  We present maps at $20''$ resolution of the molecular emission around 18
evolved stars (14~asymptotic giant branch stars, one supergiant, two
proto-planetary nebulae and one planetary nebula), mostly in the $^{12}$CO(3-2)
line. Almost all molecular envelopes appear to be at least marginally resolved
at this resolution. A substantial fraction of the molecular envelopes show
clear deviations from spherical symmetry in the form of elliptical or bipolar
envelopes. This indicates that there is a need to implement non-spherical mass
loss in current scenarios of the late stages of stellar evolution, in
particular on the asymptotic giant branch.
