I want to trim info from the beginning and end of data

Example1:
2 Abutilon Kentish Belle 2 litre

return: Abutilon Kentish Belle

Example2:
2 Acer plat. Crimson King 10 litre 1/2 Stan

return: Acer plat. Crimson King

Example3:
2 Azalea mollis (copper) 4 litre

return: Azalea mollis (copper)

As you can see there will be different requirements for the same formula to
accout of.
Any help warmly welcomed.

Pat