Analysis of Rose Flower Surface Structure under a Scanning Electron Microscope

by Omer Ropri

Institute of Optics University of Rochester, Rochester, NY


This exercise has explored the surface structure of a Rose petal and a Rose leaf on a microscopic scale and then compared the results to images found in literature in order to identify the observed features. Some Images that did not exactly compare with those found in literature have also been included and comments have been made about how they might be interpreted. These images could be extremely useful for biologists studying microstructures in plants. The images were taken using a Scanning Electron Microscope (SEM) and details of how to obtain good images in the SEM have been discussed.

Image of Particular Rose Plant Under Inspection

Figure 1: Rose Flower. This digital camera image displays the particular kind of Rose plant that was inspected

Sample Preparation: Coating and Critical Point Drying (CPD)

Figure 2: SEM image of Rose petal. This is one of the images of the Rose Petal that was taken during this exercise. The cracking that can be seen in the 'valleys' is the cracking of the layer of gold over time.

SEM Images (Rose Leaf)

Figure 3: Cellular and Vascular (white) structure of the leaf

Figure 4: Cellular and structure of the leaf at a higher magnification

Figure 5: Picture of the leaf Stoma at even higher magnification

Literature Images (Rose Leaf)

Figure 6: Pictures of Rose Leaf from Literature. It is visually very easy to compare theses images to the ones taken from the SEM. Reference (1) and (2).

SEM Images (Rose Petal)

Figure 7: Cellular structure of the Rose Petal at successively higher magnifications

Figure 8: Vascular structure of the Rose Petal at successively higher magnifications

Literature Images (Rose Petal)

Figure 9: Images from literature of rose-petal-papilla-cells (Reference 1)

An SEM Image and Technique

Figure 10: Two different images of the same area taken with different SEM settings. Firstly, based on observation of earlier images, this image probably shows the boundary between the cellular and vascular structure within the rose petal The image on the right is recorded using a slower scan rate (also artificially colorized). We can see that a slower scan rate produces a better picture in this case by getting rid of bright areas in the picture. This is because a slower scan rate is comparatively able to eliminate more noise from the picture.

Image Feature Size Calculations

In imageJ (Image Processing Software) the beginning and ending coordinates of the line drawn through the center of the stoma as shown in the picture below (black line) are given as '265' and '829' in the horizontal direction. These coordinates denote the number of the pixel in the image. On the 2 um line in the image the coordinates go from '22' to '72'. So if 50 pixels are 2 um long by setting up a simple proportion we are able to say that the image feature covered by the black line is about 23 microns long in terms of its actual size.

Figure 11: Image feature size calculation. The stoma is about wide at its widest point in the horizontal direction. i.e. the size of the black line drawn is about 23 microns

Simulation of Electron Flight Trajectories

An electron flight simulation software was used to simulate 2000 electron trajectories with an organic sample as was used in this exercise. The software uses Monte Carlo simulations. Based on the results it can be seen that the electron beam volume interaction with the sample is about 5 microns wide and 6 microns deep. This gives us a good indication of where we are collecting our image information from within the sample.

Figure 12: Electron Flight Simulation for an organic sample


This project may someday be useful for somebody for its currently unrecognized scientific value. More importantly, However, it has taught me how to make a website and a poster and to do some awesome electron microscopy