Globe Flatsedge, Round Sedge, Hedgehog Globerush
Cyperus echinatus (L.) Wood.
Cyperaceae (Sedge Family)
▲ ▼ mature, flowering plants
▲ ▼ globe-like inflorescences
▲ underside of stem up to inflorescences
▲ root base-- tends to form short, knotted rhizomes
Globe Flatsedge -- usually not much of a weed problem, but people may be curious about it when it is growing in their lawn.
(No additional information, yet.)