02/10/2024 maybe also Lomatium??

This seed cover looks a lot like the carrot leaf Lomatium and it does seem to be their sprouting time. And I’m pretty sure I seeded some here in backyard concrete blocks. the fuzzy seedlings nearby are Heterotheca subaxillaris (pretty sure) and the little succulents are Sedum pulchellum.
A second suspect, sans seed cover, with two long skinny seed leaves. That wrinkly thing is my gloved finger tip.

01/16/2024 sneaky

The plant window is backlit brightly. You can see houseplants fully visible on the top shelf and the shapes of decorations and pots on the second shelf. On the bottom cat level, Shackleton’s face is in profile as he faces east to the morning sun.
I think Shackleton thinks he is hidden as usual in the plant window. He seemed very surprised when I growled his name sternly as he tried to climb to the forbidden next shelf!! I left a thermometer in there and on the cold nights it was in the 40s F. I guess the sun is very tempting and the fleece blanket keeps the metal floor from being cold and wet as frost melts from the glass.