Solidago nemoralis var. nemoralis

Vol.SX
Pi,ATE N: 4.
SOLI DAGO NEMORALIS.
GROVE GOLDEN-ROD.
NATURAL ORDER, COMPOSITE.
Solidago nemoralis, Aitou.—Stem often corymbose at the summit; leaves spathulate-oblong and obVanceolate, renate
serrate, or entire, roughish-pubescent. Darlington’s Flora Cestrica. See also Gray’s Synoptical Flora, Gray’s Manual
of the Botany of the Northern United States, Chapman’s Flora of the Southern United Stales, Wood’s Class-Book
of Botany, and Britton and Brown’s Illustrated Flora.
The plan of this work is to give in the first
place pictures of our native flowers, botanical -
ly accurate, and as nearly perfect artistically as
the drawings can be made,—and in the next
place to take them as object lessons in the
broad field of human interest wherein the plant
illustrated may have a share. • In this instance,
the description of the pretty golden-rod illus-
trated is taken from the local Flora of Chester
Count}-, Pennsylvania, by Dr. Darlington,
because the specimen chosen for the drawing
grew in the adjoining county,—and, mainlv
to draw attention to the different methods em-
ployed by botanists in describing plants.
The one botanist, above all, who has studied
the family of the golden-rods, is Professor Asa
Gray. In his ' ‘ Synoptical Flora of North
America,” he describes seventy-four species,
besides a large number of varieties so marked-
ly distinct from their parent species, as to be
worth}’ of distinctive botanical names. His
description of the species under consideration
is as follows: — “ Mostly low, with a fine and
uniform clos“ pubescence either soft or (in age
and in dried specimens) minutely scabrous :
leaves from spatulate-obovate to oblanceolate or
somewhat linear; upper entire and small (half-
inch or more long) ; radical and lower cauline
sparingly serrate: thyrsus and its compact
racemiform clusters secund, commonly re-
curved-spreading: heads two or three lines
long: bracts of the involucre oblong-linear or
narrower, obtuse, smooth and glabrous: flowers
(appearing rather early) deep yellow: rays 5
to 9, usually more numerous than the disk-
flowers: akenes closely pubescent.” The dif-
ference in the length of the two descriptions for
the same species is striking, lint the larger
number of species in Dr. Gray’s work, makes
a different method of treatment necessary. Dr.
Darlington has but sixteen species to describe
to us, while Dr. Gray has seventy-four. We
speak of artificial systems of botany, and of
natural systems. But all systems are made up
of both classes. Thoug^i we can arrange plants
so that there are groups with so close affinities
that we can place them in orders, genera,
and species, we have to use artificial lines in
dividing them. This is particularly true of
species. No one can positively define a spe-
cies. The descriptions are merely compara-
tive. For all the elaborate detail of Dr. Gray,
no one could positively identify the Solidago
here outlined if he had never seen one of the
seventy-four species described. He would have
to see others, or compare the plant with her-
barium specimens before absolute certainty
could be reached. If there were but two
species of golden-rod, “ flowers few, spieate,”
and "flowers numerous, eorymbosely panicled”
would be considered a valid description for
either. But such a brief description would not
entitle an author to a name for a seventy-fifth
species, where seventy-four had already been
described. We learn from this that the
methods of description are in the main artifi-
cial; are dependent 011 the number of species
in the genus to be described; and that there is
nothing definite that will cover the idea of a
species in nature.
A large genus, like Solidago, has to be divided
into artificial sections, in order to make des-
criptions intelligible. In the limited list of
Darlington’s Flora Ccslrica, he would first
make a section with the racemes secund, —that
is, the (lowers all turned to one side, and spread-
ing* out from the rachis or common peduncle or
even recurved. Then there would be sub-sec -
(49)
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Ty WU)
J 01 ''Y IN 1987
NEW YORK BOTANICAL GARDEN
02355332
ÜLrA'.JlV i > i V.
HeT-; HARiUM.