tall goldenrod

Solidago altissima is one to two meters (40 to 80 inches) in height with fine hairs on the stem. The leaves are located along the stem, not in a rosette near the ground. One plant can produce as many as 1500 small yellow flower heads in a large conical array. The involucres of the main subspecies (S. a. subsp. altissima) are usually 3–4 millimeters, whereas those of S. a. subsp. gilvocanescens are usually 2–3 mm.

Chromosomes. Solidago altissima has a base number of nine chromosomes (x = 9). Diploid, tetraploid, and hexaploid plants with respective chromosome counts of 18, 36, and 54 have been reported among the two subspecies.

S. altissima is widespread across much of Canada, the United States, and northern Mexico. It is common in much of its range and fairly tolerant of landscapes which have been disturbed by humans. S. a. subsp. altissima is in eastern Canada except Newfoundland and Labrador, and it is in the provinces of Saskatchewan and Manitoba. In the United States, it is east of the Mississippi River except Wisconsin, Illinois, and North Carolina; all U.S. states directly on the west of the Mississippi River; and, Nebraska, Kansas, Oklahoma, Texas, Utah, Arizona, and California. In Mexico, it is in the north except on the Baja California Peninsula, Sonora, and Sinaloa. It is in all other states as far south as Oaxaca and Veracruz except Mexico, Morelos, Puebla, Tlaxcala, and Mexico City. It is native in all of the above states and provinces where it resides. It is an introduced species in East China, South Central China, Taiwan, New South Wales, Korea, and Transcaucasus. S. a. subsp. gilvocanescens (Rydb.) Semple is in western Canada and Ontario. In the United States, it is only east of the Mississippi River in Illinois and is then distributed west through the Great Plains states. In Mexico, it overlaps S. a. subsp. altissima except in the west.

Solidago altissima is self-incompatible, meaning that the pollen from one plant cannot pollinate the female flower parts of the same plant. Solidago altissima is insect pollinated and is recorded to have been visited in northern Florida by Augochloropsis metallica, Bombus bimaculatus, Bombus impatiens, Lasioglossum apopkense, Lasioglossum reticulatum, Lasioglossum weemsi/leviense, Melissodes dentiventris, Melissodes manipularis, and Pseudopanurgus solidaginus.