Conifers

return


Pine Life Cycle

Stages of Pine Life Cycle

Microsporangiate Stages:

Recognize microsporangiate strobili in Pinus and recognize that these consist of a central axis (stem) with attached microsporophylls. Recognize microsporophylls, microsporangia (pollen sacs), and pollen grains (microgametophytes).

Megasporangiate Stages:

Recognize megasporangiate strobili in Pinus and recognize that these consist of a central axis (stem) with attached seed scale comlexes. Recognize seed scale complexes; sterile bracts; seed scales; ovules, nucellus (megasporangium); integuments; mother spore mother cell (and that this cell is diploid), pollen chamber, megagametophyte, archegonia with eggs (and that the eggs are habloid).

Embryo and Seedling Stages:

Recognize the seed (mature ovule), and all the parts of the seed - megagametophyte, embryo (as a sporophytic stage), cotyledons, apical meristem of the shoot and root; seedlings and cotyledons of germinating seedlings.

  • View of dissected seed showing embryo and female gametophyte
  • View of dissected seed showing cotyledons
  • View of longitudinal section through a seed
  • View of stages of germination


Go to General Description of the Conifers

Return to Lab themes