Question on xyplot

I recently started using R, so I'm not really experienced with it. My
question is on adjusting xyplots to get lty lines instead of coloured
lines. 

My datasets looks about this:
year    area    species        x
1998      1         x1          0.005
1998      2         x2          0.006
etc. 

year is factor from 1967 to 2013
area is factor from 1 to 10
species if factor, with 7 species

the following code works:
xyplot(x~Year|Area, data=prob2, groups=Species, type="l", auto.key=TRUE)

but then I have all coloured lines. 

when I insert lty=0:7, col="black", it works, however my legend stays with
different colours 

What do I have to insert in my code to get black lty lines also in the
legend? 

Thanks in advance!