Virtual Microscopy
Microscopy Primer
License Info
Image Use
Custom Photos
Site Info
Contact Us

Visit Science,
Optics, & You

The Galleries:

Photo Gallery
Silicon Zoo
Chip Shots
DNA Gallery
Amino Acids
Religion Collection
Cocktail Collection
Screen Savers
Win Wallpaper
Mac Wallpaper
Movie Gallery

The Butternut

The Butternut or White Walnut (Juglans cinerea) is a hardwood tree that ranges from eastern Canada west to Minnesota and as far south as Mississippi. Unfortunately, this tree is being killed throughout its growth range by Sirococcus claviginenti-juglandacearum, a fungus most likely introduced from outside of North America. The sapwood ranges from white to light grayish brown in color and is rarely more than a single inch wide. In contrast, the heartwood is a lustrous light chestnut-brown and frequently variegated with pigment.

Cross Section

Radial Section

Tangential Section

More than 90 percent of all butternut trees in Ontario and western Quebec are now infected with the deadly canker. This disease has led to the butternut tree being placed on the endangered plant listing in the United States. Although use of lumber from this tree is restricted, wood from the butternut has been used for furniture, cabinets, instrument cases, interior trim, paneling, woodenware, toys, and novelties.

Microscopic examination of iron-alum hematoxylin and safranin stained thin sections (see the digital images presented above) reveal a semi-ring porous wood having simple perforation plates. Tyloses are fairly abundant in the sections and unstoried rays are one to four seriate and homocellular. Vessels are large, but few in number, with inter-vessel pits being 8 to 16 micrometers in diameter and orbicular to oval or angular (through crowding) in shape. Fiber tracheids are thin-walled with a medium to very coarse texture.


Questions or comments? Send us an email.
© 1995-2022 by Michael W. Davidson and The Florida State University. All Rights Reserved. No images, graphics, software, scripts, or applets may be reproduced or used in any manner without permission from the copyright holders. Use of this website means you agree to all of the Legal Terms and Conditions set forth by the owners.
This website is maintained by our
Graphics & Web Programming Team
in collaboration with Optical Microscopy at the
National High Magnetic Field Laboratory.
Last modification: Friday, Nov 13, 2015 at 02:19 PM
Access Count Since February 1, 1999: 27776
Microscopes provided exclusively by: