BOX-ELDERS, REAL AND SO-CALLED 135 
the Midland plant or, as Britton has it, the aggregate of Midland 
and Rocky Mountains plant which he called Acer interior,* not 
mentioning synonyms, and thus leaving readers to suppose that 
it is in every sense an entirely new plant, never previously referred 
to. 
The plant I shall call Rulac Nuttallit could hardly have had 
the same type as Britton’s plant, as it is not likely that Nuttall 
as early as 1818 had penetrated as far as the mountains. We 
know, however, that in 1810 he made a journey west along the 
Ohio river almost solely to look up a new genus of plants typified 
by Collinsia verna published in 1817, and it may have been that 
he met with our midland Ruiac on this trip west of the Alleghany 
mountains. At all events his description, incomplete as it certainly 
is, can only point to our midland Box-elder. He gives as the 
habitat of the tree: “ Northwestward on the banks of the Missouri 
to the mountains?” I append here the synonymy of the Box- 
elders as fully as I have been able to ascertain it, or as is deemed 
necessary for the understanding of the various limitations of 
species already referred to. 
Ruxtac Adanson, 17637. 
Negundo John Ray, 1688{ per errorem. 
Negundo Ludwig-Boehmer, 1760§ haud Negundo Garciae 
et Acostae, 1567 et 1593,|| vel veterum. Est enim 
Vitex Negundo Lann., 1753. 
Negundium Rafinesque, 1808. 
Acer Linnaei pro parte.** 
* The specific name interior would seem to have been ill chosen. The 
obvious meaning of the Latin word is ‘“‘internai,’”’ ‘inside oj.”’ It would be 
difficult to imagine what a plant could be inside of and an internal or 
interior maple is an unthinkable thing. It was probably meant for meso- 
chorum or midland, the Greek term being the only available one, as the Latin 
synenym mediierraneum would obviously refer to a European habitat. 
+ Adanson, M: Familles des Plantes, Vol. I1., (1763), Pp. 283, 
¢t Raii, J. Historia Plantarum, (1688), p. 1795. 
§ Ludwig-Boehmer, Definitiones Plantarum, (1760), p. 508. 
|| Garciae ab Horto et Acostae, Arom. et Simplic. ex Car. Clusio, 1593. 
Cap. Ill. De Negundo. 
§ Rafinesque, C. S. Med. Rep. Vol. V, 2nd Hexade (1808). p. 352, 
also Desvaux, Jour. de Bot., Vol. II. (1809). p. 170. 
** Linnaei, C. Species Plantarum, (1737), p. 1056. Linnaei, C. Genera 
Plantarum (1737), p. 112, et (1754), P. 474- 
