There is a prolific "weed" in my backyard, and it is Mossy Stonecrop. I've read it occurs in sandy soils with low fertility. It's growing in and around the raised wooden garden beds, especially in the strawberry patch. It can reproduce from creeping stems and stem fragments, as well as by seed. That means if I wanted to weed it out, any small fragment left in the soil could grow into a new plant.
What is a weed? An unwanted plant, a nuisance...perhaps. My experience organic farming and reading gardening books has challenged the common conception of weeds I once held. Such plants can have many benefits.
All weeds tell us something about the soil they are growing in. Plants don't grow by luck, certain conditions foster them. Weeds (and all plants) have different capacities to draw specific nutrients up from various levels of the soil. Many "weeds" are edible. If slashed or pulled they can be used as mulch, and can also form a living mulch around plants.
While I won't allow weeds to strangle out plants I'm intentionally growing for food, I do want to learn from them more this growing season. Perhaps I need to add more organic matter to my soil, since Mossy Stonecrop thrives in soils with low fertility. I don't mind it's presence bordering the outside of the bed, and creeping inbetween the patio stones. I like succulents and it produces a yellow flower in the summer. I did pull a lot of it out of the strawberry patch. I will watch to see how it grows over the season.