Thomas Jefferson Papers

To Thomas Jefferson from Bernard McMahon, 17 January 1809

Philadelphia Jany 17th. 1809

Dear Sir,

I duly received the Gloucester nuts, and am extremely obliged to you for them; the more so as I have for two or three years past paid particular attention to the Juglans family, and have not been able to make out, to my satisfaction, more than 7 United States species, viz.

1. Juglans nigra, Lin.
2. Juglans cinerea Lin }
oblonga Du Roi & Mill.
cathartica, Michaux Junr.
3. Juglans olivaformis Mich. }
pecan, Marsh. & Muhl.
cylindrica, Link.
4. Juglans sulcata Willd. }
mueronata, Mich.
amasa, Muhl. & Mich Jr.
alba minima, Marsh.
5. Juglans alba, Mich, nee Lin. }
alba avata, Marsh.
squamosa, Mich. Jr.
6. Juglans tomentosa, Mich. }
alba Lin. & Gaertner
7. Juglan compressa, Gaert. }
alba odorata, Marsh.
porcina, Mich. Jr.

With the 7th. species, Willdenow has confounded the 5th. or alba of Michaux, our tree Shell-bark; but I am inclined to believe that the J. glabra & J. obcordata, of Willdenow’s edition of the Sp. plan are but mere varieties of the above 7th. or compressa. I have seen and examined the trees at Mr. Hamilton’s from which these two species are said to have been made, by Doctor Muhlenberg, (the obcordata of Muhl. & Willd. Mr. Hamilton calls ficiformis) but I really can find no difference, between either, & the compressa, except a trifling difference in the shape of the perecarpum, which is not at all uncommon in every species of the genus.

If the Glocester nut belongs to any of the above species, it must be to the 6th. the alba of Lin. & tomentosa of Mich. The latter name I would prefer, on account of its being discreptive. The alba of Mich. I never saw with more than five leaflets; consequently it cannot or ought not to be given as a synonym to compressa, which Willdenow describes, “J. foliolis septenis, &c” and which is just.

I wish to know if the Tarragon roots I sent you have succeeded as I can send you a supply in due time this season if they failed.

I am very anxious to learn when Governor Lewis may be expected here, as I have detained a man in my house upwards of twelve months, drawing & describing his plants, which he left with me for that purpose; this was accomplished in May last, as far as it could be done in the absence of Govr. Lewis, and he told me on his leaving this City he expected to be here again in that month. This man, who is completely adequate to the task, is becoming very uneasy, and I wish him not to leave the neighbourhood till the arrival of Mr. Lewis, by whom particular instructions only, he can finish the drawings of some very important, but imperfect specimens.

I am sorry to give you so much trouble; hope you will excuse me, and am Sir,

With Respect and Esteem, Your Sincere Wellwisher.

Bernd. McMahon

DLC: Papers of Thomas Jefferson.

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