Vela heavy ion and IMP solar wind data are used to identify the coronal origins of the interstream, low-speed solar wind as well as to understand the causes of the long-term trends in solar wind densities and electron temperatures observed at 1 AU. Several lines of evidence suggest a strong association between interstream flows and the extensions of the near equatorial band of coronal streamers into interplanetary space. This evidence includes (1) the moderate to high plasma density and oxygen freezing in temperatures measured at 1 AU which match similar conditions within coronal streamers close to the sun, (2) the strong association between sector boundaries and/or general field polarity reversals with both interstream flows at 1 AU and the photospheric footpoints of coronal streamers, and (3) the correlation between the long-term trend in coronal morphology and the long-term variation in the occurrence frequency of noncompressive density enhancements (NCDE's) which occur often within interstream flows. Our study further indicates that high electron temperatures at 1 AU result from a lower temperature gradient in the corona rather than an overall higher coronal temperature. Such conditions hold preferentially at the edge of NCDE's at 1 AU and hence by inference, the edges of coronal streamers near the sun. The observed flattening of the streamer belt about the solar equator near solar minimum, then led to a concurrent preferential sampling of streamer associated solar wind at 1 AU and hence a higher average density and electron temperature.