How many end devices can a coordinator handle.

i am designing a WSN where i have 30 xbee series1 as end devices,used for direct io. basically a DAQ system.
My question is can 1 coordinator handle all 30 end point or i need routers.
please note all end points are in close proximity to coordinator so range is not a problem.
also i will me manually polling for data from each end point so congestion should not be an i correct?
i want this system to be scalable…ie. 30 50 …so on end points …thus i want to knoe the maximum no of end points a coordinator can handle.
Network topology is a star.i dont need a mesh type network

The 802.15.4 firmware does not have a limit to the total number of end points a coordinator can support. Especially when used in a Polling method.