In which phylum do we see plants with lignin, vascular system but no seeds?

Answer is the phylum is Pteridophyta. Pteridophytes are first land plants, examples ferns, Lycopodium, Selaginella. Members have liginified cells and developed conducting tissues called vascular system to conduct water and synthesized food. They reproduce through spores, seeds do not develop in pteridophytes.

segmentation=endoskeleton=backbone=coelom=tissues

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.