Download Invasive vs. Non-Native species People bring the

Invasive vs. Non-Native species
People bring the plants they love with them and sometimes even those they don't. Over
1,200 non-native species of plants have been brought into California however most of
those have "naturalized" without causing any real problems. In the forthcoming articles
we will look at plants that have not naturalized but rather become a problem for San
Bruno Mountain. We refer to these as invasive species.
To learn more about local invasive species you can pick up a copy of Protecting San
Bruno Mountain, a guide to conserving local flora and fauna. This pamphlet is
produced by the Open Space and Ecology Committee of the City of Brisbane and San
Bruno Mountain Watch, and is free thanks to the Arthur and Elena Court Nature Watch
Conservancy.
Local Invasive species to watch: Ox Eye Daisy (Leucanthemum vulgare) is a common
plant easily purchased at many garden centers. It is sometimes included in "wildflower"
mixes. The flowers are about 2" across and the plant grows from 1-3' tall. It is a
perennial so it is necessary to remove the root to prevent it from re-growing. The seeds
can remain viable for over 20 years making this plant very hard to eradicate. It harbors
potato virus and crowds out native plants wherever it becomes established.
There are over 15 daisies that are native to California, most of which are smaller and
make good ground cover.
Native alternatives to plant: Pacific Aster (Symphyotrichum chilense) and Seaside
Daisy (Erigeron glaucus)
Local invasive species to watch: Pincushion Plant (Scabiosa atropurpurea), also
known as Mourning Bride. Scabiosa is listed as an invasive plant in the US, Chili,
Australia and New Zealand. Its long blooming season (March-November) has made it a
favorite with gardeners for many years and in many parts of the world. A simple google
search will list dozens of retailers selling this plant. Its common name, the ‘Pincushion
plant’ comes from its egg shaped seed head with, prickly seeds sticking out like small
pins from a pin cushion. These seeds are easily transferred on hikers’ clothes and
animals’ fur, allowing the seeds to spread quickly along trails. It typically achieves a
height of 2’ but can grow 3’ high in favorable conditions. Where it becomes established,
it forms monolithic stands, crowding out native plants. Scabiosa is an annual and an
excellent cut flower, so pick the flowers when ever you see them and take them home to
enjoy in a vase. This will help to control the population on San Bruno Mountain.
Native alternatives to plant: California Mountain Lilac (Ceanothus concha) or
Cleveland’s Monkey Flower (Diplacus clevelandii)
Local invasive species to watch: Licorice Plant (Helichrysum petiolare) is a common
garden plant introduced in the 1960s and still sold by nurseries and major distributors.
Licorice plant has escaped into native habitat and become invasive, crowding out even
dense and healthy stands of native plants. It grows about 2' tall and spreads wide with
wooly grey-green evergreen leaves and yellow/white button like flowers in summer. It
produces a large amount of seeds and can root from the stem, spreading in clumps. The
leaves have a slight licorice odor but it should not be confused with the true licorice plant
(Glycyrrhiza glabra). Licorice plant is perennial, small plants can be pulled by hand.
Herbicides are not recommended. Licorice plant resembles native cudweed when
flowering, but is much larger.
Native Alternatives to plant: Coast purple sage (Salvia leucophylla) or Bush germander
(Teucrium fruticans)
Local invasive species to watch: Pampas grass (Cortaderia jubata andean) grass is fast
growing and spreads quickly along roads, cliffs, open spaces and river banks. Pampas
grass was introduced by nursery operators, and spread all over the state. Pampas grass is
hearty and can withstand a variety of weather conditions, living close to 10 years.
Millions of seeds produced by one stand can spread several miles away. The growth and
spread rate takes over landscapes and outcompetes native plants. Currently the central
coasts and south coasts are invaded.
Native Alternatives to plant: Giant Wildrye (Elymus condensatus)