance at Berkeley.

Dr. Constance’s prompt, friendly reply was very encouraging, if not entirely conclusive.  He offered two possibilities: Lomatium ravenii or an undescribed relative in the L. foeniculaceum‑L. nevadense group.  A new species! Wow! What a development that would be.  When my pulse slowed I researched the former alternative.  L. ravenii was not recorded in Vascular Plants of the Pacific Northwest, nor was it mentioned in Peck’s A Manual of the Higher Plants of Oregon, nor Abrams’s Illustrated Flora of the Pacific States.  Out of curiosity, I looked into the Rare, Threatened, and Endangered Plants and Animals of Oregon to see if it was a species of concern tracked by the Oregon Natural Heritage Program.  To my astonishment, it was listed as possibly extirpated from the state, having once occupied sites in Harney and Malheur counties.  To discover an “extirpated” species seemed nearly as thrilling.  But the final answer would have to wait.  Dr. Constance’s uncertainty was the result (again) of immature fruits.  It was September and I wouldn’t be able to collect properly‑fruited material until the following summer.  Imagine the winter‑long suspense.

With the utmost conviction, excellent material was gathered this past June and sent to Dr. Constance with the results announced at the outset of this article.  For several days, Dr. Constance thought he might be handling a new species before settling on Lomatium ravenii.  In the end, he could not distinguish my plant when compared to L. ravenii material from locations other than the type.  Of note, he found the tuberous habit of L. ravenii more interesting than what “just another Lomatium” find might have been.  Dr. Constance remarked that both the describers and Mark Schlessman, the monographer of the tuberous Lomatia, had overlooked this character of the plant’s subterranean nature.

What lesson, then, can be learned from this story?  Don’t let the curious and unknown slip through any cracks in your botanical integrity, even when confronted with chronic taxonomic setbacks; and, when concerning Lomatium, perhaps it is best to “speak softly and carry a big pick.”

Note from Sharon: any randomness in italicizing should be attributed to me, not the author; while hunting for a photo I ran across a more recent paper on the taxonomy here.

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