A detailed collection of weeds in ten tehsils of Chambal Commanded Area, Have been listed with a statistical synopsis in the present paper. Leguminaceae, Compositeae and Gramineae make more than 1/3 of the flora, these coupled with Euphorbiaceae and Amaranthaceae cover about fifty per cent of the flora. The remaining flora is composed of thirtyeight families. Except Gramineae monocots are poorly developed. Euphorbia, Indigofera, Corchorous have more than four species. Other genera are poorly represented.

Digera, Psoralia, Celosia, Alysicarpus, Rungia, Justicia and Euphorbia are very common in kharif season. Obnoxious creeping weeds of this season are Cynotis, Merremia, Trianthema, Convolvulus and Ipomea spp. In Rabi season Chenopodium, Sonchus, T'rigonella, Medicago, and some species of Euphorbia are very common in this area. The only parasites found in the crops in this area are Striga euphr asioides and Cuscuta spp.

Certain crop weed associations need special mention because ot their severe competition with crops and further studies are required regarding the relative losses and their extent due to such competition. Wheat crop suffers

due to Chenopodium album, C. murale and Convolvulus arvensis, Paddy due to Ammania baccii era, Rottela denscfiora, Cyperus aristatus and Caesulia axillaris, In kharif sorghum, pluses, Til, Groundnut, in general sustain a strong competition with Digera muricata, Ru.ngia ,epens, Celosia argente a, Echinochola colonurn, Psoralea corvlii olia. Merremia emarfinl.1ta, Cyperus rotundus, d usticia quinqueangularis, Vernon; a cony zoides, Vicoa indica etc. These weeds are very common and under favourable conditions of good rainfall even total crop losses in some fields do occur due to these competitions. Selective association of Cuscuta in Lucerne. Striga in Jowar and Ipomea in sunhemp are also worth recording.