The Goldenrods comprise a large genus of more than one hundred and twenty-five species, all but a few native of North America. In New York there are found about thirty species of this group. They are perennial, erect herbs, often simple or with few branches; alternate leaves which are either toothed or entire, and numerous small heads of both tubular and ray flowers, or rarely whitish flowers, in terminal or axillary panicles, thyrsi, or cymose-corymbose or capitate clusters. The involucre of each head is oblong or narrowly bell-shaped and composed of bracts overlapping each other in several series, the outer ones successively shorter. Disk flowers usually all perfect, that is, with both stamens and pistils, their corollas tubular and five-lobed; ray flowers arranged in one series and pistillate. Achenes in fruit smooth or angled and usually ribbed. Pappus of numerous, hairlike, rough or nearly smooth, white or slightly tawny bristles.

The amateur botanist may experience some difficulty in the use of the following key to the New York species of Goldenrod, since it is practically impossible to indicate the distinguishing characters without the use of technical terms.

Ray flowers more numerous than the disk flowers; heads corymbose-paniculate (Flat-topped Goldenrods)

Leaves distinctly three-ribbed; heads twenty to thirty-flowered....................

Euthamia graminifolia Leaves one-ribbed; involucre campanulate, one-sixth of an inch high or less.........

Euthamia tenuifolia Ray flowers not more numerous than the disk flowers (True Goldenrods)

Tips of the involucral bracts, or some of them spreading or recurved; leaves smooth. .

Solidago squarrosa Tips of the involucral bracts all erect and appressed

Heads in axillary clusters or also in a terminal spikelike sometimes branched thyrsus Heads one-sixth to one-fourth of an inch high, chiefly in axillary clusters; achenes pubescent

Stem and branches terete; leaves lanceolate to oblong................

Solidago caesia Stem and branches grooved or angled; leaves broadly oval, contracted into margined petioles............'....Solidago flexicaulis

Heads one-sixth to one-fourth of an inch high, chiefly in a terminal spikelike thyrsus; achenes smooth or nearly so Rays white; stem pubescent.................Solidago bicolor

Rays yellow; stem densely pubescent.........Solidago hispida

Ravs yellow; stem smooth or sparingly pubescent; leaves thick, dentate or the upper entire, not acuminate...........Solidago erecta

Heads about one-half of an inch high; bracts elongated, pointed; leaves ovate................................Solidago macrophylla

Heads in a terminal, simple or branched thyrsus, not at all or scarcely secund on its branches; plant glabrous Low alpine species, 10 inches high or usually less; heads with thirty flowers or more.....................................Solidago cutleri

Taller species, not arctic-alpine

Bracts of the involucre linear-subulate, very acute; stem puberulent. . .

Solidago puberula

Bracts of the involucre blunt or slightly pointed; stem glabrous of sparingly pubescent above Bog species; inflorescence wandlike. ...Solidago uliginosa Upland species; inflorescence various Heads very short-peduncled

Leaves thick, firm in texture, little toothed or entire; very tall with oval or broadly ovate lower leaves which are serrate....................Solidago speciosa

Leaves thin in texture, at least the lower ones serrate; low species.......................Solidago randii

Heads distinctly slender peduncled; basal leaves narrowly oblanceolate, one-third of an inch wide or less.............

Solidago racemosa Heads in a terminal, usually large panicle, secund on its spreading or recurved branches

Maritime plants with thick fleshy entire leaves..........................

Solidago sempervirens Not maritime; leaves not fleshy

Leaves all entire, thin and glabrous.............Solidago odora

Leaves, at least the lower ones, more or less toothed or serrate Leaves pinnately-veined, not triple-nerved

Stems densely pubescent; leaves more or less so and rugose-veiny beneath, sharply serrate......Solidago rugosa

Stems glabrous, or merely puberulent above

Leaves very rough on the upper surface, serrulate........

Solidago patula Leaves smooth, or minutely roughened on the upper surface Racemes few, widely divergent, very slender, lower leaves oblong, coarsely serrate and thin...........

Solidago ulmifolia

Racemes numerous, spreading, recurved or ascending

Leaves all oblong or oblong-lanceolate and sessile...............Solidago elliotii

Leaves, at least the lower ones petioled, lanceolate or ovate-lanceolate

Leaves firm, ovate-lanceolate or oblong-lanceolate; heads about one-sixth of an inch high; racemes short; rays several.... Solidago neglecta Leaves firm, narrowly lanceolate; heads about one-sixth of an inch high; racemes few, short, rays one to five............

Solidago uniligulata

Leaves firm, lanceolate or oval-lanceolate; heads one-sixth to one-eighth of an inch high; racemes numerous, slender.........

Solidago juncea Leaves thin, the lower broadly ovate, short-acuminate; heads one-sixth to one-fourth of an inch high; racemes numerous......

Solidago arguta Leaves triple-nerved, that is, with a pair of lateral veins much stronger than the others Heads small, the involucre only 11/4 lines high or less; stem glabrotis or pubescent........Solidago canadensis

Heads larger, the involucre one-sixth to one-fourth of an inch high

Stems glabrous; leaves and involucral bracts thin........

Solidago serotina Stem pubescent or scabrous

Leaves lanceolate, sharply serrate or entire, rough above................Solidago altissima

Leaves oblanceolate, spatulate, oblong or ovate; minutely rough-pubescent, grayish; lower leaves oblanceolate; crenate; heads one-sixth to one-fourth of an inch high

Solidago nemoralis Heads in a terminal, corymbiform, sometimes thyrsoid cyme, forming a flat-topped inflorescence, (genus Oligoneuron Small)

Leaves ovate, oblong, or oval, mostly rough on both sides ..............

Solidago rigida

Leaves lanceolate, linear, oblong or oblanceolate, glabrous or nearly so

Lower leaves oblong-lanceolate, serrulate; plant 3 to 4 feet tall........

Solidago ohioensis Lower and upper leaves all lanceolate or linear, entire, the basal leaves

4 to 5 inches long; plant 5 to 24 inches high......................

Solidago houghtonii

In addition, there has recently been described from Long Island an additional species (Solidago aestivalis Bicknell), said to be like S. arguta Miller, but essentially smooth. The description suggests a form of S. patula Muhlenberg.