Palmer amaranth (left) and waterhemp (right). Palmer amaranth is closely related to other amaranth (pigweed) species and can be challenging to differentiate during the early vegetative stages. Amaranthus palmeri is a species of edible flowering plant in the amaranth genus. Rates higher than the 1 lb used in this trial should improve consistency. Palmer amaranth is on Minnesota’s prohibited noxious weed and seed list with the intention to eradicate Palmer amaranth before it becomes widely established in the state. Spiny Amaranth: The presence of spines or spine-like structures can lead to misidentification of Palmer ama-ranth as spiny amaranth. The Palmer amaranth-spiny amaranth cluster included a cluster of Palmer amaranth and two clusters of spiny amaranth, a monoecious species. Like corn and the These species have the same chromosome number of 2n = 34 (Gaines et al. It has already shown resistance to five major classes of herbicides across the U.S.. Male plants do not have these stiff bracts and thus have a softer feel Figure 5. The leaves of Palmer amaranth have a poinsettia-like leaf arrangement when viewed from above and an occasional v-shaped variegation or watermark on the upper surface of the leaf. Spiny amaranth plants were col-lected along with roots and transferred to 10-L pots containing field soil and allowed to grow indefinitely (Amaranthus species such as Palmer amaranth, spiny amaranth, etc. • Stems are hairless and smooth. Palmer amaranth’s seed heads are very long, ranging from ½ to 1½ feet in length. ; It originated in the southwestern U.S. and has high water-use efficiency, allowing it to thrive in drought conditions. 2005), and they Palmer amaranth plants lack hairs along the stem and leaves. A spiny amaranth × Palmer amaranth hybrid was confirmed resistant to several acetolactate synthase (ALS) inhibitors including imazethapyr, nicosulfuron, pyrithiobac, and trifloxysulfuron. Mature Palmer amaranth plants are without hairs, with leaves that are diamond or egg-shaped in outline, and petioles that are usually longer than the leaves (Figure 3). these plants were Palmer amaranth had read about the sharp bracts on female Palmer being painful to grab, and mistook these spines for the bracts. Palmer amaranth seedlings are emerging in Indiana and need to be properly identified. Palmer amaranth is not presently listed as being found in Canada, however, historically it has been found in scattered locations in Ontario: Forest - 1966, St. Thomas - 1978 and Niagara Falls - 2007. What makes Palmer amaranth such a difficult weed? spiny amaranth has a diagnostic pair of ¼ to ½ inch spines at the base of most leaf petioles and along the central stem. Palmer amaranth is one of the most difficult weeds to manage in the field. assigned as sister taxa in AFLP-based phylogenetic analyses (Wassom and Tranel 2005). Female palmer amaranth plants can have a prickly feel due to stiff bracts at the leaf axil. Only the female plants produce seeds. Thus the dioecious species Palmer amaranth and waterhemp may not necessarily hybridize with each other more readily than they would to one or more of the monoecious Amaranthus species. “Pigweed” as used here can refer to waterhemp, Palmer amaranth, spiny amaranth, Powell amaranth, and redroot/smooth pigweed (these two are mostly the same for ID/control purposes). The amaranth plant is a tall (approximately six feet), broad-leafed perennial, favorable to moist, loose soil. Palmer amaranth except two from Baldwin that are spiny amaranth). • Leaves often have v-shaped variegation. Once Palmer Amaranth develops a seed head it becomes easier to distinguish, as the terminal seed head is usually very long. The seeds from each field location were planted in a greenhouse in 20 pots with a 50/50 sand and organic potting soil mix. The characteristi c differences between common waterhemp and palmer amaranth are described. Palmer amaranth has no long thorns like spiny amaranth. spiny amaranth has a diagnostic pair of ¼ to ½ inch spines at the base of most leaf petioles and along the central stem. A single female plant Once pigweeds reached a height of 1 to 2 inches, they were treated with commonly used POST herbicides at 2X or 4X the Spiny amaranth can be differentiated from Palmer amaranth and waterhemp due to the presence of sharp spines at the point where leaves attach to the stem. In 2011, an herbicide-resistant cross between spiny amaranth and Palmer amaranth was discovered in Mississippi. This spiny bract is not common in redroot pigweed or in waterhemp. Palmer’s Amaranth was named in honour of Edward Palmer (1829–1911), a self-taught British botanist and early American archaeologist. • Flowering structure is much less branched than Can you tell the difference between Palmer amaranth, waterhemp and redroot pigweed? The Minnesota Department of Agriculture (MDA) has confirmed Palmer amaranth for the first time in Winona County. When scouting this time of year, be on the lookout for pigweeds with long terminal seed heads (up to 2-3 feet long) and long petioles (longer than the … In seed burial trials where the seeds were on the soil surface, emergence was 56 and 68% for spiny amaranth and slender amaranth, respectively. While many Amaranth varieties are seen as annoying weeds, several are cultivated as food crops. Like all pigweeds, Palmer amaranth is a C 4 species, making it very efficient at fixing carbon and well-adapted to high temperatures and intense sunlight. Figure 4. These spines are sometimes mistaken for the sharp bracts on female Palmer amaranth infloresences. Spiny amaranth is a monoecious plant with both male and female flowers on the same plant. These spines are up to ½ inch in length. The reddish central stem is smooth with relatively no hairs.
2020 spiny amaranth vs palmer amaranth