Sperm in flowering plants are structurally unique plant cells with specialized features including microtubule bundles, condensed chromatin, small cytoplasmic volume, and absence of cell walls.
Flowering plant sperm differ from sperm of non-seed plants and of most animals in their lack of flagella.
Found in:
Motile sperms are seen in bryophytes, and pteridophytes, and some of the gymnosperms like ginkgo, and cycads possess motile male gametes.
Cycas contains the largest motile male gamete in Kingdom Plantae.