Marijuana Farmer was originally produced in 1961 by Esoteric. In 1967, Bob Wendell modified the design slightly and used intense colors to hand-print these silk-screened posters. Only a few hundred were produced.
(click on images to enlarge)

Marijuana Farmer Artists: Roland Crump & Robert Wendell
White with Blue
Serigraph, 20" x 12 1/2" (designed in 1961/modified in 1967)
Published by Esoteric/Blue Angel/Wendell  

Also available in red
Heroin Airlines was printed on white stock and reproduced in small numbers in 1961. Then in 1967 it was modified and hand-printed by Bob Wendell in very limited quantities as a silkscreen poster.
Heroin Airlines Artist: Bob Wendell
Orange with Blue
Lithograph, 20" x 13" (designed in 1961/modified in 1967)
Published by the Esoteric/Gawd Awful   
This is classic psychedelic artist Rick Griffin's original design. Original and undistributed from 1967. Perfect condition!
Canablis Artist:Rick Griffin
Blue with Orange/Red
Lithograph, 20" x 13" (1967)
Distributed by Berkeley Bonaparte  
Inspired by Esoteric's "opium" design of 1961, this poster was designed by Bob Wendell using intense psychedelic colors in 1967. A very rare poster sold only through head shops in 1967 and 1968.
Try Opium   Artist: Robert Wendell
Orange with Blue
Lithograph, 20" x 13" (1967)
Published by Esoteric/Gawd Awful  
Smoke Opium  Artist: Roland Crump
White with Black
Serigraph, 20 1/2" x 15" (1961)
Published by the Esoteric Poster Company   
Smoke Marijuana  Artist: Robert Wendell
Yellow with Green
Serigraph, 8 1/4" x 6" (1961)
Published by the Esoteric Poster Company   
Take the Flyer on the LSD  Artist: Robert Wendell
Red, White and Blue
Lithograph, 20" x 13" (1967)
Published by the Esoteric Poster Company   
Cocaine Candy  Artist: Roland Crump
White with Black
Serigraph, 20 1/2" x 15" (1961)
Published by Esoteric Poster Company