Polarised light micrograph of the microsporangium of Selaginella. Selaginella, also known as spikemoss or lesser clubmoss is a primitive spore forming plant allied to ferns. Microspores, which will become the male gametophyte, develop within the microsporangium (the circular area in the centre). Here the microsporangium has split to release some of its spores. The leaf-like structure is called a microsporophyll. Magnification: x6 at 10cm wide.