I believe the commonly used name is "Hen and Chicks", a rosette shaped succulent that reproduces miniatures of itself, looking like many off-spring. Though not native to North America, this is a hardy little plant.
"Gorgeous day. The sky is gray, full of moving clouds made invisible by the rain. Thunder keeps rumbling from the west and the light changes frequently, the sun breaking through a high layer. I couldn't be more content. I'm on the patio listening to rain falling down the gutter, pattering in the trees, titmice singing, a bluebird in the distance.... I'm comfortable in a double layer of long sleeves, no coat, no shivering. Three windows are open in the house and I have successfully made a home for my cedar chest treasure. It is a great relief to have it no longer the center piece in the living room [while I decided where to put it], to have an open floor again....Mother always called it the cedar chest. She gave it to my brother. My brother has now given it to me."
To see all three post in the series click: Brother's Plant
Wiki on Hen and Chicks
To see more patio sketching visit Seeing a Lantana.