Nurseryman Bernard MacMahon and the Oregon native plant with an Irish connection.


Mahonia aquifolium syn. Berberis aquifolium.
© Aislinn Adams 2008

Tall Oregon grape, Mahonia aquifolium- Oregon’s state flower and its Irish name!

I’ve always marveled at how something as fragile as a plant can end up thousands of miles from its original home: collected and pressed into herbarium specimens or more amazingly, kept alive on long transcontinental journeys and treacherous sea voyages.  Somehow they avoid destruction and are finally transplanted into a foreign soil and there, not only survive but thrive.

I must confess I feel a certain affinity with these well-travelled plants. I am also a transplant from a far off land having emigrated to the U.S. from Ireland. However, my journey was pretty uneventful and mundane when compared to the fortunes of these early pioneering plants and their adventurous collectors who often risked everything to bring them back.

As a horticulturist and botanic artist I feel not a small debt to these enduring plants and their collectors. So, when I post my botanical illustrations, instead of writing about their cultivation I prefer to write the human stories behind the plants. The story behind this week’s botanical illustration, tall Oregon grape, Mahonia aquifolium, contains all the elements of a good plant story but it also has another important attraction for me: it connects the place of my birth with my new home in Oregon.

Two scientific names for one plant!

The connection to Ireland lies in the second scientific name for this genus of shrubs. For some reason Oregon grape has two scientific names- Berberis and Mahonia. Generally speaking, botanists use the first name while horticulturists use the second. As a horticulturist I learned to name the genus Mahonia and even though I have been aware of both names for many years it has never bothered me which one was used. Now that I’ve discovered the Irish connection I’m more inclined to favor the latter.

Years ago in Ireland I chose Mahonia aquifolium for my first garden. Back then I didn’t give the plant’s scientific name much thought. It wasn’t until I moved to the Pacific Northwest and discovered Mahonia aquifolium growing in the wild that I began to wonder about its Irish-sounding name.

Irish Nurseryman Bernard MacMahon

That is how I discovered the Irish nurseryman Bernard MacMahon (1775-1816) . Maybe it was because MacMahon had to leave Ireland in a hurry that so little is known about his early life other than he emigrated (probably from Ulster) around 1796. (Some historians suggest that he fled government persecution due to his political leanings towards the United Irishmen.) Fortunately we know a lot more about his life in the U.S.

MacMahon Nursery and Seedhouse.

By the early 1800’s MacMahon had established  a successful nursery and seed business in Philadelphia where many of the up and coming young botanists of the day would gather (including William Darlington and Thomas Nuttall.) However, MacMahon’s main “claim to fame” was his popular gardening book The American Gardener’s Calendar– the first book of its kind to be published in the U.S. It ran to 11 editions and had many admirers, one of whom was President Thomas Jefferson. So impressed was Jefferson with The Calendar that he became a regular correspondent with MacMahon, often trading plants and seeds.

Lewis and Clarke’s Plant and seed collection.

1806, the year The Calendar was published was also the year that Lewis and Clark’s Corps of Discovery returned from the Pacific Northwest. As directed by Jefferson the expedition returned with a trove of plants and seeds collected along the way. Jefferson expected Lewis to publish their description as soon as possible.  Unfortunately, due to his untimely death, publication was delayed. The story of this famous plant and seed collection is an interesting but complicated one with many twists and turns and MacMahon’s, sometimes unwitting, role in its fortunes will be the subject of my next blog. In the meantime, for the purpose of this story, all you need to know is that the collection passed through the grasp of several individuals before finally arriving in the capable hands of MacMahon.

“Classified” seeds!

This was no ordinary collection.  Jefferson passed on the larger portion of the collection’s seed to MacMahon with strict instructions: as federal property he was forbidden to propagate any of the seeds for commercial use and the collection had to be kept secret while its description awaited publication. In spite of these restrictions MacMahon set to propagating and growing the seeds with great diligence and skill and  the plants flourished. He never really benefited from the plants commercially, nor from being able to advertise their existence at his nursery but in the end he was honored posthumously for his efforts. In 1818 Thomas Nuttall named this genus of shrubs for him in his publication The Genera of North American Plants. I suppose one could say the reward for his hard work, loyalty and discretion was immortality in a plant’s name- for which I am very glad – because every time I see this plant I feel the connection between Ireland and Oregon and the distance recedes.

Aislinn Adams

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