Bulletin - United States National Museum - Smithsonian Institution

48 FLORA. OF WASHINGTON AND VICINITY.
ber of species, but of individuals, which give any particular flora its
distinguishing characteristics to all but systematic botanists; and it is
also upon this that in the main depends the commercial and industrial
value of the plant-life of every region of the globe. It is often the
omnipresence of a few, or even of a single, abundant species that stamps
its peculiar character upon the landscape of a locality. This is to a far
greater extent true of many other regions, especially in the far West,
than it is of this; the vegetation of the rural surroundings of Washing-
ton is of a highly-varied character, as much so perhaps as that of any
other part of the United States ; and yet there are a comparatively few
species which from their abundance chiefly lend character to the land-
scape and really constitute the great bulk of the vegetation.
The most prominent, if not actually the most numerous, of these are,
of course, certain trees, and notably several species of oak. Probably
the most abundant tree everywhere here, as in nearly all parts of the
country, is Quercus alba, the white oak; but Q.Prinus, the chestnut oak,
Q. coccinea, the scarlet oak, Q. pahistris, the swamp oak, and Q.falcata,
the Spanish oak, are also exceedingly common. The most abundant
hickory is Carya tomentosa, the mocker-nut. Liriodendron Tulipifera,
the tulip-tree, often improperly called white poi)lar, besides being one of
the commonest trees, is the true monarch of our forests, often attaining
an immense size. It is a truly beautiful tree, whose ample foliage well
warrants the recent apparently successful experiments in introducing it
as a shade-tree for the streets of the city. Among other common trees
may be mentioned the chestiuit ( Castanea vulgaris, Lam., var. Americana,
A. DC), the beech {Fagus ferruginea), the red maple {Acer ruhrum), the
sycamore {Platanus occidentalis), the red or river birch [Betula nigra), the
white elm ( Ulmus Americana), the sour gum {Nyssa^ midtifiora), the sweet
gum {Liquidamhar styracifiiia), the scrub pine {Pinus inops), the pitch-
pine (P. rigida), and the yellow pine (P. mitis).
Of the smaller trees, Cornus florida, the flowering dogwood, and Gercis
Canadensis, the red -bud or Judas tree, are very abundant and chiefly
conspicuous in the spring from the profusion of their showy blossoms;
all three species of sumac are common; HamamclisVirginica, the vf itch-
hazel, and Viburnum prunifolium, the black-haw, abound; Sassafras offi-
cinale, the sassafras, Castanea pumila, the chinquapin, and Jimiperus
Virginiana, the red cedar, also belong to this class.
Of the smaller shrubby vegetation we may safely claim as abundant
Cornus sericea and C. alternifolia, the silky, and the alternate-leaved