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Oakmead Herbarium: floral postcards

A walk with Herb Dengler by Yvonne Daley (Stanford May/June 1998)

For Dengler, it has been a lifelong gift . . . “It’s been my honor to know this ridge,” he says. “It really is something of a miracle, with all the growth all around us, that this special place is still here.”


1/26/2020 Winter walking along San Francisquito Creek

There are two gems, visited again and again by plant aficionados, along San Francisquito Creek, the Douglas Iris site and the Leopard lily site, the former is on an alluvial terrace and the latter on serpentinite. Not the time for a creek walk for most vascular plants, though bryophytes are flourishing including the California endemic Bestia longipes on sandstone outcrops. Prepare for spring and early summer visits by reading Toni Corelli's Some Plants growing on Trail 1 Serpentine and by browsing the Herbarium photo archive.

Now is the time to visit San Francisquito Creek on trails 1 and 2 in order to clearly observe two major threats to the native flora: French broom(Genista monspessulana) and Silver wattle (Acacia dealbata). Evergreen, these Old World woody plants are now in your face, dominating extensive sections of the north streambank. Most of the native creek vegetation is deciduous and currently without leaves. These include woody trees and shrubs such as Elderberry (Sambucus racemosa), Black walnut (Juglans hindsii), Willow (Salix lasiolepis), Bigleaf maple (Acer macrophyllum), Western burning bush (Euonymus occidentalis), Black cottonwood (Populus trichocarpa), American dogwood (Cornus sericea), Snowberry (Symphoricarpos albus laevigatus), White alder (Alnus rhombifolia), Califonia hazel (Corylus cornuta californica), Pacific ninebark (Physocarpus capitatus), Oceanspray (Holodiscus discolor), Western Virgin's bower (Clematis ligusticifolia); and herbaceous perennials such as Torrent sedge (Carex nudata), Wild licorice (Glycyrrhiza lepidota) and Durango root (Datisca glomerata). So enjoy the diversity while one still can, even without their foliage.

10/5/2019 Herbarium fieldwork

The group's fieldwork activity focuses on monitoring the Preserve's floristically-rich sites (many listed on our place-names page) as well as specific plants, typically those plants that are special status and/or locally rare on the Preserve, in the county or throughout the Santa Cruz Mountains bioregion. Some of these plants have not have been observed for many years; dissapearances and declines are listed on the Oakmead website). We also carry-out random transects and regular surveys--frequently retracing former Herb Dengler routes gleaned from his notebooks--covering most sectors of the Preserve. Some are repeated more than once annually such as creeks, marsh and lakeshore. Our activity is documented by georeferenced records in our photo archive, voucher specimens in the Oakmead Herbarium and online records in the Consortium of California Herbaria, and Calflora observations. One can join us for many of the outing from 2010 to the present via Alice Cumming's JRBP photo albums.

Examples of Herbarium observations this year:

  • Many-flowered brodiaea (Dichelostemma multiflorum). Currently known in the Santa Cruz Mountains bioregion from a very few plants at a single Jasper Ridge location; first reported by S.  Burnham in 1907. Jasper Ridge is at the plant's southern limit of distribution
  • California shield fern (Polystichum californicum).  Purported sterile hybrid whose ancestors in our region are the locally common Sword fern (P. munitum) and the less common Dudley's shield fern (P. dudleyi).  All three species were found growing within a few feet of one another.
  • Yellow monkey flower (Mimulus guttata), common monkey flower, has been segregated into into several new species of which the Preserve has two, the perennial Erythranthe guttata and annual Erythranthe microphylla.
  • Narrow boisduvalia (Epilobium torreyi). Not known to be present since 1981. Only two verified occurrences in the Santa Cruz Mountains in San Mateo and Santa Clara counties.
  • Spreading wood fern (Dryopteris expansa). Previously known only on the Preserve from a 1930 voucher specimen at Rancho Santa Ana Botanical Garden, Claremont.

Other notable observations and discoveries are mentioned in our floral postcard to affiliates dated 5/15/2019


A number of infrequently seen plants are in bloom this season. Near the top of the list of local rarity is the 5 cm tall Griffin's bellflowerCampanula griffinii, last documented in 2013, known only from Jasper Ridge in the Santa Cruz Mountains  bioregion. Another is California cottonrose, which had never before been reliably documented at the Preserve. In the California cottonrose photo are some seemingly dried-up grasses, the exceedingly locally rare native annual Sixweeks grass, Festuca octoflora. Jasper Ridge has a dependable population of the tiny annual native Scribner grassScribneria bolanderi, with 4 bioregion locations. Showier is Abrams' woolly star, also known from 4 locations in the bioriegion. Pigmy linanthusLeptosiphon pygmaeus, is only known from Jasper Ridge and the large and floristically rich Sierra Azul Preserve in the bioregion. These tiny plants, and many others, frequently find favorable habitat in scurry zones of different ecotones, and also at the sides of trails and roads where there is often limited competition but also limited disturbance.

May 18 was the annual ant survey and a reminder that ants, other insects and flowering plants represent a classic case of coevolution over the past 90 million years (give or take). Elaiosomes are seed appendages, stocked full of lipids and proteins; they attract ants and are believed to promote seed dispersal. Ants carry the seed to their nest and eat the elaiosomes.  This does not harm the seed, and may in some cases help with germination.  When systems co-evolve, we need to ask:  how did the interaction evolve, which came first, and what are the benefits to the participants?  Did plants develop elaiosomes to attract ants, or do elaisomes help with water intake and germination, and ants have learned to take advantage of the situation?  The answer may be be a bit of both.

Claytonia (Miners' lettuce) is a common and widespread genus in the family Montiaceae at Jasper Ridge whose seeds have elaiosome appendages.  When ripe, the seeds are expelled explosively, scattering them far and wide.  What role do ants play in supplementing dispersal for this common, well-known plant? 

Claytonia exigua ssp. exigua SLENDER CLAYTONIA 
Claytonia parviflora ssp. parviflora SMALL-FLOWERED CLAYTONIA 

How many plants grow here?

The Oakmead Herbarium online listing of native and naturalized plants currently includes 814 vascular plants and 77 bryophytes. These totals represent terminal aka minimum level taxa (species, subspecies, varieties) in The Jepson Manual 2 ed. and supplements. The vascular plant total is somewhat over 10% of the taxa treated by The Jepson Manual when adjusted for differing treatment of some hybrids and non-natives. Native taxa are currently 70% (572 of 814) of the vascular flora. The Herbarium has 6,000+ voucher sheets of all bryophytes and some 800+ vascular plants, some representing garden and agricultural waifs and other adventitious plants not included in the Preserve's "official" flora. We track almost 1000 plants in our database including a significant number of undocumented reports in addition to the major categories listed above, i.e., "native and naturalized" and "waifs (primarily ephemeral garden and agricultural escapes)". Native and naturalized vascular plants are based on the current Jepson Manual with some additional names as explained on our online plant list. (1) Also, the native and naturalized flora referenced above includes taxa -- estimated at 3-4% of total -- known only from historical vouchers or presumed to have disappeared in recent from the Preserve; see a partial list of species loss and declines  All such plants are annotated in the online plant list. Finally keep in mind that there are other and perhaps more significant measures of the richness of the Preserve's flora . . . read more

(1) Scientific names follow TJM2 and supplements; we also include plants and names not treated by TJM2 and supplements. Following the Marin Flora, 2nd ed, 2007: “We include here as naturalized species those that are established and have a true competitive status without cultivation whether the plant is aggressively spreading or seems only passively and locally established. . . . Experience has shown that the waifs of today may become the weeds of tomorrow". We also include named hybrids not given taxonomic status in TJM2, e.g., Elymus x hanseniiQuercus x jolonensis.

8/29/2019 Plant Blindness

Most state laws provide fewer and weaker protections for endangered plants than the Federal Endangered Species Act. Like the Federal act, most State laws provide no or minimal protection for endangered plants on private lands. Penalties for violation of state laws are usually minimal. Very few state laws require state agencies to consult on their projects that may damage endangered plants. Very few have provisions for the designation of critical habitat or a requirement to develop recovery plans. Nevertheless, all state laws designate an agency responsible for endangered plants and give the agency the job of developing a state list. The agency is usually responsible for public information, education, and conservation activities in partnership with other agencies, organizations, and individuals.

California is somewhat exceptional, in that CEQA requires review of not only all federal and state-listed rare and endangered plants, but also requires consideration of plants with unofficial listing status (e.g., CNPS listed taxa).  Most of the CNPS-ranked plants are not on state or federal lists.

Diane Renshaw

5/13/2013 The Preserve at 40 (Stanford Report) 

One of those questions, and a current focus of research of the preserve, is how to best go about successfully preserving nature, or what is known as intervention ecology. "When Jasper Ridge was formally designated as a preserve, there was good reason to believe that it was a self-sustaining environment, that natural processes would sustain the natural biodiversity, for example," said Chiariello. "That worked for a while, but it's now clear that with invasive species and other pressures that won't be a sustainable practice for the future." In 2004, a new strategic plan for Jasper Ridge revised the founding "do-not-interfere" policy and opened a case-by-case discussion on how to strategically tweak an existing ecosystem – either at the preserve or elsewhere – to put it back on a natural path. "We're really interested in restoration now, but to do this effectively we need to first know, for instance, how important it is that you seed an ecosystem with a critical species first so that it can take off on its own," Chiariello said. "We can begin to understand that with the Mimulus system." As research in the preserve has moved in these directions, the types of faculty and students who gravitate to the preserve have shifted as well.

11/6/2008 Quercus aff. berberridifolia (Q. dumosa misapplied)

There is a shrub occasional on the Ridge, 3-6 ft. tall, sometimes in groups of a few individuals, sometime single, usually on northern slopes 500-600 feet elevation. We have never observed acorns. The leaves are adaxially ± flat to wavy, ± shiny, green; abaxially pale green, margin mucro- or spine-toothed. We have occasioanlly noticed the adaxial leaf feature emphasized in Jepson II: "with minute appressed stellate hairs." Collections have been made, and some plants in the field are marked with green tape. Paul Heiple proposes these are hybrids.

Treatment in Jepson 2 by the late John Tucker

Q. berberidifolia Liebm. Shrub 1-3 m or ± tree > 3 m, evergreen. LF: 1.5-3 cm; petiole 2-4 mm; blade oblong, elliptic, or ± round, adaxially ± flat to wavy, ± shiny, green, abaxially with minute appressed stellate hairs, dull, pale green, tip gen rounded, margin mucro- or spine-toothed. FR: cup 12-20 mm wide, 5-10 mm deep, hemispheric to bowl-shaped, thick, scales tubercled; nut 10-30 mm, gen ovoid, tip obtuse to acute, shell glabrous inside; mature yr 1. Dry slopes, chaparral; 100-1800 m. KR, NCoR, CaRH, SNF, Teh, ScV (Sutter Buttes), CW, SW; Baja CA. Hybrids with Quercus durata, Quercus engelmannii, Quercus garryana (Quercus howellii J.M. Tucker), Quercus john-tuckeri, Quercus lobata.

Local references to Q. dumosa

  • Q. dumosa was reported by Cooper (1922, p.26) as a constituent of the climax chaparral association on Jasper Ridge. His research area was just south of the current southern boundary of the Preserve. Other oaks in this association were gold cup (Chrysolepis chrysophylla), leather (Q. durata), interior live (Q. wizlizenii). He notes that all are evergreen, Q. dumosa barely so. 
  • The Preserve's first plant list (Springer, 1935) doesn't list Q. dumosa. It does include Quercus sp., found in the chaparral.
  • Duncan Porter (1962) lists Q. dumosa and indicates that is was vouchered in the Dudley Herbaium (voucher # 100665). This voucher was later redetermined as Q. durata.
  • Dengler (1975) does not list Q. dumosa though he lists a number of hybrids [Q kellog x Q. wizlizenii (morehus); Q. agrifolia x Q. wizlizenii; Q. agrifolia x Q. kellog; Q. doug x Q. lobata; Q doug x Q. durata].
  • There are transcribed lecture notes of Mooney (1978-1979) Jasper Ridge Plant Communities [Lecture Notes], makes reference to seven oaks at JR and a specific example in the field of Q. dumosa.


Cooper, William. 1922. The broad-sclerophyll vegetation of California: an ecological study of chaparral and its related communities . Washington, D.C.: Carnegie Institution of Washington.
Dengler, H. 1975.  A List of Vascular Plants of Jasper Ridge Biological Preserve
Mooney, H. 1978-79. Jasper Ridge Plant Communities
Porter, D. 1962. The vascular plants of the Jasper Ridge Biological Experimental Area of Stanford. Dept. Biol. Sciences. Research Report no. 2.
Springer, M. 1935. A floristic and ecologic study of Jasper Ridge. Thesis. Leland Stanford Junior University.


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