The Most (or is it "Least"?) Wanted

Daley Ranch is no different from any other area in Southern California; the climate is perfect for growing just about anything, and non-native plants absolutely thrive here! These plant species can cause a lot of harm because the animals (and other plants) that call Daley Ranch "home" didn't evolve with these invasive species. As such, the non-native plants face no predators, and birds and other animals won't see them as nesting sites. With reduced competitive pressures, the non-natives often overwhelm slower-growing native plant species, and can actually "competitively-exclude" the natives from a habitat. That's a nice euphemism for saying that the native plants can be forced into extinction, at least on a local scale.

Non-native plants are categorized as to their ability to cause harm to habitats as a whole, and to other plant species (through displacement) in particular. These categories are defined, assigned and maintained by the California Invasive Plant Council (Cal-IPC). Cal-IPC describes many non-native plants as "Naturalized", meaning that even though they're living and reproducing in the wild, they're not really causing any harm. Other plants fall into the categories of Moderately and Highly Invasive, meaning that they have the potential to dramatically alter a habitat, degrading the landscape for our native plants and animals. Click on the Cal-IPC logo (when present) under the plant name to get more detail about the problems caused by the plant -- and how to eradicate it!

Examples of a Naturalized non-native include the Scarlet Pimpernel (Anagallis arvensis), a spring-time bloomer seen not only along the trails of Daley Ranch, but also in pretty much everyone's garden! At the other end of the spectrum, the nastiest and most-problematic invaders you'll see at Daley Ranch include Sweet Fennel (Foeniculum vulgare) -- see below. There are also lots of non-native, invasive grasses (e.g., Bromus spp.) on Cal-IPC's lists that have already become inexorably established throughout Daley Ranch.
Short-pod Mustard
Hirschfeldia incana
By Anonymous (Own work) [CC-BY-SA-3.0 ( or GFDL (], via Wikimedia Commons
Yellow Starthistle ("Tocalote")
Centaurea melitensis
By Eugene Zelenko (Own work) [GFDL ( or CC-BY-SA-3.0-2.5-2.0-1.0 (], via Wikimedia Commons
Russian Thistle
Salsola tragus
Forest & Kim Starr [CC-BY-3.0 (], via Wikimedia Commons
Poison Hemlock
Conium maculatum
This image is a work of the Natural Resources Conservation Service, part of the United States Department of Agriculture, taken or made during the course of an employee's official duties. As a work of the U.S. federal government, the image is in the public domain.
Sweet Fennel
Foeniculum vulgare
By Karelj (Own work) [Public domain], via Wikimedia Commons
Convolvulus arvensis
By Frank Vincentz (Own work) [GFDL ( or CC-BY-SA-3.0 (], via Wikimedia Commons
Photographer unknown. Santa Monica Mountains National Recreation Area, California, USA. Taken at Rancho Sierra Vista/Satwiwa. NPS photo, no copyright.
Silverleaf Nightshade
Solanum elaeagnifolium
Photographer: Rob Mustard. You want it, use it!
Purple Salsify
Tragopogon porrifolius
Photographer: Rob Mustard. You want it, use it!