1. GlobE Chamomile (Oncosiphon piluliferum).
CAZCA Meeting
Desert Botanical Garden Phoenix
22 January 2019
John Scheuring
Conservation Committee Chairman
The Arizona Native Plant Society

2. The Beautiful Beast
Globe Chamomile
Oncosiphon piluliferum

3. But not the Chamomile Tea we drink…
Chamaemelum nobile

4. Distinctive round “globe” flowers
Globe Chamomile
Oncosiphon piluliferum

5. Distinctive deeply segmented leaves
Globe Chamomile
Oncosiphon piluliferum

6. The Beautiful Beast : Growth
A winter annual
Germination, growth, and dispersion favored by wet years
Germinates in November and December
Flowering is triggered by the winter equinox
Seed ripening and dispersion starts in February
Seed dispersion continues to late May in wet years
Globe Chamomile
Oncosiphon piluliferum

7. The Beautiful Beast : A foreigner
Native to South Africa
Currently considered an invasive
Soon to be classified as an Arizona Noxious Weed
Globe Chamomile
Oncosiphon piluliferum

8. The Beautiful Beast in Arizona
In Arizona first reported in Maricopa County in 1990s
By 2005 it had infested Ben Avery facility, Cave Creek USFS Ranger station, and parts of the Tonto
By 2015 it had heavily infested lower I-17
With wet year 2016 there was an explosion throughout the Phoenix Metro area
Globe Chamomile
Oncosiphon piluliferum

9. The Beautiful Beast Spread in Arizona
The infestation of the Ben Avery facility provided a perfect storm for infestation in Maricopa County
It was allowed to bulk up unimpeded for over 15 years
Seed ripening coincided with the annual Arizona Outdoors Exposition in late March-Early April
Seed has been dispersed by thousands of visitors over many years
Globe Chamomile
Oncosiphon piluliferum

10. Ben Avery early emergence by November 2018

11. > Seeds drop from vehicles when they decelerate and accelerate > I 17 on and off-ramps ramps Carefree to -New River became rife with globe chamomile

12. From roadways Globe Chamomile spreads into the open desert

13. Winter 2016/17 widespread throughout Phoenix metropolitan neighborhoods
Very favorable winter rain distribution resulted in multiple generations between December 2016 and May 2017
Opportunistic infestations throughout Phoenix neighborhoods >> Cave Creek to Mesa.
Growth in road and sidewalk cracks throughout Central Phoenix
Found throughout the Tonto NF

14. Winter 2017/18 dry Summer and Fall 2017 followed by little or no emergence
Little or no visible emergence in Phoenix and Tucson areas
No major infestations spotted

15. Winter 2018/19 wet Summer and Fall 2018 followed by massive emergence
Plant emergence at Tucson Prince Rd site by early November 2018
Massive early plant emergence at Ben Avery Shooting Range
We must be prepared for a major spread of Globe Chamomile in the Phoenix metro area this season and new infestations throughout Tucson.

16. The Beautiful Beast : What can we do ?
Stop the spread from hotspots
But Glyphosate herbicide does not work
Trichlopyr at low rates works well
Globe Chamomile
Oncosiphon piluliferum

17. The Beautiful Beast : What can we do ?
Globe Chamomile
Oncosiphon piluliferum

18. The Beautiful Beast : What can we do ?
Globe Chamomile
Oncosiphon piluliferum

19. The Beautiful Beast : What can we do ?
Globe Chamomile
Oncosiphon piluliferum

20. The Beautiful Beast : What can we do ?
Keep plants from flowering and going to seed
Dig them up in urban landscapes
Use Trichlopyr (Garlon) at low rates to cover a lots of ground
Globe Chamomile
Oncosiphon piluliferum

21. The Beautiful Beast : What can we do ? Awareness Awareness Awareness
No one knows about Globe Chamomile !!
It was proposed to be added to the AZ Noxious Weeds List in 2007
BUT in 2008 Gov Brewer imposed a moratorium on all state rule changes
That moratorium was reinstated by Gov Ducey in 2014
AZDA has sent new rule change wording to the Governor and legislature for expected approval by April 2019…..
Globe Chamomile
Oncosiphon piluliferum

22. . Globe Chamomile : Summary Oncosiphon piluliferum
Winter composite annual, Dec-May
“Herbage with Vile Odor”
Also called “Stinknet”
Distinctive dark green “carrot like” foliage
Distinctive round and bright yellow flower clusters
Origin South Africa
Easily establishes in disturbed soils
Prodigious growth and seed production
Remarkable aerial seed dispersal
Current hotspots : Riverside Cty CA and Maricopa Cty AZ
Glyphosate herbicide is ineffective
Garlon (trichlopyr ai) herbicide is recommended