Five species in Delaware. The quotes are from Weakley's Flora.
Larger leaves wide, most over 1.5cm, with 3 or more prominent veins
"Pistillate involucres 5-7 mm high; pistillate corollas 3-4 mm high; staminate corollas 2-3.5 mm high; basal leaves tomentose on the upper surface; young stolons mostly ascending; staminate and pistillate plants equally common."
"Pistillate involucres 7-10 mm high; pistillate corollas 4-7 mm high; staminate corollas 3.5-5 mm high; basal leaves tomentose or glabrous on the upper surface; young stolons mostly decumbent; sexual and apomictic populations present."
Antennaria parlinii subsp. fallax, Hairy Big-leaf Pussytoes Native, Piedmont & coastal plain "Basal leaves tomentose on the upper surface (becoming glabrate in age); summit of young cauline stem usually glandless" (Antennaria fallax)
Antennaria parlinii subsp. parlinii, Glabrous Big-leaf Pussytoes Native, Piedmont & coastal plain "Basal leaves glabrous or nearly so on the upper surface (even when young); summit of young cauline stem usually with purple glandular hairs"
Larger leaves narrow, most under 1.5cm, with 1 prominent vein
Antennaria neglecta, Pointed Little-leaf Pussytoes Native, Piedmont & coastal plain "Middle and upper cauline leaves tipped with flags; mature basal leaves glabrous, young basal leaves pubescent, glabrescent with
age; species sexual, populations consisting of both pistillate and staminate plants."
Antennaria howellii subsp. neodioica, Blunt Little-leaf Pussytoes Native, Piedmont & coastal plain "Middle and upper cauline leaves blunt or with subulate tips (only those leaves immediately around the corymb with flags); mature
and young basal leaves pubescent; species apomictic, populations consisting of pistillate plants only."