Invasive Species: Narrow leaf iceplant

Invasive Species: Narrow leaf iceplant

INVASIVE SPECIES REPORT

Mark Skinner

Conicosia pugioniformis Narrow leaf iceplant

Conicosia is in the Aizoaceae family. It is a succulent perennial with a crowded basal rosette of smooth, bright green, upright, linear leaves. Clustered with the leaves are stems with brilliant yellow flowers. All this on top of a carrot like root. It’s capsule fruits are dry at maturity.

Conicosia is abundant on coastal dunes. It seems like nearly anywhere I travel in the back dunes from Oceano to Guadalupe—there they are—they’re so darn ubiquitous! Conicosia crowds out native plants and is a prolific seed producer.

Do not step on a plant with dried capsules: the seed will stick to the bottoms of your shoes! Due to a thick root it is hard to pull. If one snaps off the leaves on the soil surface it will grow back, therefore a shovel is best. Chemical control is best achieved by spraying a liquid mix containing 1.5% glyphosate 1.5% surfactant. It is best to spray before flowering. (We caution that the use of glycophosate is under legal challenge as a possible carcinogen.)

Exotic Species on the Central Coast

This month’s President’s notes will be divided into two parts, with the second part included in the November issue.

As someone who frequently hikes in our California landscape, I often ponder over the abundance and diversity of exotic species that have naturalized here, and how that came to pass, specifically during the past two centuries. This is not to say humans did not move plants around California prior to the arrival of Europeans, but historical records point to the introduction and, in some cases, rapid dispersal of non-native species in our state, as a post-European-arrival event. So, I set out to satisfy my curiosity, and in the process found some interesting facts.

How did so many non-native species find their way to California and how could they spread so quickly and in such large populations – was it intentional or by accident – by air, by water, by animal, by human, etc.? I reckon humans have had preferences for certain plant species since the beginning of time, thus altering the landscape to create a more desirable food supply. As North Americans, most of the plant species we consume are actually native to somewhere else, where simple domestication events started eons ago. However, as non-native plant species were carried to other continents during the last 500 years, adequate safeguards for their containment were apparently not well understood, and the botanical invasion we see today in California correctly had its origins in the not so distant past.

Here’s one example. I am astonished to see European fennel (Foeniculum vulgare) growing in such numbers in abandoned fields in my neighborhood. It is particularly thick along the railway right-of-way that bisects this vicinity. How did those plants get so well established here? One possible scenario could be – it’s originally from Greece, then traveled to Italy, then to Spain, to Mexico, and finally to California, where it was planted in the early gardens in this area, and then transported via the hooves of horses and on the wagons they pulled, later on the trains, trucks and tractors that worked and subdivided the land, and finally via the shoes, socks, and pockets of humans. I wonder if that is how it really occurred.

This hypothesis comes from observations I have made while hiking in some of the more remote areas of our county, where it can be hard to find exotic species that have become established. In most cases, the further one travels away from human civilization, the fewer number and variety of exotic plants are found. There are exceptions to this rule, especially where soil type and/or moisture do not afford these plants adequate resources for growth. Here are a couple of examples of what I have seen in recent years, illustrating to me how new species have potentially moved into our area.

On some of the hiking trails, one finds an introduced species growing right along the path, but rarely more than a few feet off the path. Torilis arvensis, known as hedge parsley, or “sock destroyer”, is a European native having seeds covered with tiny hooks, similar to Velcro. The plant grows within the range of most people’s socks, i.e., 1-2 feet tall. Socks pick up the seeds when the plant is shaken and then transport them to new locations along the side of the trial, thus engineering this unique dispersal pattern.

The other example concerns two species; Canadian horseweed, Erigeron canadensis, and Italian thistle, Carduus pycnocephalus. Both of these plants were uncommon in our county 15-20 years ago. Later, they began showing up along roadsides and even later spreading along the trail systems, to the point where they now dominate sizeable portions of our open spaces. Canadian horseweed, although native to North America, has become an “unwanted plant” in many places, common in disturbed areas in full sun, while Italian thistle does best in partial shade, especially under coast live oaks. Both are in the Asteraceae family and produce copious quantities of seeds. Using its pappus, a small parachute connected to one end of the seed, these species achieve phenomenal aerial dispersal potential, even from a single plant. Seeds move with the wind, easily get lodged in vehicles, horses’ hooves, people’s shoes, etc. Thus, these seeds first arrived along roadsides, then moved along the trails into our wildlands.

So, I guess the finger of blame for these introductions, and rapid disseminations, points to us, because the patterns of dispersal invariably involve human activity. Next month, I will cite some historical records to further illustrate my point.

Torilis. Photos by David Chipping

Carduus and Torilis, right) revealing two different seed dispersion strategies.

 


Into the Fall season

THE GARDEN CORNER

With the Fall season almost upon us it’s time to start planning on preparation for the Winter season. The most important item on the list is weed control. By applying mulch now you will save lot of labor in the future (next Spring & Summer).

Any forest product four (4) inches thick will stop weed growth, but it can also affect desirable plants from thriving if you don’t follow the rules. So start by checking and marking any California native plants, like Baccharis, Lupinus, or Eschscholzia californica, before spreading mulch. Once all desirable plants are plotted using marker flags or sticks, spread a thick layer of clean chips of any forest product four inches thick to suppress weed growth. Leave a one-foot space around desirable plants with no mulch. This will prevent trunk rot. While mulching is not always 100% effective for weed control, it can definitely help mitigate the majority of grass weeds.

Happy Gardening; John Nowak, Plant Sale co-Chairperson.

Conservation blog October 2018

CONSERVATION NOTES

We are still awaiting the Draft EIR for the Froom Ranch development at Highway 101 and Los Osos Valley Road. We are also watching very carefully the Trump Administration orders to BLM to examine the oil leasing potential of all of its holdings. This is not a problem for most BLM lands in the County, as most are situated on geology extremely unlikely to contain oil deposits.

The county has been extensively drilled over the last century, with most being dry holes, although there is some potential in northern Santa Barbara County, the Huasna area, and some lands adjoining the Carrizo Plain National Monument. We will address any new lease sales as they occur. There are no chances of Morro Rock being drilled, as some conservation organizations have suggested.

We are also following the Diablo Canyon Decommissioning Process very closely, and attended panel hearings.

Lastly, we are also following developments in the Sustained Groundwater Management Act regarding the protection of surface waters:

David Chipping

Where Have All the Flowers Gone?

Many visitors to the Carrizo Plain in 2018 were expecting to see the showy displays of wildflowers that earned the area the  “Superbloom” designation in 2017…but they came away disappointed. So where did all the wildflowers go? In a word:
underground. Most wildflowers in the Carrizo Plain and other arid lands around the world are annuals, a strategy in which the plants complete their life cycle in a single growing season and wait out the dry season as seeds. In the meantime, the seeds are stored in the soil not too far below the ground surface, in what is called the soil seed bank. Those seeds sprout and grow into recognizable plants when temperature and moisture conditions are just right and any additional barriers to germination are overcome.

Some perennial plants do grow on the Carrizo Plain and similar landscapes. This type of plant survives through one or more dry seasons as fleshy roots, bulbs, or similar structures—which also are underground. Among the perennials you can find on the Carrizo are blue dicks, larkspurs, and various wild onions. Even these plants may not show up every year, waiting until years of “normal” rainfall to push stems above ground and produce leaves and flowers.

Each type of annual plant needs a different combination of moisture and temperature to stimulate seed growth. Native
wildflowers (those that evolved in this region over thousands or millions of years) generally do best in years when abundant rain occurs during the cool months of mid-winter. Many native plants produce a cluster or “rosette” of leaves at ground level during the winter and do not send up a flower stalk until the weather begins to warm up in the spring.

The ubiquitous nonnative grasses—most of which evolved in the Mediterranean region of Europe—generally respond to warm fall rains. Some of the more familiar nonnative grasses are red brome, soft chess, foxtail barley, and wild oats. When this area receives early rainfall, the nonnative grasses get a head start on the native wildflowers and turn the hillsides green. By putting down roots early in the growing season, these annual grasses are able to capture and absorb any rain that falls, leaving too little available for the native wildflower seeds to grow or survive beyond the seedling stage. Thus, years when rains begin early while temperatures are still warm and rains come regularly throughout the fall and winter have been called “grass years.”

A different set of conditions is needed to produce the masses of native flowers known as “Superblooms.” These tend to occur in years with abundant winter rainfall that does not begin until the cooler months of late fall and follows several years of drought. Germination barriers can take several forms. Some plants produce chemicals in the seed coat (the outermost layer of the seed) that must be leached out by repeated wetting before the seeds can sprout. Others have such hard or thick-walled seed coats that mechanical action such as rubbing or grinding by soil particles is needed before water can penetrate. And still others—particularly those that grow in vernal pools—need to be immersed underwater for some time to allow fungi and other decay organisms to break down the seed coat. Many years—even 50 or more!—may pass before seeds of a given type of wildflower are ready to start growing again. For this reason, the endangered California jewelflower was thought to have disappeared from the Carrizo Plain entirely, until an observant biologist spotted it in the late 1980s.

In the driest years, annual plants may bloom when they are only an inch or two high, producing only one or a few flowers, and they may or may not live until the few seeds are mature. But because they do produce at least some seeds in most years, usually at least a few of those seeds are ready to grow each year. In the “off” years these small, scattered plants are hard to find, unlike the showy patches that can be seen from miles away in the wetter years. Luckily for visitors to Superblooms come along once every decade or so. We can only guess what type of year 2019 will be….

Ellen Cypher

Clarkia speciosa subsp. immaculata (Pismo Clarkia)

Clarkia speciosa subsp. immaculata (Pismo Clarkia)

Pismo Clarkia

Text by Dirk Walters; art by Mardi Niles.

I chose the Pismo clarkia because it grows in the area surrounding Mardi’s home and nowhere else. It grows naturally in about 20 occurrences from the southern Edna Valley, south through the foothills and valleys of the Southern San Luis Range, ending east of Pismo Beach and Arroyo Grande (Huasna Valley). (more…)

Why Grow Natives from Seeds?

by Marti Rutherford

You have probably wandered the nursery isles looking for the ever more popular native plants being sold. Do you ever consider how those plants have been propagated? Many, if not most, native plants in the nursery trade are propagated by cuttings. The nursery person knows what the plant will look like and behave like. And (more…)

Five Morros Field Trip

Five Morros Field Trip

Saturday, June 23

Five of the Morros of San Luis Obispo County

Join us for a day on the Morros and learn which plants grow on each of these volcanic plugs.  Ascend one, two, or more. Here are the start times. (more…)

Spring Wildflowers in Northern Santa Barbara County

Charlie Blair: Chapter Northern Santa Barbara County Liason

2018 has been a surprisingly good year for spring wildflowers. Except for the January deluge and some good March storms, this has been a fairly dry year. In late September, 2017, several spot fires burned along Rucker Rd. just north of Mission Hills near Lompoc, California. In spite of sparse rainfall, there has been encouraging (more…)

Seed Exchange

Seed Exchange

I know it seems too early to be thinking seeds. Many of my plants are just starting to bloom. I just wanted to remind those who are interested that the seed exchange is going to take place ate the October meeting before the main program. Let a few of your garden native plants go to seed and bring the seed to the seed exchange. More information will follow in newsletters to come. There is information on seed collection available on the cnpsslo website under the resources/growing natives tab (link). Marti Rutherford

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