Rubio Canyon


The Native Plants of 
Rubio Canyon

Fragrant California Brickle Bush

    The dry landscapes of Southern California are home to hundreds of water and nutrient conservative, slow growing native plants.  They thrive in long dry summers, survive and re-establish themselves after fire, but have difficulty competing with fast growing invasives.

Wand Buckwheat

    The palette of native plants in Rubio Canyon is a fine representation of Southern California’s transverse range plant communities.  Our steep, rugged and diverse terrain offers opportunity for hundreds of native plant species, and many that have been introduced from around the world.

California Fuchsia

Coast Wild Buckwheat

California Fuchsia

Native Rye Grass

One of the Popcorn Flowers

Poison Oak



Rubio Falls, Altadena, California, circa 1920

    Rubio Canyon crowns the city of Altadena near Los Angeles,  California.  It is rich in local history, hosting the Mt. Lowe Railway's famous incline trolley to Rubio Pavilion, and on to the Mt. Lowe Tavern.  It is a destination for local recreational hikers as well as a natural source of fresh water, serving about 200 homes in the immediate area.
On a hike to the falls of Rubio, three major invasive plant populations are easily visible, taking a strong hold in the aftermath of the major water events of 2005.
Non-native plants are species introduced to California after European contact and as a direct or indirect result of human activity.
Invasive species are defined as those that are not native yet can spread into wild ecosystems.  They displace native plant and animal species, can hybridize with the natives, and alter biological communities or processes.



Sticky Eupatorium, before

Sticky Eupatorium, Goin' Down

Enjoying a snack after the destruction.

    Invasive plants tend to crowd out native species in wild lands by creating monocultures that consume scarce water, nutrient resources or simply take up space.

Fountain Grass on rocky cliffs

Fountain Grass being escorted off 
the face of Rubio Falls

    Introduced invasives tend to spread fire quickly, and fuel higher fire temperatures, killing many native plants that might otherwise have survived. 
    With slow growing competitors and no native predators, invasive plants quickly find a foothold in our frequently disturbed wilderness.    
    Our native wildlife depends on native plants all the way up the food chain.  Non-native plants that naturalize and get along with the ecosystem are welcome, but those that invade and set up monoculture at the expense of everyone else will have to go.


The Non-Native Plants 
of Rubio Canyon

Sticky-Icky Eupatorium

    Native to Mexico, Sticky Eupatorium (Ageratina adenophora) invades coastal canyons from San Diego County north to Marin and has earned a place on the B list of Exotic Pest Plants of Greatest Ecological Concern of CalEPPC, a non-profit organization which deals with problem plants throughout the state. 
    Found growing in moist places with plenty of sun, it overtakes riparian habitats by sheer numbers, clogging and drying up seasonal streams, crowding out native perennials, shrubs and seedling trees.
    Sticky Eupatorium may have medicinal value, appearing in the pharmacopoeia of the padres and early Mexican settlers.  Its showy white flowers and ease of growth may have made it a garden selection.

Tree Tobacco

    Tree tobacco (Nicotiana glauca) was originally introduced from South America by the Spaniards. It blooms nearly year-round, pausing only in extended drought or in the coldest part of winter. It has been naturalized in waste and disturbed areas, stream beds and roadsides.
    Like many species of the Nightshade family, it is poisonous to ingest in any form.  Fortunately, it's generally unpalatable to livestock and wildlife, save for the nectar which the hummingbirds seem to love.
    This plant increases fuel loads and competes with natives for water, light, nutrients and space. Steadily improving habitat quality and expanding species diversity will probably limit the spread and numbers of this species.

Fountain Grass at Rubio Falls

    Fountain Grass (Pennisetum setaceum) has been introduced as an ornamental plant in the 1950’s and is widely used in residential and commercial landscaping. This African grass crowds out native species by  creating monocultures that consume scarce water and nutrient resources, and prevent
recovery of native plant populations. 
    Washes and roadsides are most vulnerable to infestations. However they can spread into undisturbed habitat, as well.
    Propagating itself by fertilized and unfertilized seeds, Fountain grass re-establishes soon after fire, when it can spread more quickly without competition. In contrast, bluff and scrub plant communities can take decades to reestablish following a fire.

(Technical supplement: Fountain grass can reproduce by either fertilized or unfertilized seeds (Simpson and Bashaw 1969, Dujardin and Hanna 1989).  The plants flower from July through October. Fountain grass is apomictic, meaning that it can reproduce asexually by producing seeds from the cells of female plants other than egg cells (Simpson and Bashaw 1969, Dujardin and Hanna 1989). It may also reproduce by seeds produced following pollination and subsequent fertilization of a female egg cell.  Seeds remain viable in the soil for at least seven years (Tunison et al. 1995).

We'd love to have you join us
for a few hours of stewardship
in Rubio Canyon!


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