Pine Life Cycle
Stages of Pine Life Cycle
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).
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).
- View of bough with megasporangiate cones at time of pollination
- Detail of megasporangiate cones at time of pollination
- Habit view of 8-month old cone
- Whole 8-month old cone
- Dissected 8-month old cone - view of ovules
- Seed-scale Complex: detail of ovules
- Seed-scale complex: view of two sides
- Longitudinal section of young megasporangiate cone
- Longitudinal section: view of seed-scale complex
- Longitudinal Section: view of ovule with pollen chamber and megaspore mother cell
- View of older seed scale - megagametophyte with archegonia
- View of megagametophyte with archegonia
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