Flatspine Bur Ragweed
Ambrosia acanthicarpa
Observed in the ponderosa forest near the campus of Northern Arizona University in Flagstaff, Coconino Co., Arizona, USA. August 2009.
Sponsored Links:
FLOWERS: The greenish flowers turn yellow by virtue of abundant pollen
(hayfever antigen). In spikes with separate male and female flowerheads.
FRUIT: The bracts enclosing the seed soon form large, purplish color
spines that are noticeably flattened.
LEAVES: Leaves are deeply divided into narrow segments and are very
similar to other ragweed species.
ANNUAL: Few plants surpass one meter
in height and there are usually several branching stems from base.
RANGE: Common in Arizona's ponderosa woodlands after good summer rains.
Found in relatively moist habitats through much of western North America.
UNARMED. The bur points are a slightly sharp.
Asteraceae -- Sunflower Family
More Information:
- Southwest Environmental Information Network
- Jepson Manual
- USDA Plant Profile
- ITIS Taxonomic Report
- Google Images
- Google Scholar Literature Search