Solidago Genus goldenrod Asteraceae

Solidago canadensis, Canada goldenrod, (Asteraceae), old-field, Falmouth, MA, 8/2015,

Solidago canadensis, Canada goldenrod, (Asteraceae), MBGargiullo. old-field, Falmouth, MA, 8/2015.

Solidago is a genus of perennial herbs with fibrous roots from very short, to elongate rhizomes sometimes forming colonies. 

Solidago canadensis, leaves w 3-vein pattern, Falmouth, MA. 8/2015

Solidago canadensis, leaves with 3-vein pattern, MBGargiulloFalmouth, MA. 8/2015

Leaves alternate, entire (not lobed or divided), margins smooth to toothed. Some species form a basal cluster of large leaves with stem leaves becoming progressively smaller upwards towards the inflorescence, Other species have no basal leaf cluster and the leaves tend to be longest at the midpoint of the stem, lower leaves die off as inflorescence develops. 

Solidago canadensis.Copyright © 2008 Kevin C. Nixon.www.plantsystematics.org (Accessed 4/2014).

Solidago canadensis.Copyright © 2008 Kevin C. Nixon.www.plantsystematics.org (Accessed 4/2014).

Flowers mostly yellow, a few with white ray flowers. Inflorescence of small heads, subtended by overlapping bracts in several rows. Each bract is green at the tip and papery at the base. The individual flowers are of two types, an outer row of larger ray flowers each having one larger petal and an inner cluster of very small disk flowers. 

Solidago virgaurea.fruit.John Crellin.floralimages.co.uk

Solidago virgaurea.fruit.John Crellin.floralimages.co.uk (Accessed3/2017)

Fruit dry, single-seeded (an achene) crowned by a cluster of elongate bristles that (presumably) aid in wind dispersal.