September 21, 2006

Feature Article - for release the week of September 24, 2006

Dan Culbert - Extension Horticulture Agent 

Root Beer, Physic Nuts & Botany

Last week I was asked to give a presentation to a group of Master Gardener trainees in Dade County.  My subject was basic botany, which can be a tough subject to cover in a few hours.  I did my best to leave them with the idea that plants identification is a lot easier if the plant family can be figured out. 

I should listen to my own advice.  A recent visitor from Fort Drum brought in a plant for identification.  Somehow, the leaves and stems reminded me of another plant that I identified early this summer, the Root Beer Plant.   I spent a lot of time searching for the identity of my mystery plant among the Pepperomia family.  Our Master Gardeners beat me to the punch, as they remembered to look at the fruit of our mysterious specimen, and identified it as the Physic Nut. 

Today’s column will not only tell a little bit about these two plants, but is a good take home message for budding botanists:  look at all the evidence available when trying to find out more about plants in our Florida Yards. 

Botany Basics

The science of plant biology is a work in progress.  According to Wikpedia, an on-line encyclopedia, there are as many as 400 different families of plants.  Some are well know, like the rose or lily family.  Others are relative unknowns, such as the Krameriaceae, which includes one species of an obscure South American herb, the Peruvian Rhatany.  

One can easily get lost in the jungle of botanical names, so let’s leave this topic quickly.  But the one thing to remember is that flower and fruit structures have been the basis for lumping plants together in families or splitting them into different groups.   An in many cases, other family characteristics are the same across all members of a plant family. 

Aggressive Root Beer Plant

This Root Beer Plant sucker was growing in an  Okeechobee garden.  It was about 12 inches tall in June, 2006. Photo: Dan Culbert, UF/IFAS

Full sized leaves in September measured 8 x 12 inches. Photo: Dan Culbert, UF/IFAS

The spadex flowers of Piper auritum grow from the base of each leaf when the plant reaches a height of about 3-4 feet. Photo: Dan Culbert, UF/IFAS

Early this summer I received an email from a local lady.  Elaine Davis sent me a digital photo of a plant that she had acquired.  She was growing it in her back yard and was concerned about its invasive habitat, and wanted to know more about it.  The research process started with the steps needed to clearly identify the plant in question. 

She told me it was commonly called the Root Beer plant, so named because of the smell that came from crushed leaves and stems.  It has been reportedly used as a wrapper leaf in Latin American cooking and has some reputed medicinal values.  We also found that this plant was becoming an aggressive invader in Hawaii, Micronesia, and even in some places in the American tropics. 

Locating the botanical name of Root Beer plant as Piper auritum allowed us to find out more information, but positive identification would have to wait until it produced some flowers.  So I asked Elaine to let me know if she saw this plant produced some stick-like flower stalks, the “spadex” that is typical of Peace lilies, philodendrons, and several other plant families. This week she noticed the flowers, and we confirmed the identity. 

Poisonous Physic Nut

Our Fort Drum resident brought in several generous stems of leaves from her mystery plant, and included was an overripe, rounded fruit with three large black seeds.  The stems had a big bump at the node – where the buds are -- and it somehow reminded me of the Root Beer plant.  I went right to my books, looking among the other Pepperomias to see if I could find a reference to our mystery plant.

Meanwhile, our Master Gardeners started the tedious process of going through picture books, comparing the pictures to the specimen.  Lady Luck was on their side, as Master Gardener Terry Lane stumbled into a photo in one of our poisonous plant books that was a close match.  And on closer inspection and review, she suggested that it could be the Physic Nut, Jatropha curcas.

I read the description of the fruit, and then went back to the bag and saw what I had overlooked.  A later visit to the Fort Drum home of Veronica Ware confirmed that indeed the mystery plant was this distant relative of the poinsettia, a member of the Euphorbia family.

Besides the failure to follow the rules of looking at the fruit first, another piece of evidence that threw me was the discrepancies between some of our references: one reference reported the leaves could be cooked and consumed, and the fruit was known to be “dangerously eaten.” 

Mrs. Ware said that she knows of people who had consumed this plant.   My suggestion is more cautious: if the face of conflicting evidence, I will err on the side of caution and let people know that since some report it as poisonous, consuming it may not be a healthy thing to do.  Besides, I noticed that the botanical name puts it in the same genus as two other ornamental plants that are very poisonous, the Coral Plant (Jatropha multifida) and the Peregrina (Jatropha integerrima.) 

Another interesting fact about this plant is that it is being grown in India and other places as a source of oil which is squeezed out of the seed of the Physic Nut.  Experts are looking to the Physic Nut as a sustainable producer of bio-diesel fuels.  While these nuts could be grown for their oil, it will take more research to determine if it would be profitable for these poisonous fruit can fuel our energy needs. 

I’ve placed more information on our Okeechobee web page, http://okeechobee.ifas.ufl.edu.  If you need additional information on basic botany or these particular plants, please email us at okeechobee@ifas.ufl.edu or call us at 863-763-6469.  Local residents can stop by our office at 458 Hwy 98 North in Okeechobee, and visit our Okeechobee County Master Gardeners from 1 to 3 PM on Tuesday afternoons.  

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Trade names, where used, are given for the purpose of providing specific information. They do not constitute an endorsement or guarantee of products named, nor does it imply criticism of products not named. The Florida Cooperative Extension Service - Institute of Food and Agricultural Sciences is an equal opportunity/affirmative action employer authorized to provide research, educational information, and other services to individuals and institutions that function without regard to race, color, sex, age, handicap, or national origin.  Florida Cooperative Extension Service / IFAS / University of Florida.  Millie Ferrer, Interim Dean Last update: 03/09/2009 .  This page is maintained by Dan Culbert 

references

Anonymous.  Root Beer Plant.  Encinitas, CA: Trade Winds Fruit webpage, 2006. http://www.tradewindsfruit.com/root_beer_plant.htm 

Culbert, D.F.  Plant Jatropha for Dependable Color.  Okeechobee: UF/IFAS Cooperative Extension Service, March March 22, 2006. http://okeechobee.ifas.ufl.edu/News%20columns/Jatropha.htm 

Duke, James A.  Jatropha curcas. In: Handbook of Energy Crops.  W. Lafayette: Purdue University Center for New Crops:  1998. http://www.hort.purdue.edu/newcrop/duke_energy/Jatropha_curcas.html 

Lee Ling, Dana   Piper auritum  (on-line botany class notes). Pohnpei, Federation of Micronesia: College of Micronesia, 5/2000. http://www.comfsm.fm/~dleeling/invasive/hawaiian_sakau.html 

Jyot, Ratan. The cultivation of Jatropha curcas (website).  India:  Sai Petrochemicals , 2006. http://www.svlele.com/jatropha_plant.htm

Whitinger,Dave. Root Beer Plant, Hoja Santa: Piper auritum (Plant Profiles).  Bryan, TX: Dave's Garden Website,8/06.  http://davesgarden.com/pf/go/530/index.html

Wikpedia. Plant Families. 2006.  http://en.wikipedia.org/wiki/Category:Plant_families