Growing quite large in one of my wildflower patches. A closer picture showing the newly-opening bloom, and a view from further back showing the size.

My first thought was Sunflower (Helianthus) but then I got to thinking it looks a lot like Rudbeckia. R. hirta is a Maryland native and I found this article saying that R. hirta var. pulcherrima is the one found all over the state: https://extension.umd.edu/hgic...
Blackeyed Susan (Rudbeckia hirta var. pulcherrima)
Black Eyed Susan (Rudbeckia hirta)

Or possibly Rudbeckia fulgida? Our database info states to 24 inches in height but other places say 36" and Wikipedia says to 47 inches tall.
Black-Eyed Susan (Rudbeckia fulgida)
http://www.marylandbiodiversit...
http://www.missouribotanicalga...
https://en.wikipedia.org/wiki/...

thanks, Lin! I was wondering about Rudbeckia as well!! I was also wondering about maybe Ratibida pinnata? (from the wildflower seed mixes I sowed...) I need to get some close up shots of the leaves. Both Rudbeckia and R. pinnata were in the mixes, so maybe they are both possibilities?

Okay, went trudging through my backyard in my bathrobe, much to my neighbors' delight I'm sure! But got a couple good more close-up photos:



I do have several varieties of Rudbeckia fulgida in my yard, but most of them have wider leaves than this one has-- the leaves on this one are more narrow. I do have a Rudbeckia hirta that has more narrow leaves. Here is my R hirta, just about ready to bloom:


But the wildflower seed mix did contain the Ratibida pinnata.
http://www.discoverlife.org/20...

Anyone have any thoughts on which it might be?

Rudbeckia was just a guess on my part ... hopefully someone more knowledgeable about identifying plants will pop in with suggestions soon! I'm not familiar with Ratibida but I guess it could be Gray-Headed Coneflower (Ratibida pinnata)

thanks, Lin.
I was just looking at the photos and noticing that the R hirta stems are hairy, and the Ratibida stems do not appear to be so.
I think you are right and it is R hirta!!