Fig. 2
From: Sporogenesis, gametophyte development and embryogenesis in Glehnia littoralis
Anther development of G. littoralis. a Differentiation of anther primordial. b Differentiation of archesporial cells. c The complete anther wall. d-j Meiosis of microspore mother cells. k, l The tetrad of microspores. m, n microspores released from tetrad. o, p Microspore growth and development. q The early mononuclear stage. r The late mononuclear stage. s, t Dikaryophase. u, v Matured pollen grains. w, x Anthers mature and dehiscent. Ep: epidermis, et: endothecium, ml: middle layer, ta: tapetum, mmc: microspore mother cells, dy: dyad, ca: callus, mt: microspore tetrads, m: microspore, vn: vegetative nucleus, sp.: sperm, mp: mononuclear pollen, bp: binuclear pollen, tp: trinuclear pollen. Scale bar = 20 μm in a-v; scale bar = 50 μm in w-x