CNPS Workshops and Professional Training

The Plant Science Training Program specializes in providing workshops for professional botanists, biologists, and ecologists to teach the skills and provide the tools and resources for conducting sound scientific surveys for rare plants, rare plant communities, vegetation, and wetlands. Discounted registration fees are offered to CNPS Members.

  • Mar 1-3 Vegetation Mapping Location: Redlands. Instructors: Julie Evens, John Menke, Todd Keeler-Wolf
  • April 4-6 Introduction to Plant Identification – Part II Location: Auburn. Instructor: Josie Crawford
  • Apr 18-20 Introduction to Plant Identification – Southern CA Location: Frazier Park & Tejon Ranch. Instructors: Nick Jensen
  • May 2-4 San Luis Obispo County Flora Location: San Luis Obispo County. Instructor: David Keil
  • May 17-19 Introduction to Plant Identification – Part I Location: Berkeley. Instructor: Josie Crawford
  • Jun 7-8 Rare Plant Survey Protocols Location: Redding, CA & Hog Lake, near Red Bluff, CA. Instructors: Heath Bartosh, Aaron Sims
  • Oct 3-5 Vegetation Rapid Assessment/Relevé Location: Bodega Bay. Instructors: Jennifer Buck-Diaz and Anne Klein
  • Date TBA Wetland/Riparian Plant Identification
  • Date TBA CEQA Impact Assessment


Hoover Herbarium Update Winter 2017

Thank you again to everyone who made 2016 a huge success in the herbarium. Here is some important info about the herbarium this quarter:

  • The times this quarter are Thursdays 3 – 5 pm and Fridays 12 – 2 pm.
  • I now have the ability to pay for metered parking so please let me know if you’d like to use that option.
  • Dr. Paul Wilson is guiding us on a moss collecting hike on Feb. 11th and will be talking with us in the herbarium on Feb 10th during the volunteer session.
  • Last quarter, we mounted almost 1,000 new specimens. That was really incredible and thank you to everyone who helped manage the large number of students who were in there!
  • We also finished cataloging the Herbarium Library, and boy did we find some treasures. We are still in the process of refiling all the books.
  • Cathy and Jason are making progress on our lichens and mosses.
  • The SLO Voucher Flora Project is still happening and we are chipping away at that. All of our records can be searched here:
    • Plants:
    • Mosses:
    • Lichens:

In other big news, our newest Botany faculty member, Dr. Dena Grossenbacher, has arrived to Cal Poly. She starts this quarter. She studies Mimulus and Clarkia, among other
wonderful plants. I’m sure you will all meet her at some point this quarter.

– Dr. Jen Yost

See also: Volunteer at the Hoover Herbarium

Volunteer at The Hoover Herbarium

Volunteer at The Hoover Herbarium

During the volunteer sessions at the Hoover Herbarium, people can take part in any number of activities. One of our primary responsibilities is mounting new specimens. This involves taking dried and pressed plants and glueing them to paper. When we mount plants, we do it in such a way that those specimens will last for hundreds of years. Each specimen is a physical record of what plants occurred where and when. Without this valuable information we wouldn’t know when a species goes extinct, expands or contracts its range, or where species occur. After mounting the specimens are databased and geo-referenced. Then they are filed into the main collection. We have over 80,000 specimens at the Hoover Herbarium.

herbarium plant sheet

A herbarium plant sheet, a important archive of our local flora

We are also working on a SLO Voucher Collection, which will contain one representative specimen for each species in the county. Volunteers look through our specimens and pick the one that should be added to the Voucher Collection.

Additionally, we are actively working on our moss and lichen collections. Volunteers can choose what aspects of the work they would like to participate in. Any and everyone is welcome.

The Hoover Herbarium is located on the 3rd floor of the Fisher Science Building (33) in rooms 352 and 359. Parking permits are required Monday through Thursday, 7:00 am through 10:00 pm; and Friday, 7:00 am through 5:00 pm. You can either buy a $6 day pass, a $4 3-hr pass, park in a metered space, or park off campus and walk in. I can pay for metered parking, but you’ll want to arrange that with me first.

Questions: email Jenn Yost at

– Dr. Jen Yost

See Also: Hoover Herbarium Update Winter 2017

CNPS-SLO Banquet 2017

CNPS-SLO Banquet 2017

California Native Plant Society – San Luis Obispo Chapter

Annual Potluck Banquet

Saturday, January 21, 2017

5:30-9:30 pm

$10 per person, plus a pot luck item for the dinner

Morro Bay Community Center

1001 Kennedy Way, Morro Bay

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Social Hour – 5:30 pm

Buffet Style Potluck Dinner – 6:30 pm

Chapter business – 7:30 pm

Program: “Rediscovering and conserving California’s prairie landscapes” – 8:00 pm

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Our banquet speaker this year will be Dr. Glen Holstein , Sacramento Chapter Botanist

Glen is Chapter Botanist for the Sacramento Valley Chapter of the California Native Plant Society. He’s a graduate of Cal Poly, San Luis Obispo, with a degree in biology, and from there to botany graduate school at UC Davis. Glen took a few years off to help found the California Natural Diversity Data Base, participate in creation of the Cosumnes, Cold Canyon, Nipomo Dunes, and Carrizo Plains reserves, and to write a chapter on riparian biogeography for Warner & Hendrix’s California Riparian Systems. Following that he finished his botany Ph.D. at Davis with a dissertation on climatic influences on plant physiognomy in world biomes.

As a botanist consultant he saw much of California and its rare plants. He has been a CNPS member continuously since soon after it was founded. Retirement has enabled him to devote much more time to CNPS as Botanist and Council Delegate for the Sacramento Valley Chapter while also serving on several allied conservation organization boards. One of his projects was guest-editing and writing three articles for the 2011 Fremontia issue on California’s prairies and grasslands.


Tickets are $10 per person – You may reserve your spot with credit card or PayPal by clicking the Tickets button, or if you prefer, you may send payment to D. Krause, 2706 Newton Drive, Cambria, CA, 93428. You may print this form to include with your check.
Questions? Contact David Krause  at or 805-927-5182



CNPS will be providing the beer, wine, coffee, tea, and assorted beverages included with the cost of the banquet. Plates, glasses, cups, and napkins will be available; we ask that you bring your own eating utensils, although plastic utensils will be available.

For the dinner potluck, we are asking those with last names beginning with the following letters to bring the suggested item (and serving utensils). However, if you have a dish you especially want to share with the group, please feel free to bring it or contact Lauren (805-460-6329, for alternative suggestions.

A to H: main meat or veggie dish
I to Q: salad (with dressing) or side dish
R to Z: dessert

Please put your name on a label or piece of tape on your serving items so they can be returned to you.


Exit Hwy 1 at Morro Bay Boulevard. At the “roundabout” turn right onto Quintana Road, and left onto Kennedy Way (after Albertson’s). Go ½ block. Community Center is on the right.

If you have any questions, please contact Lauren at, or 805-460-6329.

Hope to see you there!

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Facts about Oaks


Coast Live Oak (Quercus agrifolia)

IMAGE: By PeterOMalley (Own work) [CC BY-SA 3.0 ( or GFDL (], via Wikimedia Commons

The greatest girth of a single trunk coast live oak, measured at a height of between 1.3-1.5 m above the ground, is 30. 15 ft. (9.19 m), the tree being “The Grand Oak” at Highland Springs Resort in Cherry Valley, California.

The nemesis of the Coast live oak, as far as sudden oak death is concerned, is California Bay. The record for this tree is a girth of 30.51 ft. (9.3 m), located in the Rancho San Antonio Open Space in Palo Alto.

The Pechanga Great Oak Tree of Temecula is a Coast live oak that is probably the oldest oak in California and possibly the world, dated at about 2,000 years.

Canyon Live Oak is also impressive. The largest is in the San Bernadino Mountains and is 12.7 m in girth. This is also a species at great risk from Sudden Oak Death. although not in drier locations.

The tallest oak Valley Oak, a white oak which are not affected by Sudden Oak Death. The tallest specimen is in the Covelo Valley in Mendocino County, and stands at 140 feet (42.7 m).

The Field Guide to Plant Galls of California and Other Western States (by Ron Russo, U.C. Press) identifies more than 300 species of galls, including 95 found only on oaks. They are created by wasps.


IMAGE: By Alex Wild, part of the University of Texas at Austin’s “Insects Unlocked” project. [CC0], via Wikimedia Commons

Over 150 species of wasp are known to be associated with oak galls. However just one of these wasp species is associated with another 90 insect species that utilize the gall in some way.

Oak Gall

IMAGE: By Franco Folini from San Francisco, USA [CC BY-SA 2.0 (], via Wikimedia Commons

The round galls, called oak apples, on California Live Oak can be a source of fountain pen ink. Find out how to make it here.

Doug McCreary writes, in Living Among The Oaks, “Oak environments are among the richest wildlife habitats in the state; 110 species of birds use oak habitats during the breeding season, and 35 percent of California’s land mammals utilize oaks during
some time of their lives. California’s deer herds are particularly dependent on oak habitats.”

The oaks (Family Fagaceae, genus Quercus) belong to an old lineage of trees and shrubs that dates back to at least the Late Cretaceous (about 85 million years ago). The oldest fossils are most closely aligned with Fagus, the beeches, but there are also suggestions of chestnuts (Castanea) in some of these ancient materials. These fossils are known, to date, only from Georgia, in the south eastern United States. When it comes to the origin of the oaks (Quercus spp.), there is much better evidence. The fossil record reveals that trees similar to oaks first appear about 32-35 million years ago, and trees related to extant species appear by about 25 million years ago. By about 23 million years ago, trees representative of most major groups of oaks have appeared. Dr. Richard Jensen,Saint Mary’s College, Notre Dame, Indiana

The Juniper-Oak Plant Association of Caliente Mountain

The Juniper-Oak Plant Association of Caliente Mountain

Caliente Mountain is the highest spot in the County, and forms the western side of Carrizo Plain National Monument

The oak on Caliente Mountain. is Tucker’s oak, a scrub oak with blue-green, spiny leaves that stands a little over head height but can reach to 7 meters. Quercus john-tuckeri, as it is properly called, is named after John Tucker (1916-2008), Professor of Plant Science at U.C.Davis who also wrote the oak treatment in the Jepson Manual.

Hoover in his “Vascular Plants of San Luis Obispo County” called the oak Quercus dumosa var. turbinella, and  that, at that time, Tucker called the same tree Quercus turbinella sap. californica. Added to the confusion is known hybridization with blue oak, Quercus douglasii. The oak is mixed in with California juniper, Juniperus californica, and a mix of chaparral plants including chamise. This association of oak and juniper ca also be found in the uplands of the Great Basin and Arizona, although the species are different. This is part of the great “P-J”, the pinyon pine- juniper association that is very common in the uplands of the arid west.

The “P” of the “PJ” is rare in the Caliente Range, but much more common on the flanks to Mt. Pinos to the southeast. Both oak and juniper are present at the summit. The balance between them varies from place to place, with the junipers seeming to tolerate slightly drier sites than the oak.

You can visit this interesting plant association by driving up the dirt road toward Selby Campground, and branching to the right just before the campground. The road is drivable in a vehicle with normal clearance, but is narrow in places and has some steep drop-offs. During the droughty spring of 2016 there were still a lot of flowers to be found along the road, including a lot of wind poppies (Stylomecon heterophylla) and yellow sheets of Monolopia.

Oak’s companion on Caliente Mt. is the California juniper, Juniperus californica. It is here seen with its distinctive blue-grey berries. These are not true berries, but cones with merged fleshy scales. Berries are very bitter, and were/are used in the flavoring of gin. Gin’s name is derived from the French and Dutch word for juniper.

You don’t have to go all the way to the top of Caliente Mt., as there are large stands along Highway 58 between Navajo Creek and the Carrizo Plain. Another large stand lies on the north slope of the ridge that borders Highway 58 between La Panza Road and Shell Creek.

The stand near Shell Creek is an excellent example of the control of vegetation by slope aspect, as the south facing slope of the ridge is grass covered and has almost no trees. This can be seen as you drive east on Highway 58 toward La Panza Road.

-David Chipping

Iceplant (Carpobrotus edulis)

Iceplant (Carpobrotus edulis)

Invasive Species of the Month: Iceplant (Carpobrotus edulis)

Iceplant is a perennial in the Aizoaceae family, native to South Africa and grows in sandy areas on the coast from Eureka to Baja. This succulently leaved plant is overwhelming and carpets the land. I’ve seen outcompete giant Coreopsis and beach spectacle pod. Iceplant competes for nutrients, water, light and space. In very dry places they have long straggling woody stems. The pink or yellow flowers are beautiful and peak in early summer. The leaves root in the soil at the nodes and reproduces by seed. Seeds that passes through an animals gut germinates better.

Iceplant may be pulled and removed–which is the case at Piedras Blancas lighthouse, with spectacular results from the emerged native plant seedbank. Iceplant may be sprayed and the dead matter makes an excellent mulch for native plantings. Frost also kills Iceplant.

According to Cal-IPC iceplant was brought to California in the early 1900’s for stabilizing soil along railroad tracks. It was planted along freeways by Cal Trans until the 1970’s. Now it provides job security for weed warriors.

– Mark Skinner

Carpobrotus edulis or Carpobrotus chilense?

These two species are very similar, and the Jepson descriptions do not fully cover the overlap of features. Generally C. chilense has smaller magenta flowers (3-5 cm diameter) compared to 8-10 cm for C. edulis, which favors yellow flowers, but there is color ‘crossover’. The flower of C. edulis is pedicelled and C. chilense is sessile. The fruit of C. edulis is triangular in cross section, that of C. chilense more rounded and softer.

Carpobrotus edulis on earthquake-elevated mudflat, Shark Inlet, David Chipping

Carpobrotus edulis on earthquake-elevated mudflat, Shark Inlet, David Chipping

The photograph above shows a massive carpet of Carpobrotus at Shark Inlet. The bench in the foreground used to be pickleweed marsh until the Paso Robles earthquake caused the sand dunes to press down into the mudflat, squishing the edge of the flat above the high tide line and enabling the iceplant invasion.

– David Chipping

Fall Color

Fall Color

O.K…. so we’re not Vermont. However we do have some pretty fall color displays. If you like the gold of aspen, you will see the same colors in our closely related cottonwood stands, both trees belonging to the genus Populus. (more…)

Sudden Oak Death Enters SLO County

Sudden Oak Death Enters SLO County


The cover for this issue features four leaves of California Bay (Umbellularia californica) that show the tell-tale symptoms of infection with Sudden Oak Death disease, in the form of the fungus-like eukaryotic microorganism called Phytophthora ramorum, also known as a water mold. Photo by Doug Schmidt.

California Bay is the ‘Typhoid Mary’ for this disease as far as coast live oak is concerned, as the mold will massively replicate in the bay, raising the risk for infection in any nearby oaks. Once infected, the chance of an oak surviving is very low. Tanbark oak is a similar source of infectious spores, but is also essentially killed by the infection, unlike bay which will continue to live and be infectious.


The disease first showed up in the Bay Area and for several years had been spreading southward. The Sudden Oak Death (SOD) Blitz is citizen science based program that includes monitoring for any trees that have symptoms, concentrating on a search for symptomatic tanbark oak and California bay by volunteers. Volunteers record suspected infections and collect symptomatic leaves which are sent to a University of California lab for diagnosis. CNPS members participated in the SOD Blitz in 2013, 2014, 2015, and 2016, surveying hundreds of trees and collecting samples, and until this year our county showed no positive detections. The analyses of samples collected during the 2016 Blitz revealed a lot of infected bay trees, especially in the Santa Rosa creek areas east of Cambria, and extending as far south as the Irish Hills.


The infection generates oozing lesions behind the bark of an oak that cut off the transport of water in the tree. Death for oak tree may take as long as several years from the time of infection, but infection may not be visible until the tree dies (thus the name Sudden Oak Death). Tanbark oaks often succumb quickly, first manifesting wilting of leaves and branch ends. Other species such as rhododendrons and bay trees can be infected but may not be killed. Many other native tree and shrub species can be affected (more than 100 plant species have been shown to host the disease, although in some there are hardly any symptoms), but infectious spore production seems to be confined to bay and tanbark.


The Phytophthora group of organisms are water molds, and the reproductive spores require water for natural transmission. Water is vital to the species; the spore is motile, and can ‘swim’ in water.. Water remaining on the ends of leaves is where the spores germinate and become active. Water dropping off infected leaves or leaves dropping will carry spores to the ground or be carried by wind (especially during wet, windy weather), and it is rare that the infection will spread more than a few hundred feet unless the spores are picked up by animals or flowing water. The spores can remain in soils possibly for years.


The oak species known to be infected are Coast live oak, Canyon oak, Kellogg oak, and Shreve oak (all red oaks), and white oaks such as Blue oak and Valley oak are not infected. The symptoms may be hidden for a while after infection, as the bark of the tree will look healthy and the leaves will look normal or start to have die back at the ends of branches. Cankers are spreading under the bark, gradually pinching off water flow to the crown. Lesions may appear and drip a viscous burgundy liquid that becomes runny when wetted. The liquid smells like old wine barrels. Spores do not reproduce in the cankers and won’t be found in the dripping liquid, and so oaks are not thought to directly infect neighboring trees.


As the spores can be carried in leaves and in soil, soil and plant material from areas that might have the infection present should not be moved to areas with any plants know to host SOD. It might be wise to remove bay or tanbark trees if they are close to any red oaks and within reach’ of the disease. However both trees are a significant component of the local flora, and so removal should be considered only after deep thought and consultation with experts. It is also recommended that wood from dead oaks should not be moved close to uninfected oaks, and one should not export mulch from areas that have some probability of infection.


SOD has been present in California since the start of the century, and much has been learned. There are two excellent web resources for more information.

The California Oak Mortality Task Force ( is offers much information on the disease

UC Berkeley Forest Pathology and Myclogy Lab ( is the base for new detection and the SOD Blitzes. This site has downloadable SOD detection maps that can opened in Google Earth. The maps show the locations of all samples collected in the blitzes, and the indication of SOD presence.

SOD symptoms on Tanoak
Water a Milkweed, Kill a Monarch?

Water a Milkweed, Kill a Monarch?

Monarch caterpillar feeding on Asclepias fascicularis

All of our local native milkweeds are perennials, but like a lot of our drought-adapted plants, die back and go dormant during the long late summer and fall drought. Many gardeners, knowing there is a monarch butterfly/ milkweed connection, try to keep the milkweeds green all year, or use non-native milkweeds that stay green. Cal Poly’s Dr. Francis Villablanca has shown that winter breeding by monarchs will take place if green milkweed is available, which would not normally happen in the overwintering populations in SLO County. Nonstop breeding on the same plants can perpetuate the transmission of a devastating parasite called OE, for Ophryocystis elektroscirrha.

Normally, the transmission cycle is broken when milkweeds go dormant. The infection can kill adults as they emerge from their chrysalis, while mildly infected monarchs fly poorly, don’t reproduce normally, and die early. These very sick butterflies can then carry spores of the pathogen into the milkweeds in other gardens or along the entire migration route.

You don’t have to tear out a non-native milkweed if you cut it way back. While the infection issue is much greater for the central USA migration paths, it is critical that we take preventive actions on the coast, especially since we are still determining how bad it actually is in California.

Many thanks to Dr. Villablanca of Cal Poly on putting all of this together.

David Chipping