The Morro Manzanita Chaparral Natural Community

The Morro Manzanita Chaparral Natural Community

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 image

Pixie cup

Coral fungus

Coral fungus

Manzanita flowers

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

Ethnobotany Notes: Catalina Cherry

What should I plant in my yard this fall before the rains begin? People are often asking me this. I like to consider what Doug Tallamy told us at the CNPS state conservation conference a couple of years ago about planting trees and shrubs that are foraging hubs for insects and birds. He mentioned several genera that fed lots of caterpillars, which in turn feed lots of birds.

cherryOne of these was the genus Prunus. You may recognize this as a fruit tree genus including cherries, apricots, plums, and peaches. It attracts butterflies, bees, and pollinating flies. One of my favorites is the Prunus lyonii, or Catalina cherry. It has beautiful green foliage, is drought tolerant, and according to Las Pilitas nursery, it tolerates clay soils well. It is closely related to the native shrub called Islay (Prunus ilicifolia). Islay was harvested for the kernels inside of the pit. Jan Timbrook notes in Chumash Ethnobotany that one hat of islay was worth two hats of acorns.

The kernel of the cherry needs to be removed from the pit (you may eat the thin skin of fruit in the process if it is ripe first). Then you must boil the kernels and rinse the water several times, then smash the kernels and then leach like acorns to remove the cyanide that naturally occurs in the kernels. Since the native Islay was not available at the time, I decided to try this with the Catalina cherry growing in my Mom’s yard. (Catalina cherry is used in the horticultural trade and can be bought and planted easily). I gathered the pits that had accumulated on the ground, cracked them open, boiled and leached the kernels, then made little balls out of them. They kind of tasted like cooked beans, bland but nutritious. My curiosity was satisfied. I’m not crazy about the kernels as food, but I love the shrub with its gorgeous bright green foliage. The pictures below are from Morro Bay State park where it was planted between the campsites.

As I am writing this, I am thinking about the fact that we have our annual native plant sale coming up on November 2. I have been planting the plants that I have written about over the last year in my own garden, and I hope that you find some that will be perfect for yours as well. I’ll see you there on November 2.

Cathy Chambers

CNPS Education Program

CNPS Education Program

our chapter had the opportunity to work with Bev Gingg and Learning Among the Oaks, a program that has been working to introduce young children to the oak woodland community at the Santa Margarita Ranch, and, more recently, at the Pismo Preserve

Centennial Development at Tejon Ranch

Centennial Development at Tejon Ranch

The LA County Board of Supervisors will consider whether or not to approve the proposed Centennial development next Tuesday, December 11.

Although this project is located in LA County, we believe this is an issue that impacts all of California, both in terms of our biodiversity and the precedent it sets for sprawl at the Wildland Urban Interface. Tejon Ranch is one of the most biodiverse areas of California, containing 14% of California’s native flora and a third of our native oaks. What’s more, it’s situated in a high fire hazard severity zone, putting future residents in harm’s way. We are advocating for the conservation of this land in its entirety.


In Memory of Bill Deneen

In Memory of Bill Deneen

Bill Deneen, long time CNPS member, Hoover Awardee, and champion of the Guadalupe-Nipomo Dunes died at the age of 93 in September. Bill taught biology at Santa Maria High School  for 25 years, during which time he became a passionate advocate for the environment. He worked with Kathleen Goddard Jones and others to keep a nuclear power plant from being built in the Nipomo Dunes, which he loved with a deep passion. Later he was arrested from ‘crossing the blue line’ at protests against the re-siting of the power plant at Diablo Canyon, earning him the title of ‘ecohooligan’ which he wore proudly for the rest of his life. In recent years he opposed the use of OHVs in the dunes, and was on the enemies list of the local OHV community. He founded an Environmental Award which he gave out to encourage conservation action, and in a touching moment in his failing last years was given his own award by his admirers. In a sort-of-goodbye party in 2015 held at the Dana Cultural Center, he received accolades from friends and family to notable politicians like then-Assemblyman Katcho Achadjian and Congresswoman Lois Capps. Capps called Bill a ‘national treasure’. Older members of the chapter will remember the many field trips he led into the dunes, and his fierce sense of humor. Bill… we will miss you… and thanks.

David Chipping

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…)


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South Central Coast Invasive Species Eradication Project


There is a weed removal initiative underway called the South Central Coast Invasive Species Eradication Project. Funded by the Wildlife Conservation Board and matching partners the $600K project joins CalIPC with multiple partners in a merged region of San Luis Obispo County and Santa Barbara County with help from the Weed Management Area of San Luis Obispo County. This effort is targeting weeds with a realistic chance of eradicating 95% of their populations in five years.

The weeds selected for removal include:

  • Limonium ramosissimum – Algerian sea lavender
  • Limonium duriusculum – European sea lavender
  • Elymus farctus ssp. boreali-atlantucus – Russian wheatgrass
  • Cirsium arvense – Canada thistle
  • Linaria dalmatica ssp. dalmatica – Dalmation toadflax

The sea lavenders are at threat to Cordlylanthus maritimus ssp. maritimus – salt marsh bird’s beak and Suaeda californica -California seablite. They have appeared along the boardwalk in Morro Bay State Park In the Guadalupe-Nipomo Dunes. Russian wheatgrass can take over areas that are habitat for Atriplex leucophylla – Saltbush, Beach-Bur, Red Sand-Verbena and Dunedelion.

The agencies eradicating the weeds will track their progress through CalWeedMapper that CalIPC arranged. Partners will meet annually to report on progress.

The Sargent Cypress Botanical Reserve: A Hammock Forest

The Sargent Cypress Botanical Reserve: A Hammock Forest

Author: WOODY FREY, Professor emeritus, OH Department, CalPoly, San Luis Obispo. This article was first published in Pacific Horticulture and is reprinted here with permission. Six miles north of San Luis Obispo, California, up a winding road off Highway 101 at an...
Common Milkweed (kotolo) Asclepias eriocarpus

Common Milkweed (kotolo) Asclepias eriocarpus

common milkweed-imageThe cover drawing and article for this issue of the OBISPOENSIS was written and drawn by Alice Meyer. She was a very active member (and first Hoover Award Recipient in the 1970 and 80’s. She is the one who named our newsletter, OBISPOENSIS, and served as its editor (and typist) for the many years. She is also responsible for setting up the first successful chapter plant sales as well as recruiting our current Plant Sale Chair. She didn’t restrict herself to CNPS. She was also active in the Morro Bay Audubon to which she submitted a number of articles entitled “MEET A NATIVE PLANT’. Below is one of those articles. It was chosen since milkweeds are so important in the conservation of the Monarch butterfly and is being encouraged as a garden plant. Members of this genus serve as the primary food source for Monarch butterfly larva. While eating the milkweed leaves, the larva incorporate the milkweed toxins into their bodies and its these milkweed toxins that protect the Monarch larva from most predators.

I do need to mention a taxonomic update. In her first paragraph Alice places the milkweeds in the taxonomic family, Asclepiadaceae. This was where it was placed up until the 1990’s. Today the two families of milky sapped species [milkweeds (Asclepias) and dogbanes (Apocynum)] have been combined into the single family, Apocynaceae. Milkweeds are primarily temperate in distribution while the dogbane relatives are primarily tropical. Classical taxonomic work always accepted these two families as very closely related. Modern taxonomic studies (including DNA work) have discover the relationships to be intertwined which required their unification into a single family. A number of these formally separated but closely related families have now been combined.

-Dirk Walters

MEET A NATIVE PLANT Asclepias eriocarpus

Milkweed is a perennial plant of the milkweed family (Asclepidiaceae) family. The species shown is common in the Coast Ranges, Sierra Foothills south to Coastal Southern California from 100 to 2000 ft. The species shown is Asclepias eriocarpa (as-KLEP-i-as aor-ee-CARP-a). Monarch butterflies lay their eggs on this plant. The plants are erect and sturdy from 18-36” tall, with leaves 3-4” long, in whorls of 3 or 4 leaves. These are covered with fine hairs, which make them look and feel like flannel. Stems and leaves contain a milky juice, a form of latex.

The clusters of flowers appear in May at the ends of stems between the leaves. The structure of the flowers is very unusual. The corolla is cut into 5 petals. These are turned down so the hide the calyx. The stamens stalks are joined into a tube and the five ‘hoods’ are attached to the base of the column; this is the ‘crown’ of corona, and in this species the crown is pink or purplish. It is actually the nectary of the flower. The flower and its stem is creamy white. In the center of the flower is a fleshy column or tube formed by the stalks of the stamens, capped by the stigma, hiding the two tubes of styles leading down to the ovaries.

The pollen in each anther-cell is a waxy mass of different anthers and adjacent masses of different anthers are attached to a cleft gland. This resembles tiny saddle-bags, clipped together, and if a bee catches her foot in the cleft she may pull out and fly away with two pollen masses to fertilize another flower. To do this, she must get her foot caught in the cleft of another flower.

The probabilities of a bee catching a foot in the cleft of two different flowers, first to collect the pollen sacs, then to deposit them in another flower is so remote that this is called ‘lottery pollination’. When a flower is pollinated its stem enlarges and the petals fall off. The calyx remains at the base of the downy seed pod which becomes 3 to 4” long and the remains of the hoods hang on to the tip of the pod for time. When the pod is ripe, and dry, it splits lengthwise, revealing neat rows of seeds, each with a parachute of fine hairs attached. As soon as the these hairs are dry, the seeds will fly away on the wind to be dispersed. Flowers that have not been pollinated along with their stems, wither and fall away.

-Alice G. Meyer