Yellow Woodsorrel (Oxalis stricta)
also known as: Ceratoxalis coloradensis, Oxalis europaea, Oxalis prostrata, Oxalis rupestris, Xanthoxalis florida, Shamrock, Sleeping Beauty, Sour Trefoil, Sour Grass, Common Yellow Oxalis etc.
Division - Magnoliophyta
Class - Magnoliopsida
Subclass - Rosidae
Order - Geraniales
Family - Oxalidaceae
Genus - Oxalis
I was always told this was a clover, but it isn't. It has a completely different flower than the clovers, though they both belong to the Magnoliopsida class.
As far as common garden weeds go, this is a good one. It pulls out easily if you want to get rid of it, but it is a nice looking plant with nice little yellow flowers.
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