Pollen Type: Weed
Cross-Reactivity: Redroot Pigweed, Spiny Pigweed, Western Waterhemp
HS Allergy Extract: Careless Weed; Careless/Pigweed (CR)
Genus/Species: Amaranthus palmeri
Common Names: Careless Weed, Palmer’s Amaranth
Distribution: Interior valleys of central and southern California eastward to Colorado, Kansas, Missouri and eastern Texas.
Locations: Frequently found along roadsides, ditches and fields. It’s also found in lower and upper deserts. Careless Weed spreads rapidly.
Pollination Method: Wind-pollinated
Pollinating Period: Summer
Description: Careless Weed is an upright, stout-stemmed annual, growing 1½’-6’ in height. Its leaves are pale green, oval-shaped, and have stems (petioles) as long or longer than the blade. Its flowers grow in long, slender spikes. Careless Weed is dioecious, meaning the male and female flowers grow on separate plants. Spine-tipped leaflets make the spikes sharp to the touch, especially so when the female is in bloom. Careless Weed produces pollen in extreme amounts, much exceeding the quantity shed by a more widespread Redroot Pigweed.