Pollen germination of common juniper in vitro (A–D) and in vivo (E and F): A – formation of hydrophilic capsules and shedding of exine of pollen grain (stage 1); B – two-cellular microgametophyte (stage 2); C – pollen tube on stage 3 (it is visible shedding exine, tip of a pollen tube leaves from hydrophilic capsules, without breaking through its wall); D – generated pollen tube, hydrophilic capsule has remained; E – pollen grain on a surface of a pollen pillow of nucellus (exine it was opened with two equal valves, is visible not germinated microspore); F – distal tip of a pollen tube shortly before fertilization (later 13 months after pollination, remained hydrophilic capsule is visible). ex – exine; hc – hydrophilic capsule; msp – microspore; gcn – nucleus of generative cell; tcn – nucleus of tube cell; pt – pollen tube; npp – pollen pillow of nucellus; pg – pollen grain; sc – seed coat

  Part of: Surso M (2018) Pollination and pollen germination in common juniper (Juniperus communis: Cupressaceae). Arctic Environmental Research 18(4): 162-174. https://doi.org/10.3897/issn2541-8416.2018.18.4.162