Weed name Botanical name Harmful effects Witchweed Striga hermonthica Parasitic weed on maize, sorghum, and millet, reduces yield Speargrass Imperata cylindrica Spreads aggressively, difficult to eradicate Siam weed Chromolaena odorata Invasive, suppresses native vegetation Water hyacinth Eichhornia crassipes Blocks waterways, disrupts fishing and irrigation Itch grass Rottboellia cochinchinensis Causes skin irritation, competes with cereal crops Jimsonweed Datura stramonium Highly toxic to humans and livestock Ten common Nigerian weeds and their botanical names are Siam weed (Chromolaena odorata), spear grass (Imperata cylindrica), dayflower (Commelina benghalensis), Jimson weed (Datura stramonium), nutgrass (Cyperus rotundus), milkweed (Euphorbia heterophylla), Bahama grass (Cynodon…