Table 2.

Exotic weeds encountered in six Hmong villages in Nan province, Thailand.

Scientific Name (Varangrat Nguanchoo Voucher Number)	Origin	Global Distribution	Habit	Habitat	Dispersed by
Amaranthus spinosus L. (625)	America	Pantropical, widespread in South Africa	Annual	Cultivated beds, open wastelands, margin of streams	Water
Bidens biternata (Lour.) Merr. & Sherff (645)	America	Tropical and subtropical Africa, Asia and Australia.	Annual	Orchards, wastelands, re-vegetation areas, forest gaps and margins	Vehicles, water, agricultural produce
Celosia argentea L. (652, 923)	Africa	Pantropical, spreading early throughout Asia and Malesia	Annual	Plantations, pastures, open wastelands, and sometime ornamental plants	Wind, water
Chromolaena odorata (L.) R.M.King & H.Rob. (624, 970)	America	Tropical and subtropical regions	Perennial	Plantations, rice paddies, pastures, crops, roadsides, wastelands, forest margins, and neglected fields	Wind, water, vehicles, machinery, in clothing, animals, agricultural produce
Crassocephalum crepidioides (Benth.) S. Moore. (622)	Africa	Tropical regions	Annual	Coffee and tea plantations, abandoned farmland, wastelands, backyard gardens, shifting cultivation sites	Wind, water
Mimosa pudica L. (602, 745, 796)	America	Tropical regions	Perennial	Plantation crops, pastures, lawns, wastelands, along roadsides.	Animal fur, feathers or on clothing
Passiflora foetida L. (975)	America	Tropical regions including south-eastern Asia, and many Pacific islands	Annual	Plantation crops, roadsides, wastelands, watercourses, closed forests, open woodlands, and coastal.	Birds and bats with the eaten ripe fruit
Scoparia dulcis L. (608, 741, 777)	America	Tropical and subtropical regions	Perennial	Wastelands	Cattle and buffaloes