Micromorphology of DFW Metroplex Fern and Lycophyte Spores

October 08, 2019

This article was written by Ivan Rosales, 2019 BRIT Summer Intern and student at University of Texas at Arlington. Ivan interned with Dr. Alejandra Vasco, working on fern diversity and anatomy.

 

Who Would Have Thought to Look?

The Micromorphology of DFW Metroplex Fern and Lycophyte Spores

Anthony van Leeuwenhoek was a scientist from the Netherlands who discovered and described for the first-time bacteria, microscopic protists, sperm cells, blood cells, microscopic nematodes, rotifers, and much more. Even centuries after Leeuwenhoek first looked at a drop of pond water through his early microscope invention and saw microscopic creatures, people still asked, “Who would have thought to look?” I asked myself the same question after seeing my first mounted fern spore using BRIT’s Scanning Electron Microscope (SEM) at the George C. and Sue W. Sumner Molecular and Structural Laboratory.

Dr. Vasco and Ivan sitting at the scanning electron microscope
Dr. Alejandra Vasco and Ivan Rosales using the Scanning Electron Microscope (SEM) at the Botanical Research Institute of Texas

This summer during my internship at BRIT I worked with an avid fern expert, Dr. Alejandra Vasco, constructing a collection of SEM photographs of the spores of the fern and lycophyte species native to the DFW Metroplex. These spores can hardly be seen with the naked eye but have very interesting appearances when seen using a powerful microscope. The SEM is a very powerful tool in research, that can be used to view things unimaginably small. It uses an electron beam against what you want to see, in this case spores, and the image seen on the computer screen, rather than through a lens, is simply the electrons reflecting off it.

But, how do you prepare spores before they can be imaged? First you have to find spores! Ferns are quite different compared to the plants most people are used to seeing in that they disperse using spores and have no flowers or seeds. Fern spores can be found in the undersurface of the leaves inside small capsules called sporangia, that when fresh look like caviar. Spores can be found in live plants or herbarium specimens and for my project I used the collections deposited in the BRIT herbarium. I first pulled out all fern and lycophyte collections belonging to the DFW metroplex. Then, using a dissecting microscope, I removed 3-4 sporangia from some specimens and mounted them onto 15 mm SEM pins with double side carbon tape. I then carefully opened the sporangia with a dissecting needle and spread the spores on the tape. After that the spores are ready for viewing. The pin with spores is placed inside the viewing chamber of the SEM, air is evacuated from the chamber, and the specimen is ready for observation. Multiple parameters are then assiduously adjusted for the best image.  

Sporangia shown with spores in the periphery under a dissecting microscope
Sporangia shown with spores in the periphery under a dissecting microscope
Spores mounted onto 15 mm SEM pins ready for imaging
Spores mounted onto 15 mm SEM pins ready for imaging

One would imagine that spores are perfectly round and smooth with very few surface features. However, during my internship I gained an appreciation for the complexity of plants after seeing how much there is to learn about these microscopic fern spores. Using the SEM was a very enthralling experience because of how powerful it is for capturing images with great detail. Much like with Leeuwenhoek’s observation of pond water hundreds of years ago, I ask myself the same question about these fern spores: “Who would have thought to look?”

Image of Asplenium platyneuron (Ebony spleenwort) spore
Image of Asplenium platyneuron (Ebony spleenwort) spore
Image of Thelypteris kunthii (wood fern) spore, showing monolete mark
Image of Thelypteris kunthii (wood fern) spore, showing monolete mark
Image of Pteris multifida (spider brake) spore, showing trilete mark
Image of Pteris multifida (spider brake) spore, showing trilete mark

 

Leave A Response

Plain text

  • No HTML tags allowed.
  • Lines and paragraphs break automatically.
  • Web page addresses and email addresses turn into links automatically.

Related Articles

Survey of BRIT’s Tarrant County Bryophyte Collection

Bryophytes, defined by their lack of vascular tissue, are a category of smaller plants that include the mosses, liverworts, and hornworts.
Read More >

BRIT’s Computer Vision(aries)

This summer, four high school students from Trinity Valley School interned at BRIT through our Junior Volunteer/Intern program. These students were given the task of applying their computer science background to the challenge of helping BRIT create a quick and easy way to determine the fullness of our herbarium cabinets. By better understanding the details of the capacity of the cabinets, BRIT will be able to strategically plan for future growth and management of the herbarium collections. L to R: Ashia White, Kevin James, Jason Best, and Jacob Haydel I worked with students Grace Beasley, Jacob Haydel, Kevin James, and Ashia White to explore the process of using computer vision technology to analyze images of the open cabinets. We set out to extract details of each cabinet’s structure and...
Read More >

Books, Botany, and Bugs

This article was written by Sydney Jackson, 2017 BRIT Summer Intern and student at Austin College in Sherman, TX. This past summer, summer of 2017, I was a research intern at BRIT. When first coming to BRIT I did not know what to expect. All the perceptions of internships that I had in my head were of interns running back and forth delivering coffee and dry cleaning to any staff member that asked. Luckily BRIT blew all of those premonitions out of the water and showed me what a great internship should really strive to be. During my internship I worked on three main projects with plenty of other small projects sprinkled in between (oh, the joys of a non-profit). The first one I encountered was helping digitize the rare book collection by scanning beautiful illustrations and photo slides. On...
Read More >

My Summer Education: The Microscopic World

This post was written by Vanessa Marshall, 2017 summer intern and student at The University of Alabama. BRIT has been amazing – a catalyst that has unlocked the doors to the natural world and shown me wonders that I had never fully appreciated. I have always loved hiking, climbing trees, being outside in general, but my connection to the surrounding plant-life was distant, similar to the relationship between a homeowner and the trees that form the hardwood floors. I appreciated plants’ beauty and enjoyed the shade, but now there is a definite connection between my (limited) scientific knowledge and the physical plants. It means so much more to know the scientific name of a tree you just ran past, or to recognize Vitis mustangensis and know that you can eat the wild grapes growing on the vi...
Read More >