1422 _ ARBORETUM AND FRUTICETUM. PART III. 
other masts, or acorns; the-only species that was known to the Romans having been the 
Jiglans régia, or common walnut-tree. 
Description. Large trees, with pinnate leaves, coarse-grained wood, and 
fruit, in one species at least, much esteemed at the dessert, and valuable for the 
oil which it contains. 
General Observations. The trees belonging to this order bear, with only 
two or three exceptions, so close a resemblance to one another in their 
young state (in which state alone most of them are to be seen in Britain), 
that we have been unable to satisfy ourselves as to what are species, and what 
are only varieties. In pursuance of our idea, that no plant can be truly a 
species, that is not readily distinguished from every other, in every stage of 
its growth, and at every season of the year, we should say that there were 
not more than two species of walnut hitherto discovered, either in Europe or 
America; viz. Jiglans régia and J, nigra: and three species of Carya; viz. C. 
amara, C.lacinidsa, and C. squamésa. We submit this opinion, however, with 
great deference, having formed it chiefly from inspecting the young plants in the 
Horticultural Society’s Garden, in the collection of Messrs. Loddiges, and from 
observing the great variety of foliage distinguishable in a bed of seedlings of any 
of the American sorts; we shall therefore adopt the descriptions and figures 
of Michaux, and leave the truth to be discovered by time and future observa- 
tion. Previously to describing the species of the three genera, Juglans, Carya, 
and Pterocarya, we shall quote Michaux’s introductory observations; pre- 
mising that this author includes both Juglans and Carya under the genus 
Jiglans; the genus Carya, as we have seen in the generic characters above, 
having been separated from Juglans by Nuttall, chiefly on account of a tech- 
nical distinction in the fruit. ‘The walnuts of North America,” Michaux ob- 
serves, “ appear to present characters so distinct, as to require their division 
into two sections. These characters consist principally in the form of the bar- 
ren aments, or male catkins; and in the greater or less rapidity of growth in the 
trees. The first section is composed of walnuts with single aments, and in- 
cludes two American species: the black walnut (Juglans nigra L., fig.1260. in 
p-1436.), and the butter-nut (.J. cinérea L., fig.1262. in p.1439.); to which is 
added the European walnut (./. régia L.., fig. 1257. in p. 1425.). The second 
section consists of such as have compound aments, and comprises eight spe- 
cies: the pacane-nut hickory (Carya oliveférmis Nutt., fig. 1263. in p.1442.), 
the bitter-nut hickory (C. amara Nutt., fig. 1264. in p. 1443.), water bitter- 
nut hickory (C. aquatica Nutt., fig. 1265. in p. 1444.), mocker-nut hickory 
(C. tomentosa Nutt., fig. 1267. in p. 1445.), shell-bark hickory (C. alba 
Nutt., fig. 1269. in p. 1446.), thick shell-bark hickory (C. suleata Nutt., 
fig. 1271. in p.1449.), pig-nut hickory (C. porcina Nutt., fig. 1273. in p.1450.), 
and nutmeg hickory (C. myristiceférmis Nutt., fig. 1275. in p.1451.). The first 
three species of the second section bear some relation to those of the first 
in their buds, which are not covered with scales. For this reason, I have 
placed them immediately next, beginning with the pacane-nut hickory, which, 
by its numerous leaflets, most nearly resembles the black walnut and the 
butter-nut, the buds of which are also uncovered. Throughout the United 
States, the common name of hickory is given to all the species of the second 
section. This common appellation is due to certain properties of their 
wood ; viz. coarseness of grain, anda reddish colour in the heart-wood, 
which, however modified, are possessed by them all, in a greater degree than 
by any other tree of Europe or America. These species exhibit, also, a 
striking analogy in their forms and in their leaves, though they differ in the 
number and size of their leaflets. To these sources of confusion must be 
added another in the fruit, which is often so various in its appearance, that it 
is easy to mistake the species to which it belongs. It is not, then, on the 
most remarkable differences alone that our distinctions must be founded ; 
recourse must also be had to an examination of the shoots of the preceding 
year, y the buds, and of the aments.” (Miche. North Amer. Sylva, vol. 1. 
p. 139. 
