Explore the Arnold Arboretum, off path and up hill, with Chris McArdle of the Appalachian Mountain Club.  The three hour walk will be followed by a bagel lunch in Jamaica Plain.  Meet at the Visitor Center on the Arborway.  Park on the street or take the T to the Forest Hills stop.  Call Chris at 617-480-3351 if the weather is bad and you’re unsure if the walk will take place.  Registration is not required for this trip.  $1 for non- AMC members, and sorry, no dogs on this outing.  For more fabulous walks in the area, log on to www.outdoors.org.