In both D. stramonium and D. metel the plants are glabrous, hairy in D. inoxia
The deciding difference between D. metel and D. stramonium is that mature fruit of D. metel is drooping, covered with short blunt tubercles barely exceeding 3 mm; in D. stramonium mature fruit is erect covered with long spines up to 5 mm long.
In addition the following may help. Plants of D. metel are generally taller less branched and erect often reaching 1.5 m and tend to have purplish stem, in D. stramonium plants are shorter, more branched and spreading, stems not purplish.
The leaves of D. stramonium are generally parted, whereas they are not parted in D. metel
Dr. Gurcharan Singh
Retired Associate Professor
SGTB Khalsa College, University of Delhi, Delhi-110007
Res: 932 Anand Kunj, Vikas Puri, New Delhi-110018.
Phone: 011-25518297 Mob: 9810359089http://people.du.ac.in/~singhg45/