expansion of poly interaction

[Kimberly Van Niel <Kimberly.VanNiel@anu.edu.au>]

Hello,
I am attempting to expand an interaction between a factorial data
variable and a poly of a continuous variables so I can retrieve the
coefficients.
My original coding is: 

Biomass ~
Year:poly(B7,3)

which I assume expands to: 

Biomass ~ Year:I(B7) + Year:I(B7^2) + Year:I(B7^3)

Is this correct?

Thanks for all your help,
Kimberly Van Niel
PhD candidate
The Australian National University