The private pilot of a predominately black and orange colored, tailwheel-equipped airplane (black airplane) reported that he was taxiing in the grass next to the turf runway 25 for departure. The taxi route required him to cross another converging turf runway 23. During the taxi, he did not make any radio calls on the airport common traffic advisory frequency (CTAF) announcing that he was taxiing or crossing runway 23. The commercial pilot of a predominately red and white colored, tailwheel-equipped airplane (red airplane) that was based at the airport stated that he was departing runway 23, which was primarily used for glider operations but also was routinely used by powered airplanes when available based on runway conditions. He scanned ahead on runway 23 and after observing there was no conflicting traffic and not hearing any announcements from other aircraft, he broadcast his intent to depart from runway 23 on the CTAF. That transmission was heard by the pilot of the black airplane but at the time it did not register to him that the red airplane was departing from a converging runway, adding that he looked along runway 25 and expected to see the red airplane departing but he did not. The pilot of the red airplane reported that just after lifting off, the right wing of his airplane and the right wing of the black airplane collided; he never saw the other airplane. Following the collision, the red airplane impacted the ground and rolled onto its right side. The pilot of the black airplane, who was taxiing slowly, reported he heard a loud engine followed immediately by the sight of something hitting his right wings. Both airplanes sustained substantial damage to their wings during the collision. The pilots of both airplanes reported no preimpact mechanical malfunctions or failures with their airplanes that would have precluded normal operation. According to the airport manager, the runway utilized by the pilot of the red airplane was specified in the airport facility directory to be for gliders only, though that was not strictly enforced.