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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
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Rubio Falls, Altadena, California,
circa 1920
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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.
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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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