A Catalpa Tree Flower Under the Microscope

More testing of the higher powered stereo-microscope with this flower specimen from a catalpa tree on campus.

Anthers with pollen grains (~25x).

The catalpa tree leaf and flower for reference.

Large catalpa leaf and two flowers.
Detail of longitudinally bisected flower (~7x).
Closeup of petal (~35x).
The colors on the petals come from cells having different colors (~90x).

Lavender Flowers Up Close

Lavender flowers on the stage of the reflecting, stereo microscope.

In addition to the basic stereoscopes with their fixed 10x and 30x magnifications, we also acquired a zoom stereoscope for more serious research projects. I tried it out with a sprig of lavender blossoms.

Closeup of lavender flowers. Magnification 7x.

The clips on the stage weren’t particularly useful for holding something as small as a single flower, so, to see into the flower, I had to improvise with some of the dissection gear.

Holding the lavender flower upright on the stage with a dissection probe.

At larger magnifications, the focal depth is pretty small so it’s tricky trying to get the big picture. Even thought the camera didn’t quite capture it, you can make out the pollen grains.

Looking into a lavender flower from the top. Magnification ~45x.

I tried slicing the flower longitudinally to get a better look inside, and to see how difficult it would be to identify the major parts.

Longitudinal section of a lavender flower. Magnification 14x.

The photos turned out well using a point-and-shoot Nikon camera through the eyepiece, but even these pictures did not capture all the detail visible to the eye.

Lavender flower sliced longitudinally. Two stamens are clear visible. Magnifications ~50x.

With the 2x objective attached, the microscope gets up to 90x magnification, but it becomes very hard clearly see anything after about 60x. All in all, the optics are good, and the lights bright enough to make for a very nice microscope.

Drawing Daffodils

It’s spring, and what better time to study meiosis and dissect daffodils.

Students collect daffodils for dissection.

Daffodilusa (pdf) has nice description of how to dissect daffodils. However, I had students collect the flowers, and sketch the outsides and insides (longitudinal bisection) before I gave them the handout.

I wanted them to practice drawing diagrams and observing features first, before we got into the discussion of what the parts were and what they did, to make sure they’d not forgotten all they’d learned when we did our animal dissections last semester.

They laid out their grids, did some very nice drawings, and then labeled what they’d drawn, based on the handout, over the weekend.