Record (?) Texas Giant Ragweed (cut 05 September 2010)

Ragweed is among the worst enemies of allergy sufferers, and the giant ragweed (Ambrosia trifida) is widely considered the worst of the worst. Official reports claim that giant ragweed can reach a height of 17 feet (5.18 meters) in one season (see http://www.extension.purdue.edu/extmedia/BP/GWC-12.pdf). Some unofficial reports on the web claim that wild giant ragweed can reach 20 feet (6.1 meters). Considerable wild giant ragweed is now growing on our place in South Central Texas, and on 05 September Forrest M. Mims III and his daughter Sarah Mims staged a hunt for the tallest specimens. Here's a photo of the tallest they found:http://www.facebook.com/?sk=inbox&setup#!/photo.php?fbid=490066642801&...­o.56280362082&theater MEASUREMENT METHOD: Of the four very tall plants that we sampled, the tallest measured an astonishing 21.05 feet (6.416 meters) as carefully measured with an Olympia Tools E-Z Read metal measuring tape. This height exceeds both the official and unofficial heights for giant ragweed that can be found in a search of the Web. The plant was carefully measured from the cut base (about an inch above ground level) to the tip of the highest flower (which was not fully emerged) by means of an Olympia Tools E-Z Read metal measuring tape. Sarah held the end of the tape at the cut base of the plant and Forrest pulled the tape to the end of the highest flower. The slight curvature of the plant was not artificially altered. More details and a photograph of Sarah holding the world's tallest giant ragweed are in my weekly science column in the SAN ANTONIO EXPRESS-NEWS on 13 September 2010 and the SEGUIN GAZETTE-ENTERPRISE on 10 September 2010. http://www.mysanantonio.com/default/article/In-search-of-the-giant-ragweed-65... .php

Category:

Science & Technology

Tags:

• ragweed
• giant ragweed
• hay fever
• allergy
• Forrest Mims