An attractive member of the Asteraceae (Sunflower) family Senecio elegans is an erect annual herb, up to 1 ft. tall and to 1.5 ft. wide. It is native to Southern Africa and is distributed along coastal California. In northern San Luis Obispo County there are groups at San Simeon Point and at the other end of the county in the Guadalupe-Nipomo Dunes. Local CNPS members have located them in the Dunes as follows–1984: Hidden Willow Valley by Malcolm McLeod and Austin Griffiths; 1986: Kathleen Jones; 1990: south of Oso Flaco Lake by Lynne Dee Althouse and David Keil. Germinating following rainfall, leaves have blades which are deeply cut (pinnately lobed), into several toothed lobes and are sticky to the touch. The spectacular fuchsia colored, daisy-like inflorescence bears flower heads lined with black-tipped phyllaries (leaf-like plant part located just below a flower). They contain many (100+) deep yellowish disc florets at the center. Each has 13+ fuchsia colored ray florets. The flower heads turn into fluffy white seeds, ready for the wind to disperse the seeds. Senecio elegans is an escaped invasive weed where it spreads rapidly, displacing indigenous vegetation such as Dunedelion (Malacothrix incana). Control is achieved by pulling it before flowering. I’ve been able to easily pull many hundreds in the Dunes south of Oso Flaco.
In our November 2019 newsletter we discussed the Los Osos Habitat Conservation Plan, a plan prepared by the County of San Luis Obispo to address the impacts of development in Los Osos. In that plan there is a great deal of discussion of the Morro manzanita, Arctostaphylos morroensis, a plant that is listed by the U.S. Fish and Wildlife Service (USFWS) as Threatened under the authority of the federal Endangered Species Act. It is also a list 1B species, indicating rarity in California and elsewhere. What may not be as well known is that Morro manzanita is also the dominant vascular plant species of a rare natural community known as Morro manzanita chaparral, the Arctostaphylos morroensis Shrubland Alliance, as defined by the Manual of California Vegetation (Sawyer, Keeler-Wolf and Evens, 2009). This is an example of a natural community that is dominated by a listed species. Not all sensitive natural communities are.
Morro manzanita chaparral has a global ranking of G1 and a State ranking of S1, which is the highest (and rarest) ranking a natural community can have. Remember the Giant coreopsis scrub that we reviewed in our last newsletter? That community was G3, S3, also sensitive, but not as sensitive as the Morro manzanita chaparral, at least according to the California Department of Fish and Wildlife (CDFW) VegCAMP program. The Program and the CNPS Vegetation Program review the rankings, which are based on the NatureServe’s Heritage Methodology.
Morro manzanita chaparral occurs in three primary areas in the Los Osos/Montana de Oro area. It occurs north of town in the Elfin forest and northeast of the Middle School; south of town on the north-facing slopes above Highland and Rodman Drive; and in two large stands in Montana de Oro State Park. The Plant Communities committee of the SLO Chapter has sampled each of these areas using the Rapid Assessment techniques of the VegCAMP program, and we have found that in the 4 stands sampled, the cover of Morro manzanita varies from 23 to 85 percent, with the average being 53 percent. Other species occurring in these stands include chamise, wedge-leaved Ceanothus (Ceanothus cuneatus), and coast live oak. There are many other species, such as monkeyflower, black sage, and phlox-leaved bedstraw (Galium andrewsii), but they occur at very low cover values. The stands are almost impenetrable due to the low shrubby branches of the manzanita, and if it weren’t for already created trails in some of these areas, it would be difficult to walk through them. Two stands we sampled are located on north slopes; one on a south slope, and another on a fairly flat surface. On the Geologic Map of the San Luis Obispo-San Simeon Region (1979), all are shown to be on dune sands, but there are outcroppings of soft shales in the Cabrillo Heights area.
Many interesting mushrooms, bryophytes, and lichens occur in this community.
Pixie cup
Coral fungus
Manzanita flowers
One of my favorite lichens is the pixie-cup lichen (Cladonia sp., see photo), which can be found on the moist soils alongside the trails beneath and sometimes on the lower bark of the Morro manzanitas. There are several species in the area. One very rare species, Cladonia firma, occurs primarily in the coastal sage community just north of the Morro manzanita chaparral in the Morro Dunes Ecological Preserve, but it also filters into the chaparral in some areas where the two communities intermix as a mosaic. A unique mushroom I found two years ago in the stand south of Highland Drive is the coral mushroom (Ramaria sp., see photo). I almost felt as if I was underwater when I saw it! It was growing under the manzanita in colonies with other mushrooms.
Also occurring within this community is the Indian Knob mountainbalm (Eriodictyon altissimum), a species that is listed by the USFWS and the CDFW as Endangered. It is also a 1B species. This species occurs in only a few other areas in San Luis Obispo County, at Indian Knob near San Luis Obispo, and in Hazard Canyon at Montana de Oro. It appears to establish clones from rhizomes, and, like the Morro manzanita chaparral, is fire-dependent.
Morro manzanita chaparral is a very rare natural community that is seriously threatened. It’s location near Los Osos provides a unique habitat for contemplation, exercise, and enjoying nature. However, in some areas, it is being loved too much. Individual plants are being trimmed haphazardly by unofficial trail makers. Erosion of the very sandy soils is sometimes severe, creating extensive scars, exacerbated by foot and horse traffic. The issue of fire clearance to keep the public safe needs to be studied and addressed if it proves to be detrimental. And, although some populations are preserved, as always, we need to be ever vigilant of development being proposed within the area.
Photo Credits: Inside the Manzanita Canopy: David Chipping, Coral Fungus: Melissa Mooney, Morro Manzanita Flowers: David Chipping, Cladonia sp. Melissa Mooney
Two components of the Morro Manzanita Chaparral Natural Community. Left: Galium andrewsii; Right: Ceanothus cuneatus var. fascicularis Photos: David Chipping
Kieran Althaus joined our team last fall doing Social Media work along side Judi Young for the chapter. He is soon going to start his Masters Degree at Cal Poly in Biology with Dr. Matt Ritter and Dr. Jenn Yost. In the mean time he is staying occupied with the Plant Science Club at Cal Poly, as well as working on a variety of Botany projects.
This is a Call for Ecological Poetry/Prose/Art and Discourse throughout SLO County to unite with the cause initiated 50 years ago. Gathering stories to be Stewards of the Earth, this perspective can help direct hope for Earth, Forever.
If you have a venue or poem and would like an Earth Day Poem reach out to muebersax61@gmail.com Mary Uebersax, EarthTones Gifts, Gallery & Center for Healing 805-238-4413
My garden is small compared to the ones I manage in my horticulture business, but it’s still a hideaway for the birds, bees and native plants. It’s calming and is a source of tranquility for myself and my family. During difficult times, and I’m sure you have experienced them and know what I mean, the backyard can be a peaceful and serene place. Sometimes however, the garden can also create stress.
Gophers, spider mites and water bills, to name a few, can detract us from our beautiful garden. But keeping this in mind, we must remember we share this space with the critters and the insects. These are all part of the fabric of nature. Just like fertilizer and compost, gas and electricity bills, we have to budget for this special place. It doesn’t matter if it is a drought resistant native garden or even a cactus garden. There will be maintenance involved. Weeding can take us away from family and friends, however, I have found over the years, for me, the yard has been a great investment.
When I think about the hours of enjoyment I have experienced watching the birds, bees and plants in my garden grow, these times have been some of the best I ever had. So looking forward to the future and what it might hold, I’m hoping you will find that the investment of time, energy and money in your garden, is one that is well spent. Until next time, collect rain water and happy gardening.
Kieran Althaus joined our team last fall doing Social Media work along side Judi Young for the chapter. He is soon going to start his Masters Degree at Cal Poly in Biology with Dr. Matt Ritter and Dr. Jenn Yost. In the mean time he is staying occupied with the Plant Science Club at Cal Poly, as well as working on a variety of Botany projects.