Download Eight Key Points to Palmer Amaranth and Waterhemp Identification

Eight Key Points to Palmer Amaranth and
Waterhemp Identification
Leaf blade watermark
Appearance of weed seeds
Small dark brown-black seeds like other pigweed species (NM
State Univ. and WNMU).
Lack of hairs
Occasional dark red/purple or white water or “V” mark or
patch on leaf blade of Palmer amaranth (Penn State).
Leaf tip hair
Both Palmer amaranth (left) and waterhemp lack hairs on the
stem, petioles, and leaves compared to redroot (right) or
smooth (Purdue Univ.).
Leaf shape
Seedling leaves of Palmer amaranth are broad ovate or
egg-shaped vs. more narrow lanceolate-shaped leaves of
waterhemp. Like other pigweeds, young leaves with notched
tip. (Univ. Illinois).
Palmer amaranth leaves can sometimes have a single short
hair at the tip of the leaf blade. (Univ. Illinois).
Petiole length
bottom (University of Illinois and Purdue University).
Floral structures
Palmer amaranth flower head has prickly larger female and
soft more narrow male on separate plants (Penn State)
Palmer amaranth petiole is often longer than the leaf blade.
(Purdue Univ. top and Penn State bottom). Waterhemp petiole
not longer than leaf blade.
General appearance
Female flower heads of Palmer amaranth bottom and
waterhemp top (Iowa State).
Starting on the left; inflorescences of Palmer, Powell, redroot,
smooth, and waterhemp. (A. Hager, University of Illinois)
Whorled or poinsettia type appearance of Palmer (top) and
long lanceolate leaves and waxy leaf surface of waterhemp at
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Eight Key Points to Palmer Amaranth and Waterhemp Identification
Contact Information
William S. Curran
Professor of Weed Science
[email protected]
814-863-1014
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Eight Key Points to Palmer Amaranth and Waterhemp Identification