Ungnadia (the character of which Endlicher has not yet published,--the last plate in the “Atakta”) was named in memory of Baron Ungnade, once an ambassador from Austria to Constantinople or Persia, I forget which, and the first to introduce Æsculus Hippocastanum into Europe,--hence the propriety of the name. Endlicher is soon to publish the description in the “Annals of the Vienna Museum,” which work, with the “Iconographia Generum Plantarum,” he has promised to send to Hamburg for me, along with the parcels of plants given me. We have studied the new Loganiaccous plant from Florida. It proves, as Brown guessed, near his Logania § (or Gen.) Stomandra, but extremely distinct from that or any other genus, by the character of the style which Decaisne first noticed. Endlicher is to give a figure in “Iconographia Generum Plantarum,” and the description has gone to the printer in one of Endlicher’s articles in the “Annals of the Vienna Museum,”--Cœlostylis Loganioides, Torr. & Gr. Can’t we get more of it? Has Leavenworth found it? I have been looking over the “Reliquiæ Hænkeanæ,” and examining what specimens of the collection from North America they have in the Vienna Herbarium. Endlicher goes this week to Carlsbad to recruit his health, stopping a day at Prague. He has kindly taken a list of my desiderata of the species published in that work, and I hope to get some bits of them. I have copied so much from the work that we can get along even if I do not see it again, but as I was about to purchase it, Endlicher suggested that he should see if Presl himself has not a copy left for us. Following this hint I have sent by Endlicher a copy of the “Flora” to Presl,[106] in nomine auctorum. There is a new genus of Presl in Loaseæ (Acrolasia) from Mexico, which may be Nuttall’s. The most curious thing is a new genus of Datisceae from Monterey (why have none of the other collectors found it?), called Tricerastes; very interesting. I find from all inquiries that it is very difficult to find Nees von Esenbeck[107] at Breslau, especially in the summer. He is a queer stick altogether, is not well satisfied with his situation at Breslau, and spends the greater part of his time at a little place high up in the Riesengebirge, studying Hepaticæ. I have bought Grisebach’s new “Genera et Species Gentianearum,” and have been studying it on my way in the steamboat. It seems very well done, particularly his preliminary matter on structure, affinities, development, geographical distribution, etc., which is very interesting. It is very carelessly printed. Our well-known “Tuckerton,” in the pine-barrens, figures under the form of “Juckerten”! Let this suffice at present. SALZBURG, June 10.