[P/Fe] vs. [Fe/H] for stars in our sample (shown in red) with their respective stellar population represented by different symbols (thin disk, circle, thick disk, inverted triangle; and halo, s-rich, diamond). Arcturus, for which phosphorus was determined from the higher resolution atlas spectrum (Hinkle et al. 1995), is indicated by the black star symbol. Phosphorus abundance determinations (all scaled to the solar abundance used in this work: A(P)_⊙ = 5.36 and A(Fe)_⊙ = 7.45) from multiple literature sources are also plotted in gray (giants in black) and represented by different symbols. With a dashed line, we show the chemical evolution trend in Cescutti et al. (2012) resulting from the core collapse SN (type II) of massive stars with the phosphorus yields from Kobayashi et al. (2006) arbitrarily increased by a factor of 2.75.