■- [LONG OSLANB .
BOTANICAL tOblETY
NEWSLETTER l&v'

September - October 1992 Vol. 2, No. 5

GUIDE TO THE GOLDENRODS OF LONG ISLAND, NEW YORK

by,

Eric E. Lamont ,

586-H Sound Shore Road, Rlverhead, N.Y. 11901

INTRODUCTION. Goldenrods were formally
included in the genus Solidago by Carl Linnaeus in 1753.
The scientific name is from the Latin solidus, meaning "to
make whole or- strengthen;" probably in reference to
medicinal properties described by ancient herbalists. In
1818 Thomas Nutlall first split out a distinct subgroup of
goldenrods (which included species with resin-dots on
narrow leaves and a flat- topped inflorescence), and proposed
a new genus Euthamia . Traditionally, taxonomists have
included Euthamia as a distinct section within Solidago;
recently, however, many synaniherologists (boLanists who
study composites, including goldenrods) recognize the
distinct genus Euthamia.

The genus Solidago consists of about 100 species in
North America, 28 species in New York, and 19 species
on Long Island. The genus Euthamia consists of about 6
species in North America and 3 species in New York, all
of which have been reported from Long Island. Only four
species of Solidago and only one species of Euthamia
occur in all of Europe, north Africa, and western Asia.

The goldenrods as a group are easy to recognize, and
some species are also fairly distinctive. But most species
arc separated by technical characteristics (because features
of the leaves, stems, and flowers arc very variable), often
making identification difficult. Even professional
botanists do not agree on just how many species there are
nor how they may be separated. Moreover, some species
certainly hybridize, yielding intermediate plants which add
to the confusion. Intcrgeneric hybrids between Solidago
and Aster also occur and have been placed in the genus
Solidaster (from the names of the parents).

PROGRAMS

See back of new letter for information.

The following guide to goldenrods has been prepared to
help the interested amateur identify the 22 species reported
from Long Island. The key is not overly technical. For
example, there are over 40 different terms that describe the
different types of plant hairs, the key uses only one:
"hairy". Conversely, die term "glabrous" technically refers
to a surface devoid of all vestiture; the key uses the non-
technical term "smooth." Unfortunately, the technical
terms are more accurate than the colloquial ones, and
therefore the key is imprecise in several areas.

The key is based upon several traditional keys found in
major manuals of North America flora. Therefore, alter
the key to L.I. goldenrods is mastered, the transition to
technical keys should be relatively easy.

Since a few unavoidable technical terms are used in the
key (inflorescence, involucre, petiole, etc.) reference to
other texts and manuals is recommended.

Euthamia gymnospermoides \=So!idago g.]
a very rare goldenrod from Li., not recenlly
observed. Illustration from Fisher (1 988),

Long Island
Botanical Society

September - October 1992

Page 1

KEY TO THE GROUPS OF SPECIES

1. Inflorescences axillary:

flower heads in clusters from axils

of ordinary foliage leaves Group I

2. Inflorescence thyrsoid:

flower heads in erect, compact, terminal
clusters; inflorescence cylindrical, longer
than broad; the branches of the inflorescence

never in curved, one-sided clusters Group II

3. Inflorescence paniculiform:

flower heads produced on one side only

of a spreading, usually recurved branch Group III

4. Infloresce'nce corymbiform:

flower heads forming a flat-topped or

convex-topped, inflorescence, resembling

a candelabra or branched candlestick Group IV

Group 1
Inflorescence

Group II
Inflorescence

Group 111
Inflorescence

Group IV
Inflorescence

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Botanical Society

GROUP I

A single species (frequent)

S. caesia

GROUP II

1 . Stem hairy

2. Ray flowers yellow

3. Stem finely hairy with minute

spreading hairs; bracts of involucre
very narrow, less than 0.75 mm wide

at midlength (frequent)

3. Stem coarsely hairy; bracts of

involucure more than. 0.75 mm wide

at midlength (rare)

2. Ray flowers white (frequent)

1 . Stem smooth

4. Lowest leaves narrow, 7-15 times .as long

as wide; bog plants (infrequent)

4. Lowest leaves' broader, less than 7 times

as long as wide; plants of upland habitats

5. Inflorescence very narrow; stem-leaves

5-20 mm wide (very rare)

5. Inflorescence broader; stem-leaves

broad basal leaves narrow basal leaves broad inflorescence
S. speclosa S. uilglnosa S. speclosa

Long Island September - October JW2

Botanical Society

2

3

S. puberula

S. hispida

S. bicolor

4

.... S. uliginosa

5

S. erecta

.... S. speciosa

narrow Inflorescence
S. erecta

Luge 3