Identifying a Thorny, Hairy-Leaved Plant in a Wet Area

Your description—thorns on leaf veins and petioles, alternate leaves with fine hairs like soybean, two main taproots with fibrous laterals, strange smell—suggests a few weedy possibilities:

• Canadian thistle (Cirsium arvense) – spiny leaves, deep roots, spreads aggressively.
• Trumpet vine (Campsis radicans) – compound leaves, aerial roots, but thorns are rare.
• Prickly sida (Sida spinosa) – small spines at leaf bases, hairy.
• Jimsonweed (Datura stramonium) – foul smell, spiny seed pods, but not thorns on leaves.

Best next steps:

1. Search "weed identification" + your state for university extension guides with photos.
2. Take clear photos: whole plant, leaf top/underside, stem thorns, root structure.
3. Email to a local extension agent or post on iNaturalist/PlantNet.
4. Wear gloves—some thorny weeds cause irritation.

Without a photo, precise ID is guesswork.