“I had the pleasure of knowing Bernard M’Mahon, in my youthful days. He was, I believe, one of those Exiles of Erin who sought and found a refuge in our country, near the close of the last century. In the autumn, I think of 1799, he passed some weeks at my native village of Dilworthtown, in Chester County, in order to avoid the ravages of yellow fever, in Philadelphia, where he resided; and in that rural retreat I first knew him. I renewed the acquaintance in 1802, 3, and 4, while attending the medical lectures in the University of Pennsylvania, by which time he had established his nurseries of useful and ornamental plants: and I ever found him an obliging, intelligent, and instructive friend. He was a regularly educated gardener, of much experience, and great enterprise. He gave the first decisive impulse to scientific horticulture in our State; and to him him we are mainly indebted among other favors, for the successful culture and dissemination of the interesting novelties collected by Lewis and Clarke, in their journey to the Pacific. When, in 1818, Mr. Nuttall published his Genera of North American Plants, he named a beautiful shrub “in memory of the late Mr. Bernard M’Mahon, whose ardent attachment to Botany, and successful introduction of useful and ornamental Horticulture into the United States, lay claim to public esteem:” and although the genus has been reduced by later botanists to a section of Berberis, it is generally known by—and I trust will long retain—the popular name of Mahonia.
“It was a well-deserved tribute of respect, from one who intimately knew, and could justly appreciate the merits it commemorated: and I am happy in the opportunity, even at this late day, to add my own humble and inadequate testimonial to that of so accomplished a judge of botanical worth, as Thomas Nuttall.”
Changes - History of Early American Landscape Design