Image: Mims Giant Ragweed 09052010 WITH BYLINE IMG 0829

Description: 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). This photograph shows Sarah Mims holding a giant ragweed whose height exceeds that of any we have found reported on the web. 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 appeared 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-655739 .php
Title: Mims Giant Ragweed 09052010 WITH BYLINE IMG 0829
Credit: Forrest M. Mims III
Author: Photograph by Forrest M. Mims III
Usage Terms: Creative Commons Attribution-Share Alike 3.0
License: CC BY-SA 3.0
License Link: https://creativecommons.org/licenses/by-sa/3.0
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