Which weed has triangular stems, three-ranked leaves from near the ground, and seed heads that resemble burs?

Which weed has triangular stems, three-ranked leaves from near the ground, and seed heads that resemble burs?

• A. Nutsedge, Yellow
• B. Puncturevine
• C. Plantain, Broadleaf
• D. Poison Ivy

Answer: (A)

The key idea is recognizing a weed by its distinctive plant structure. A triangular stem and leaves that come in three ranks around the stem near the base point to a sedge, not a grass or broadleaf plant. Yellow nutsedge fits this pattern: the stem is triangular in cross-section, the leaves arise in three horizontal planes (three-ranked) around the stem close to the ground, and the seed heads form a cluster of small spikelets that can look like burrs as they mature. This combination—triangular stem, three-ranked leaf arrangement, and burr-like seed head—is characteristic of nutsedge, making it the best match for the description. The other plants don’t share this combination: puncturevine has burrs but its leaves are pinnate and its stems aren’t triangular; broadleaf plantain forms a low rosette of broad leaves without three-ranked leaf arrangement or triangular stems; poison ivy shows three leaflets on a leaf stem, not three-ranked leaves around a stem.

The key idea is recognizing a weed by its distinctive plant structure. A triangular stem and leaves that come in three ranks around the stem near the base point to a sedge, not a grass or broadleaf plant. Yellow nutsedge fits this pattern: the stem is triangular in cross-section, the leaves arise in three horizontal planes (three-ranked) around the stem close to the ground, and the seed heads form a cluster of small spikelets that can look like burrs as they mature. This combination—triangular stem, three-ranked leaf arrangement, and burr-like seed head—is characteristic of nutsedge, making it the best match for the description. The other plants don’t share this combination: puncturevine has burrs but its leaves are pinnate and its stems aren’t triangular; broadleaf plantain forms a low rosette of broad leaves without three-ranked leaf arrangement or triangular stems; poison ivy shows three leaflets on a leaf stem, not three-ranked leaves around a stem.