Asteraceae : Solidago canadensis

Solidago canadensis is a perennial, herbaceous plant with a fibrous root system and well-developed creeping rhizomes, often forming dense colonies. Plants typically reach 0.5–2 meters in height. The stems are erect, slender, unbranched below the inflorescence, and covered with short, fine hairs, especially toward the upper portions. Leaves are alternate, simple, 3-nerved, mostly lance-elliptic, 6–15 cm long and 1–3 cm wide, broadest near the middle, and tapering toward the base and to a sharp point at the tip. Leaves are sessile or have very short petioles and the margins are mostly sharply toothed except near the leaf base (leaves may be toothless or nearly so just below the flower clusters). Upper leaf surfaces are medium to dark green and rough-textured, while lower surfaces are lighter green and softly pubescent along the veins and occasionally over much of the surface. Flowering occurs from August through October, with the inflorescence forming a large, plume-like, branching panicle up to 40 cm long, composed of numerous small yellow flower heads. Each involucre is bell-shaped, 2–3 mm long, with several overlapping, greenish to yellowish, lanceolate phyllaries. Each head contains 7–15 yellow ray florets (about 2–4 mm long, 0.5–1 mm wide) and 3–10 yellow disc florets. Stamens are five per disc floret, with yellow anthers about 1.5 mm long, forming a tube around the style; the prominent style is 2–3 mm long with a bifid stigma. The fruit is a small, dry, ribbed cypsela (achene), 1–2 mm long, grayish brown, maturing in late fall; each is topped by a white to pale brown pappus of fine bristles, 1.8 to 2.2 mm long. Canada goldenrod is native to South Dakota and is common throughout the state, found in prairies, fields, roadsides, and other disturbed or open habitats with full sun and well-drained or moderately moist soils. Solidago canadensis and Solidago altissima are difficult to differentiate. S. altissima has longer pappus hairs and thicker, firmer leaves that are minutely toothed or mostly toothed in the tip half where S. canadensis leaves are thinner, laxer, mostly toothed nearly to the leaf base, and is generally less hairy throughout.