I'm not sure, but I think he'd sent the homeless network out to look for sites with vegetation, asphalt, bricks, chocolate and chalk i.e. a brick sweet factory with vegetation in a chalky area.  I think the other pictures were of buildings, but maybe somebody sent the rhodedendron picture because it was the vegetation that stood out when they were looking at the site.  (Sherlock didn't really need to see photos at all - just know the locations).   So I don't think they were sending him pictures of plants around London, but just looking for 50s brick sweet factories with plants outside.

What's really odd is that rhodedendron grows in acid soil, rather than chalky soil.   It's a common garden escape in acid areas, but I think it would be more unusual to find it growing wild at a chalky factory site.  It's an odd choice of plant for this scene.  Unless there's more to the rhodedendron than it just ticking the "vegetation" box?

Last edited by Liberty (August 20, 2014 6:20 am)