Bright green lawn weeds

[Jaylunk]

Can someone help me identify this annoying “sprout” like lime green grass or grass weed that spreads across my lawn only in the hot weather and can be pulled up with ease? I fertilizer regularly and have an otherwise healthy lawn until about July (in Connecticut).

[applestar]

Do these grass stems grow in form of a triangle? if so, probably Yellow Nutsedge. They have seedheads that I always think of as “sparklers” (hand held firecrackers) — we used to pretend with them as children. In addition to the seeds, they make underground “nut” bulbs? corms? So when you pull them up, the roots come up but the “nuts” stay in the ground and grow again.