Want to plot line to subgroups for relation between one of the IV and the DV

Hi all,

I will try to explain my case as detailed as I'm able to...

I have measured on 11 plant species.
I want to know the determinants of the time that a pollinator needs to reach the next flower (Time; Dependent Variable).
Therefore, I have lumped the 11 plant species, ran a backwise MultipleRegression (all assumptions met) and found 5 significant Independent Variables that explain about 70%.

However, I want to know whether the different PlantSpecies react in a similar way to the separate Independent variables, to know whether there is indeed a general tendency.

How could I find out?|
I'm being told to do this with an ANCOVA.
However, how can I sort of..plot the lines that a muliple regression makes for the variables seperatly.
I know that I can have a look at the interaction terms with a GLM-->Univariate to see whether all plant species show the same type of relationship, but I don't know what to put on the Yaxis! (Covariate would be the IV of interest, fixed factor the Plant Species)

I am working in SPSS 21.
Hopefully somebody can shed light upon this case, in a easy-to-read manner.

Thanks in advance