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

The Beautiful Beast Globe Chamomile Oncosiphon piluliferum

But not the Chamomile Tea we drink… Chamaemelum nobile

Distinctive round “globe” flowers Globe Chamomile Oncosiphon piluliferum

Distinctive deeply segmented leaves Globe Chamomile Oncosiphon piluliferum

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

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

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

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

Ben Avery early emergence by November 2018

> 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

From roadways Globe Chamomile spreads into the open desert

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

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

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.

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

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

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

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

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

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

. 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