One of the garden favorites that have become occasional urban weeds, Moss Rose can pop up just about anywhere. This one was growing out of the asphalt along the curb on a back street in Brookline. We can see its family resemblance to the much more common Purslane (Portulaca oleracea): both are succulent plants, mostly flopped along the ground (“prostrate,” as the botanists would say), with five-petaled flowers. But the flowers of P. grandiflora are, as the name implies, very large in proportion to the rest of the plant, and they come in many colors; volunteers are most commonly electric magenta like this one. The leaves of P. grandiflora are more linear, as opposed to the elliptical leaves of P. oleracea.