Goldenrods are members of the Composite Family, so by no means do their blossoms have the same structure as our Standard Blossom. If you run across a goldenrod, try to find the following parts of the actual goldenrod flower.
In the above photo you can see that the flowering yellow top -- the inflorescence -- of each goldenrod plant consists of numerous arching, fingerlike structures. On our Blossom Arrangement Page we see that this kind of inflorescence is known as a panicle. The fingerlike structures are branches of the goldenrod's panicle. At the left you see one of those branches magnified several times. Each of those cylindrical things with a fuzzy top is a head consisting of several flowers.
At the right you see a much-magnified head. If you don't know about ray and disk flowers, check out our Composite Family page. The outwardly flaring items that in other blossoms we might call petals are actually ray flowers. Inside the head are visible several disk flowers. A couple of the disk flowers have anthers rising above them. This whole collection of ray and disk flowers is held together in a slender, greenish-yellow, cuplike structure known as the involucre. If you were holding the head in your hand, you could separate the longish, flattish, tongue-like involucral bracts from one another.
At the left you see a much-much magnified disk flower, with a less-magnified ray flower shown in the yellow-framed inset at the lower right in the picture. Now things are beginning to look a little more like our Standard Blossom, for the corolla tube has five petal-like lobes. The entire disk flower measures only about 3/16ths of an inch long (4 mm).
The pappus consists of stiff bristles atop the inferior ovary (as explained on our Standard Blossom page). Later both of these items will enlarge, while other flower parts will wither and fall off. The inferior ovary will become a special kind of hard, dry fruit called an achene, and the pappus will develop into a kind of "parachute" that will help the achene travel to a new location on the wind.