Which weed has yellow-green leaves, upright triangular stems, and fibrous roots with tubers or nutlets, and prefers wet soil?

• A. Mouse-ear chickweed
• B. Yellow nutsedge
• C. Henbit
• D. Quack grass

Answer: (B)

Sedges stand out from grasses by a triangular (edged) stem and three-ranked, narrow leaves, a clue that points to yellow nutsedge when paired with underground storage organs. The upright, triangular stem combined with yellow-green foliage and a fibrous root system that forms tubers (nutlets) under the soil is a classic signature of yellow nutsedge, and its preference for wet, poorly drained soils fits how it typically appears in turf. This combination of stem shape, leaf arrangement, tubers, and moisture-loving habit makes it the best match for the described weed.

Mouse-ear chickweed is a broadleaf weed with small, opposite leaves and no tubers, so it doesn’t fit the sedge profile. Henbit has a square stem and distinctive purple flowers, again not matching the tuber-producing sedge. Quack grass is a true grass that spreads by rhizomes rather than forming tubers, and it lacks the three-ranked leaf arrangement and triangular stem feature.