LANCE-LEAVED/SPOTTED EUTHAMIA (Euthamia graminifolia) - (formerly Solidago graminifolia)

This plant found growing at the edge of a ditch. It is next to a small tree/large shrub and gets morning shade and afternoon sun.

Flora of Delaware (http://www.wra.udel.edu/de-flora/) says:
--Euthamia graminifolia (L.) Nutt. var. nuttallii (Greene) W. Stone (hairy grassleaf flat-top goldenrod) - Variety nuttallii: leaf undersides, upper stems, and branches hairy
--Euthamia graminifolia (L.) Nutt. var. graminifolia (grassleaf flat-top goldenrod) - Variety graminifolia: leaf undersides, upper stems, and branches glabrate or smooth

-"Euthamia was incorrectly included in Solidago by many authors for a more than a century."
-on the basis of DNA Euthamia is not a true Goldenrod (Solidago) "in the Solidagininae sensu stricto".
-"Unfortunately, the practice of placing the grass-leaved goldenrods in Solidago continues and leads to errors in interpreting the results of ecological studies."
more at:
https://uwaterloo.ca/astereae-lab/research/goldenrods/euthamia

another example of black spots on leaves here:
http://ontariowildflowers.com/main/species.php?id=53
-The site above calls this "Grass-leaved Goldenrod (Euthamia graminifolia) (formerly Solidago graminifolia)"
-It goes on to say:
"These black spots are characteristic of Grass-leaved Goldenrod - no other Goldenrod gets these."
-black spots on leaves (last picture in series):
http://allthingsplants.com/thread/view/28646/More-for-ID/
-black spots on leaves (6th image down):
http://saratogawoodswaters.blogspot.com/2013/07/whats-new-on-ice-meadows.html

-"(...) 5-10 species (...) "These species are quite variable in appearance, the variation often influenced by environmental conditions"
-"Euthamia species are used as food plants by the larvae of some Lepidoptera species including Coleophora intermediella, which feeds exclusively on E. graminifolia."
https://en.wikipedia.org/wiki/Euthamia
https://en.wikipedia.org/wiki/Coleophora
see also:
http://www.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxon=Coleophora+intermediella&searchTax=

examples of Coleophora (casebearer) moths here:
http://bugguide.net/node/view/22007
and examples of types of cases here:
http://bugguide.net/node/view/22007/bgimage?from=0

UPDATE 2016-9-13: Finally some ID tips to differentiate between E. graminifolia and E. caroliniana - scroll down for side-by-side comparison at:
http://www.florafinder.com/Species/Euthamia_caroliniana.php
a) Narrow-leafed Goldenrod (Euthamia graminifolia)
leaves are sessile, and have resinous dots
stems, generally, have rows of hairs
b) Slender Goldentop, Slender Fragrant Goldenrod, Coastal Plain Flat-topped Goldenrod (Euthamia caroliniana)
leaves are extremely thin (2-3mm)
leaves generally bent downward or backward (deflexed), sessile, and w/ resinous dots
stems are smooth