Conifers
View of general outline
View of bough of Pinus resinosa
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).
These usually develop in early may in Dane county
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
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.