Solidago rugosa Mill.

Rough-Leaved Goldenrod

© DETenaglia

Family - Asteraceae/Astereae

Habit - Perennial forb with long, branched rhizomes, often with a thickened base.

Stems - To 1.5m tall, erect, herbaceous, from slightly thickened roots and horizontal rhizomes, terete, densely pubescent (at least in the middle and upper portions), retrorse pubescent near the base, simple except in the inflorescence.

	Base and rhizomes of plant.
© DETenaglia

	Lower stem.
© DETenaglia

	Upper stem.
© DETenaglia

Leaves - Basal rosette absent at anthesis. Cauline leaves reduced from the base of the plant to the apex, alternate, sessile. Blades lanceolate near the bottom of the plant becoming elliptic to ovate neat the apex, to +7cm long, +/-2cm broad, shallow crenate-serrate along the entire margin. Veins very impressed above giving the leaf a rugose appearance, veins expressed below. Blades scabrous adaxially and dull green, pubescent on the veins abaxially and lighter than the adaxial side.

© DETenaglia

Inflorescence - Pyramidal, paniculate arrangement of flowering branches and flower heads. Inflorescence branches pubescent, to +10cm long. Each flower head with a minute bract at the base of its peduncle. Bracts green, subulate, 1mm long. Flower heads secund on inflorescence branches. Peduncles 1-3mm long, pubescent.

Involucre - 2-4mm high (long), -2mm in diameter, light green. Phyllaries imbricate, glabrous, obtuse at the apex. Longest phyllaries to 2-3mm long, -1mm broad.

© DETenaglia

Ray flowers - 5-9 per head, pistillate. Ligule elliptic, notched at the apex, glabrous, yellow, 2mm long, 1mm broad. Corolla tube +/-2mm long, greenish-translucent, glabrous, thin. Stigmas exserted, yellowish to reddish, +?-1mm long. Pappus of capillary bristles, white, antrorse barbellate, 2-3mm long, uniseriate.

Disk flowers - +/-5 per head, perfect. Corolla 5-lobed, 2-3mm long, expanded and yellow in the apical half, contracted and greenish in the basal half, glabrous. Lobes acute, spreading, 1mm long, .6mm broad, subulate. Stamens 5, adnate at the base of the expanded portion of the corolla tube. Filaments wanting. Anthers yellow, connate around the style, partially exserted, 1.5mm long. Stigmas lanceolate, yellow, -1mm long, mostly remaining erect, exserted beyond the anthers. Pappus as ray flowers. Achene retrorse pubescent in flower. Mature achenes not seen.

© DETenaglia

Flowering - August - October.

Habitat - Wet ground of swales, swampy meadows and thickets, borders of spring branches, borders of streams, wet prairies, occasional on dry sandy knolls and ledges.

Origin - Native to the U.S.

Lookalikes - Other species of Solidago.

Other info. - This goldenrod species can be found in the eastern portion and also the southwestern corner of Missouri. It occurs throughout most of the eastern U.S. and also ranges into Canada. The plant can be identified by its habitat, rhizomes, pubescent stems, and sessile, rugose leaves.

Steyermark subdivided the species into three varieties based on stem pubescence and inflorescence shape. Yatskievych recognized two subspecies based on leaf characters and number of ray florets. Other authors have recognized varieties of subspecies. Many of these are difficult to distinguish. The complex is in need of clarification.

Photographs taken at Fort Benning, GA., 10-10-05.