and the seed balls typically two per stem (one in P. occidentalis, 3-6 in P. orientalis). The hybrid is fertile, and seedlings are occasionally found near mature trees.

Controlled reciprocal pollinations between P. occidentalis and P. orientalis resulted in good yields of germinable seed and true hybrid seedlings. Crosses of both species, as females, with P. racemosa and P. wrightii produced extremely low yields of germinable seed, but true hybrids were obtained from all interspecific combinations. Apomixis