Wednesday, December 9, 2009

Frozen, Pressed, and Glued

Mountain Camellia (Stewartia ovata), a mountain disjunct that is rare in our area.

It was a packed house for the Virginia Native Plant Society tour of the new home of the William and Mary Herbarium, led by curator Beth Chambers. I felt bad because I've never had to turn people away from a field trip before! Herbariums are collections of plant specimens that are mounted and labeled with their scientific name as well as information about when and where they were collected.
The William & Mary herbarium, housed in the Integrated Sciences Center, specializes in plants of the southeastern coastal plain. Focusing on a specific region makes the herbarium more useful to visiting botanists. William & Mary has the third largest herbarium in the state, with Virginia Tech being the largest.

Preservation of specimens is a big issue for herbariums. The state's second largest is Longwood College, but they have no curator and the collection sits untended in a basement (yikes!). Beth jokingly said she will consider her job well done as long as the specimens here survive her tenure.
Right now, the herbarium houses 76,000 specimens like the Hexastylis (heartleaf) above. More than half of the specimens have been collected by students. The new facilities give the collection room to expand up to 100,000 specimens. Unlike other collections, William & Mary's herbarium is arranged alphabetically instead of phylogenetically (by biological evolution). There are usually several specimens of each species, to cover different times of year and variation in the appearance of a species. The cabinet below contains dozens of samples that are waiting to be processed.
Bugs are a big problem for the herbarium, so all samples that come in are frozen for 10 days to three weeks to kill things like cigarette beetles. Fire suppression is also a concern. The sprinklers over the cabinets make Beth a little nervous.

Herbarium assistant Rachel Anderson demonstrated for the group how specimens are mounted. She seemed a little suprised by the attention she was getting.
First Rachel spread glue out on a piece of plastic. The herbarium uses Missouri glue, which is a special glue formulated to the specifications of the Missouri Botanical Garden herbarium. She then placed a plant specimen (it looks like partridge pea) on the glue.
After that, the specimens are glued on acid free paper. Any part of the plant that falls off goes into a paper fragment packet.
In another part of the lab, Beth set out some especially nice mounted samples of plants like the mountain camellia pictured at the top of the post.
Below is a specimen of Cypripedium kentunckiense. A small population of this plant was discovered not to long ago in a small spot on the Northern Neck of Virginia. It's the only place in the entire state where you can find it naturally occuring.
There was also a microscope on hand so we could get a better view. What do you think Alice...is that leaf hirtellous or pilose?
For this tour we had a special guest, Gus Hall (pictured below), who was the director of the herbarium when it started way back in 1968. Gus said he was amused that the molecularists (biolgists) were always surprised at the amount of activity taking place in the herbarium. Many members of Phi Beta Kappa worked there and several well know biologists came out of the program including Jeff Doyle and Doug Soltis.
Thanks for the tour Beth!

11 comments:

Phillip said...

Another fascinating post. I wouldn't mind having that mountain camellia framed and hanging on my wall. Very beautiful.

How It Grows said...

Know that I know where it is, I'm planning to go see it in bloom next year.

Janet said...

Sounds like a great field trip. How delicate those samples must be. So, where is the Stewartia?

How It Grows said...

They're rare, so I don't know if I can say exactly...I'll have to tell you in person sometime.

tina said...

I have a question for you. I am trying to identify an evergreen groundcover that grows under cedar trees. It looks like it even has scales like the Eastern red cedars but is only 4" high and spreads by long tendrils. It does not climb. I seem to remember either you or Les on one of your field trips talked of it. Do you know what I am talking about? The groundcover is evergreen. Was it you and can you help me out with the ID? Thanks.

How It Grows said...

Sounds like it's a species of Lycopodium (running cedar).

tina said...

Yes! That is it! You're a genius as I could not find it anywhere. Thanks! Have a great holiday too!

James Golden said...

I enjoyed that. Thanks for the visit.

WashingtonGardener said...

I have a Victorian-era herbarium album put together by a home hobbyist - so fascinating to look through and to think of all the others who scrapbooked all their plant finds during that time period - guess we all do that online now on our blogs :-)

Susan aka Miss. R said...

I tagged you in my blog post...
http://www.susancohangardens.com/blog/?p=1956

How It Grows said...

10 honest things that are also interesting? That might take some time.