We examine the blue straggler populations of 13 low-luminosity (M_V_t >~
-6) globular clusters and 2 old open clusters. These clusters test blue
straggler formation in environments intermediate between higher luminosity (and
usually higher density) clusters and the Galactic field. The anti-correlation
between the relative frequency of blue stragglers (F_BSS = N_BSS / N_HB) and
cluster luminosity continues to the lowest luminosity clusters, which have
frequencies meeting or exceeding that of field stars. In addition we find that
the anti-correlation between straggler frequency and central density disappears
for clusters with density less than about 300 L_V,sun pc^-3, although this
appears to be an artifact of the correlation between cluster luminosity and
central density. We argue on observational (wide, eccentric binaries containing
blue stragglers in M67, and the existence of very bright stragglers in most of
the clusters in our sample) and theoretical grounds that stellar collisions
still produce a significant fraction of the blue stragglers in low luminosity
star clusters due to the long-term survival of wide binaries.Comment: 13 pages, 3 figures, accepted to ApJ Letter