Click on the thumbnails to see larger images.
December 2012 Marin Plant of the month by Doreen Smith:
Quercus durata, Leather oak
Photos by Vernon and Doreen Smith
Leather oak, Quercus durata, is common and nearly always found on serpentine-derived soils. In Marin this scrub oak grows in the chaparral of Mt. Tamalpais, Big Rock Ridge and Mt. Burdell.
"Our other scrub oak, Quercus berberidifolia, is very uncommon here, not on serpentine, and only easily discovered near Gold Grade fire-road halfway up the San Pedro Mountain behind Dominican University, San Rafael.
October - November 2012 Marin Plant of the month by Doreen Smith:
Astragalus nuttallii, Ocean bluff milk-vetch
( CNPS Inventory rating "4.2" a watch list of plants not presently thought threatened or endangered )
Photos by Doreen Smith
This was one of our County's rare plants that took me years to find. The single sprawling individual I've ever discovered is still present (Aug. 2012) on the steep cliifs of the S. end of McClures Beach, Pt. Reyes National Seashore about 20 feet above the highest tideline. The white flowers are most usually seen in June but a few may still be evident later in the year. Most noticeable at this time of year are the inflated pods.
Questions remain as to which variety this is. Jepson 2 calls this occurrence A. nuttalli var. nuttallii while Marin Flora 2 calls it var. virgatus. Frankly I think the distinction in the Jepson key to the two A. nuttallii varieties is inconsequential i.e. presence or absence of many versus only a few hairs on the backs of the leaves.
Someone reading this may know of other Marin occurrences, if so please let me know.
Plans are afoot that the persons answering the recent questionaire that they were "interested in rare plants" will be asked to select an area of the County to monitor and then report their findings back to me. Some outings will be announced in the Spring to monitor some of the Marin rare plant populations.
August-September 2012 Marin Plant of the month by Doreen Smith:
Sagina maxima ssp. crassicaulis, thick-stemmed pearlwort
Photo by Doreen Smith
At this time of year those in search of native wildflowers in Marin are lucky we live on the Pacific coast where the cool climate enables an impressive number of species to survive and flower well into Fall.
Thick-stemmed pearlwort is small perennial that may be a rare species or just overlooked, poorly collected because it is so small and apparently insignificant. The plants occupy seeps on cliffs and upper parts of sandy beaches only in a narrow coastal strip, mostly North of San Francisco Bay. Southern California records are all old and it may already be extirpated there. The State CNPS rare plant science group led by Aaron Sims is now doing research to check if it deserves LIST 4 status i.e. a watchlist of plants of limited distribution.
To see the species in Marin is easy, it grows where freshwater seeps emerge from the bluffs at McClures Beach and into the upper parts of the sandy beaches there. Another population is on the path to the Lighthouse from the parking lot, growing with orange Trentepohlia, under a N-facing cliff-face. Fog drips from overhanging Monterey Cypress keep the site moist all year.
July 2012 Marin Plant of the month by Doreen Smith:
Clarkia amoena ssp.huntiana, Farewell-to-spring godetia
Photos by Doreen Smith
The genus is named in honor of William Clark of the Lewis and Clark Corps of Discovery first transcontinental U.S. expedition,1804-1806.None of our seven Marin native Clarkia species, more if you count the subspecies, have been very abundant this year, probably because of the dry winter. Best and most abundant shows of these flowers occur when warm Fall and Winter rains enable annuals to put on early vegetative growth.
The best place in Marin County to see the northern, inland subspecies, Clarkia amoena ssp. huntiana, has traditionally been along Lucas Valley Road near the Big Rock, and some are still there (I hope).
Unfortunately not everyone appreciates these showy pink wildflowers, the roadside banks there have been severely clear-cut to the ground near the Loma Alta trailhead . Not only the Clarkias but several other native species of serpentine grassland were scalped there while in full bloom in early June. I hope there is a chance that some of these ever-diminishing wildflowers will survive, despite the more than usually-extreme level of roadside maintenance this year."
June 2012 Marin Plant of the month by Doreen Smith:
Our native marsh mint, Mentha canadensis
Photo by Vernon Smith
Marin County has only one native species of true mint, Mentha canadensis, which grows mostly on Pt. Reyes in this County. Previously it was thought to be a variety of M. arvensis until the Jepson Manual # 2 revision of the genus by Arthur O. Tucker. This plant grows in freshwater marshes and is apparently common and widely distributed in California.
Photo by Vernon Smith
Mentha aquatica is found in even wetter marshes, usually growing in standing water. Introduced from Europe, it is especially common by the Kehoe Beach trail on Pt. Reyes, in the marsh with the giant tules. Previous to the latest revision, it was listed in the Marin Flora as Mentha X piperita. Mentha pulegium, an invasive weed, is the most common mint in Marin, found growing wild in ditches and seasonal wetlands.
All three of the above mints have been used either presently or historically in food or folk medicine. Other garden-escape Mentha species and hybrids like peppermint and spearmint are occasionally found in the wild, usually in moist places.
May 2012 Marin Plant of the month by Doreen Smith:
Ceanothus masonii and some of its close relatives....
Photos by Doreen and Vernon Smith
Ceanothus masonii is a rare Marin County endemic shrub, probably confined to the middle part of Bolinas Ridge. It grows in chaparral on rocky, sandstone-derived soils with various other species of Ceanothus and 3 species of Arctostaphylos.
I was first introduced to this plant in the early 1990's by Robert Allen, then our Chapter's rare plant expert. We parked our cars at the junction of Ridgecrest and the highest point of the Bolinas to Fairfax Road. Then we hiked northwards through the coast redwood forest until we reached the open chaparral. Soon we found just a few shrubs of a short, stiff, holly-leaved blue-blossom, "real" Ceanothus masonii, growing by the shoulders of the fire road.
Advancing more to the north, past several specimens of the similarly rare Marin manzanita, Arctostaphylos virgata, we came across taller, larger-leaved, blue-blossom shrubs, these are the rare Ceanothus gloriosus var exaltatus. The point at which the two taxa met was indistinct, they merged gradually into each other.
The theoretical origin of Ceanothus masonii is that it is a stable hybrid of Ceanothus cuneatus and C. gloriosus var. exaltatus, however it may be just a variety of C. gloriosus. More study is needed.
"This is not the only puzzle about defining the taxon "C. masonii". In several parts of Mt. Tamalpais and its north-trending ridges are blue-blossoms which are probably hybrids of C. cuneatus and C. jepsonii. They grow in chaparral at junctions of sandstone and serpentine rocks. They have been erroneously called C. rigidus or C. masonii on some herbarium voucher sheets. Who says identifying plants is easy as long as you key them out carefully? Maybe yes, but often no. A plant may key out "perfectly" but still not be "it".
March 2012 Marin Plant of the month by Doreen Smith: Aristolochia californica, Pipevine:
Aristolochia californica has been recognized as a descendant from a group of the most primitive of dicotyledons, the Magnoliids, that existed before the splitting off of the ancestral monocotyledons. Other Ca. plant families in this group are Calycanthaceae, (Spicebush/Wild Ginger Family), Lauraceae (Bay-laurel Family) and Saururaceae (Anemopsis / Lizard-tail/Yerba Mansa Family). They are distinguished by having their floral parts arranged in 3s or spirally and having pollen grains with only one aperture. Many included genera have ethereal oils, are scented and used in folk medicine.
Along Lucas Valley Road the usual patch of green-flowered pipevine, Aristolochia californica, is flowering abundantly in the poison-oak brush. The site is in the flatlands, off by the S. side of the road, just past the historic farmhouse. A wide pull-out is there for any visitors (beware of possible ticks) just before a (blind) bend in the road. Lucas Valley Road is good for wildflower viewing most of the year."
Download plant list for Lucas Valley Road.
February 2012 Marin Plant of the month by Doreen Smith
Lomatium dasycarpum ssp. dasycarpum
hog fennel or biscuit root:
Photos by Vernon Smith. Click on images for full photos
In Marin this is a very common early wildflower that we may take for granted as it seems to grow just about anywhere . It can be found mostly in rocky areas of native grassland - such as on the S. end of the Chimney Rock peninsula and on the Tiburon peninsula serpentines.
This specimen was photographed Jan 11th, 2012 on the igneous dacite rocks above San Andreas Drive Open Space trailhead on Mt. Burdell, Novato.
However if you study different plants from different areas of the County there is lot of variation from the "typical" forma as pictured above that has very hairy petals and, later in the year, round hairy fruits. There are individual plants with hairless petals and only slightly hairy fruits that seem to approach Lomatium macrocarpum, or even Lomatium utriculatum, even when there are no individuals of those taxa nearby.
January 2012 Marin Plant of the month by Doreen Smith
Christmas berry or Toyon; Heteromeles arbutifolia
Photos by Doreen Smith Click on images for full photos
This common shrub in the Rose Family is considered the only member of its genus. It is a large evergreen bush or small tree which has clusters of white flowers in the summer and masses of red berries maturing in the winter. Distributed widely in California, from Humboldt County to Baja, it was used traditionally to decorate homes for the holidays. In fact the colorful branches with holly-like evergreen leaves and red berries became so popular it was recklessly cut in many places. Now it is illegal to take any on public land but you can grow your own from seed or cuttings.
Several plants are thought to be the reason for the name "Hollywood" and this is the most likely candidate. Coast live oak does have holly-like leaves but never any red berries.
December 2011 Marin Plant of the month by Doreen Smith
Poison-oak, Toxicodendron diversilobum, a shrub of the Sumac family, Anacardiaceae.
Photos by Vernon Smith.
If you are you looking for bright Fall color in our wildlands the poison-oak is magnificently clothed in red at this time of year. Of course the whole shrub is still very allergenic, no-one who has any sense ever gathers the leaves for decorations. The berries make nutritious snacks for birds: the fruits are relatives of the mango, pistachio and cashew nuts.
September 2011 Marin Plants of the month by Doreen Smith
Two Common Tarplants and One Rare One
The most common yellow-flowered tarplant in Marin, Hemizonia congesta ssp. lutescens, is still abundant along Lucas Valley Road and by the Big Rock to Loma Alta trailhead. The plants start to bloom in May and can continue until late Fall.
Originally taxonomists thought the type of H. congesta ssp. congesta was this yellow species but now consider the white-flowered plants of the Tomales area to be the real (and rare) thing. Therefore those are no longer being recognized as "Hemizonia congesta ssp. leucocephala" but as H. congesta ssp. congesta.
Also common at the Big Rock is Madia elegans which comes with both all-yellow flower-heads and a forma with red bases to the rays. Tarplants are very glandular, aromatic and resinous; this helps them conserve moisture and evade the attentions of herbivorous animals. Both species close up their flowers in the afternoon and don't open them again until the early morning.
August 2011 Marin Plants of the month by Doreen Smith
The Marin members of the genus Calycadenia (Kal-ee-ka-dee-nee-ah) a.k.a. tack-stem or rosin-weed because the tack-shaped glands on the floral parts make them resinous and sticky to the touch. These plants are late flowering annuals in the family Asteraceae (Aster-ay-see-ee) with a non-daisy-like flower heads. They have been known to confuse those attempting to identify them from others in the Tarplant group.
Two species are definitely still to be seen in Marin, especially the more common white-flowered C. multiglandulosa which grows abundantly on the serpentine rocky barrens in Tiburon, Mt. Tamalpais and Big Rock Ridge. The other white-flowered species, C. fremontii, has not been seen for many years or at least no reports have been filed.
The yellow-flowered species, Calycadenia truncata, is so far known to Marin from only a few plants from the top of Mt. Burdell where they are growing on igneous rocky sites. This species of Calycadenia is more common in other Ca. Counties.
June 2011: Marin Plants of the month by Doreen Smith
Clarkia species in Marin County
June is the peak time of year for seeing our local the "farewell-to spring" or "summer's darling" flowers,the Clarkias. I refuse to call them "fairy-fans". Often each species can occur en masse on slopes and in fields, especially but not exclusively on serpentine outcrops. We have several species but here I'll concentrate on the large-flowered sorts most commonly found.
Marin is at the junction of populations of two large-flowered godetia-form Clarkia species. Clarkia rubicunda with a central red zone to the corolla grows mainly south of San Rafael and into the S. Bay counties. C. amoena with the red-marks in the middle of each petal is found to the north as far as Oregon.
Ring Mountain and the Tiburon Peninsula have the most spectacular forms of C. rubicunda but they also occur in Tennesee Valley, coastally along Highway 1 near Steep Ravine and at Palomarin in the rocky canyon just before the lily-ponds.
Clarkia amoena in Marin has two subspecies: the ssp. amoena is the largely coastal one from Pt. Reyes and the Tomales area. The inland ones, like those near the Big Rock on Lucas Valley Road, are ssp. huntiana. Both these species have an erect inflorescence when in bud.
Should you find an apparently identical flower but the buds are drooping you have Clarkia gracilis ssp. sonomensis. This occurs usually on serpentine e.g. on Mt. Burdell near the rock walls N. W. of Van Note meadow, along Nicasio Valley Road north of Roy's Redwoods, and roadside on the S.W. part of Chileno Valley.
Just to be confusing some populations of both C. amoena and C. rubicunda have individuals or whole populations with most of the flowers without any red spots at all on the petals. Such plants can be discovered around Lake Lagunitas and along Sir Francis Drake Highway near Samuel P. Taylor State Park.
Can you work out which species they are.
May 2011 Native Plant of the month by Doreen Smith
Navarretia species in Marin County
"The Phlox family, Polemoniaceae, includes several Navarretia species in Marin. Some of them are common Ca. natives, three are listed rare. See P. 319 of the new edition of Howell's Marin Flora for more details than are presented here.
"We have nine species of Navarretia that can definitely be said to grow in Marin and one doubtful record. The doubtful occurrence is N. tagetina, which has a pale blue flowers and is perhaps to be found on the upper parts of Mt. Tamalpais, growing mixed in with the similar, but white-flowered, N. intertexta. If you happen to find it let us know.
Navarretia pubescens, Navarretia cotulifolia, and Navarretia leucocephala ssp. bakeri - click on images for full photo
"Most of these little herbaceous plants flower in late spring to early summer. The earliest to bloom is N. pubescens. It's known from Mt. Burdell and wasn't in the original Marin Flora because the locations were on private ranchland, off limits to Mr. Howell before they became to be County Open Space. Two other species are also only on Mt. Burdell in this County. These are the May-flowering very small population of N. cotulifolia and the larger vernal-pool population of N. leucocephala var. bakeri.
Navarretia mellita, Navarretia heterodoxa, and Navarretia intertexta - click on images for full photo
On Mt. Tamalpais, its northern ridges and meadows as far as San Geronimo, grow N. rosulata, N. mellita, N. heterodoxa , N. viscidula and N. intertexta. Finally the commonest and most noticeable species, N. squarrosa, skunkweed, is almost everywhere. It is the only Navarretia on Pt. Reyes.
April 2011 Native Plant of the month by Doreen Smith
Tiburon paintbrush, Castilleja affinis ssp. neglecta
This serpentine-endemic paintbrush was originally thought to be restricted to grassland slopes in three locations on the the Tiburon peninsula. Since then one other Marin location has been located on the GGNRA preserve on the Nicasio Highlands. Other counties have been found to have populations too, Coyote Ridge, Santa Clara County and above American Canyon,in Napa County. There is some variation in the color of the flowers and foliage. On the Tiburon Peninsula the leaves are green and the flowers cream to yellow, fading pink. The Nicasio Ridge plants have pale yellow flowers and purple foliage, they are growing in Ceanothus chaparral. A visit to this location is maybe possible this year for volunteers who help monitor local rarities with Michael Chass√©.
The Tiburon Old St. Hilary's and Gilmartin Preserve plants are threatened by off-trail bicycles, trampling, weedy grasses and French broom. We should be concerned lest this iconic plant disappear from ...our neglect.
March 2011 "Showy Weed" of the month by Doreen Smith
Harlequin flower, Sparaxis tricolor
Every year someone contacts us about the identification of this showy weed, fortunately or more likely unfortunately, it's common in Marin. It is a perennial from South Africa in the Iris family that grows from a crocus-like corm. The color-form pictured is the most usual - a large, stunning, bright orange-red flower with black and yellow markings. If you "Google" the Latin name other colors are shown there. The best (worst?) place to see multiple plants and different color-forms is the Bobcat Fire-road Trail up from Rodeo Lagoon in the Marin Headlands. There are lots of native flowering plants along this trail as a consolation prize for putting up with the several S. African species there, including Arctotheca prostrata, perennial capeweed, blamed upon "Klaus" a rogue planter of such things. This trail also leads to marvelous views of the ocean from the top of the hill.
The other common showy weedy wildflower from S.Africa is "pink crocus", Romulea rosea, it's also in the Iridaceae and similarly it will spread vegetatively from budding corms. Most often it is taken to be some rare Brodiaea.
December 2010 Plant of the month by Doreen Smith
Pt. Reyes bear-berry, Arctostaphylos uva-ursi
Bear-berry, Arctostaphylos uva-ursi, occurs in several widely-separated populations on Pt. Reyes Peninsula. Usually these populations are found growing in rocky areas, the smooth mahogany-barked branches with glossy green leaves sprawl over the ground. This is a useful habit and the handsome shrub is sold as a ground cover for gardens - not only to the native plant enthusiast. It is widely distributed, mostly in the Northern Hemisphere i.e. it's a circumboreal plant species. Local variants are often distinctive, for example in our Marin coastal form, the pink flowers are produced in spring, the red berries in fall."
October/November 2010 Plants of the month by Doreen Smith
Fall-flowering Marin spp. of Grindelia
Grindelia camporum: Central Valley gumplant
Where this species of Grindelia occurs in Marin is usually near an old road-construction site probably introduced by dirty, heavy-equipment from the Valley. It is uncommon here, much later to start flowering than our other species. The whole plant is sticky-resinous to the touch and the stems are whitish as if varnished, the leaves are almost holly-like. These photos were taken roadside on the way to the Las Gallinas wastewater ponds (so good for water-fowl watching) north of San Rafael.
Grindelia stricta var. angustifolia: bayshore gumplant
This name is appropriate for our common, shrubby, narrow-leaved North Bay gumplant. It is typically seen along the margins of tidal channels in the saltmarshes, such as at China Camp State Park. Plants are tall, perennially-green and can be found flower at almost any time of the year, though mostly in late summer and early fall.
Click on the images above for more Grindelia photos
For some time now the genus Hemizonia has been split into other genera - including this month's featured plants the spikeweeds, Centromadia spp. Marin has two species of these that have been around for years. It is likely they were originally introduced from other California sites by dirty, heavy earth-moving equipment used in major projects such as the re-structuring of the Lucas Valley Road /Highway 101/ Smith Ranch Road interchange and the construction of the Indian Valley Colleges.
The hairy one with the larger-flowerheads is Centromadia fitchii, picture from Lucas Valley Road at Mt. Shasta Drive: the smaller-headed nearly glabrous sort is C. pungens from grassland near the park-and-ride east of Highway 101 at Smith Ranch Road. C.fitchii is much more glandular than C. pungens and is more aromatic.
July - August 2010 Plant of the month by Doreen Smith - Piperia elegans ssp. decurtata
Most species of Marin's native orchids are summer-flowering. The rarest of all is the endemic-to-Pt. Reyes rein orchid, Piperia elegans ssp. decurtata. It grows only near the Lighthouse and about the Chimney Rock areas. The common P. elegans ssp. elegans is also found on Pt. Reyes but only on the eastern hills e.g. about Drakes Estero and Abbotts' Lagoon.
"Apart from the centers of distribution, which are at least about 10 miles from each other, the plants' flowers can be told apart by the differing lengths of the nectar-spurs. P. elegans ssp. decurtata has a much shorter one than ssp. elegans. It's perfume is different too, being likened to clove redhots rather than a sort-of almond library-paste odor for the common subspecies.
"A project is proposed to improve the waste-water sewage system of the Chief's House near the Chimney Rock trailhead. Unfortunately the only suitable well-drained soil for a leachfield is in coastal prairie about 100 yards to the S. of the house (and it's "historic" Kikuyu grass lawns). In previous years, the orchids, as well as other local plant rarities, have been seen blooming there. It is hard to find this orchid except when it flowers. We hope to take a monitoring field trip there in August to see if we can find this rare Piperia before any excavation work takes place.
Update from Doreen 30 July: "Piperia elegans ssp. decurtata are late this year and only just opening their flowers. Several spikes can be found both near the Lighthouse parking lot N. overlook and the Chimney Rock area Fish-Docks access road.
June 2010 Plants of the month by Doreen Smith
The bristly jewelflowers, Streptanthus glandulosus complex, the lumpers have it !
All Marin specimens of Streptanthus (except S. batrachopus) are now going to be put into subspecies of Streptanthus glandulosus, even S. niger. The variation in the form and color of the leaves and flowers from different populations is extensive and not all professional taxonomists who specialize in the genus agree with this latest treatment for the new edition of the Jepson Manual.
"Recently re-discovered is the population of Streptanthus glandulosus on the Ignacio side of Big Rock Ridge near the end of Fairway Drive that some have determined to be ssp. pulchellus, others ssp. secundus. Anyway it is a very fine form of the plant.
Another anomalous population is on the top of Nicasio Ridge on serpentine, it seems to have features in common with the Santa Clara population of S. glandulosus ssp. peramoenus. "
May 2010 Plants of the month by Doreen Smith
Castilleja rubicundula ssp. lithospermoides
vs. Castilleja ambigua ssp. ambigua
vs. Castilleja exserta ssp. latifolia
vs. Triphysaria versicolor ssp. versicolor
The first thing to do in determining the differences is to separate the genus Castilleja from Triphysaria. This is done by examining the stamens with at least a 10X loupe. In the Triphysaria spp. each stamen has one anther sac, in Castilleja each stamen has two.
"Now the more dificult process is to separate the 3 annual ssp. of Castilleja listed above. First the most robust is C. rubicundula, also it is most often associated with damp grassland on serpentine .This rules out its occurrence on Pt. Reyes. The species found there is the somewhat-similar Castilleja ambigua ssp. ambigua, plants so appropriately-named, flowers all yellow with white-tipped bracts. It also grows in moist grassland. The one pictured above, which has reddish-purple leaves, is from Lake Lagunitas Meadows and is our only known remaining non-Pt. Reyes population. Saltmarsh versions, e.g. near Bolinas Limantour Estero and Inverness have some pink on the corolla and may be ssp. humboldtiensis.
"Surprisingly some of the yellowish-pink, white-bracted populations of Castilleja exserta ssp. latifolia (this forma not present in Marin, plants on the Manchester Dunes, Mendocino County for example) have been identified as Castilleja ambigua (see Calphotos.org) but the upper part of the corolla in each sp. is quite different. C. exserta has a large purple, fuzzy galea, C. ambigua has a slender greenish galea."
April 2010 Plant of the month by Doreen Smith
Marin's blue Larkspurs aka Delphiniums
Marin has five species of blue to purple-flowered Larkspurs, in Latin the Delphiniums. As they are very alike in the shape of flowers, to tell them apart needs a little work. The leaves are more distinctive but it is hard to keep the images of their respective shapes in one's memory.
The first to flower is Delphinium decorum, a coastal species. The ones about Pt. Reyes Lighthouse are short, few-flowered and very hairy. Other populations , e.g on the Marin headlands or other parts of Pt. Reyes are less hairy and taller. The ovaries are glabrous.
The second earliest to bloom is Delphinium patens, it grows in inland Marin, usually about the mixed evergreen/oak woodland margins. It is about 1 foot tall, deep blue or occasionally deep purple. It is glabrous in all parts, including the ovaries.
The next to flower is our rarest plant, Delphinium bakeri. Only two seem to be flowering (just started) this year along the Marshall-Petaluma road. The population was devasted a few years ago by over-enthusiastic road-bank and culvert maintenance. The U.C. Berkeley project to restore this species has it's first test out near Soulejule reservoir, where greenhouse-grown plants from salvaged seed have been recently planted.
Also at this same time of year Delphinium variegatum may be seen flowering on the lower slopes of Mt. Burdell. It has large, deep-colored flowers and hairy ovaries. Other populations, such as those about Turtleback Hill at China Camp include almost white-flowered individuals.
The last species to bloom, in May or even later is Delphinium hesperium, usually there are many flowers per stem. The Ring Mountain population is the best known. The flower's sepals (the brightly-colored perianth) do not spread open so obviously as in all the preceding species."
March 2010 Plant of the month by Doreen Smith - Fairy slipper orchid
Calypso bulbosa var. occidentalis
It may surprise many to know that this delicate orchid is common in March on the upper parts of Mt. Tamalpais, growing under Douglas'-fir trees and is probably mycorrhizally connected to them. There is only one leaf, often with several flowers, produced from a shallowly rooted corm-like structure. It is very vulnerable to trampling, so please take care if you want to photograph these little beauties. Examples are easily seen near the paved path to the Mountain Theatre from the small parking area just west of that site."
February 2010 Plant of the month by Doreen Smith
Zigadenes of Marin County
The Zigadenes in this area begin to flower this month. The earliest species are of the Zigadenus fremontii group, now likely to be put in a new Family, Melanthiaceae, and called Toxicoscordion fremontii! The following forms are all lumped into the same species.
On the S-facing slopes of Mt. Burdell there is a fine population of large-flowered plants with yellow anthers. This same form is present in the Marin Headlands along the Bobcat trail and on Ring Mountain .
On the immediate coast is a dwarf strain that can be seen on the headlands above Drakes Estero, east of the visitor center, near Marconi and at Oceana Marin, near Dillon Beach. This is the one pictured above.
The most common form in Marin is a tall variety with branching inflorescences and white anthers that's most usual in chaparral openings and especially after fires.
Also in serpentine chaparral, such as on the Carson Ridge, there is a small-flowered, unbranched form.
Occasionally a form can be seen in the upper edge of the Pickleweed zone of salt marshes.
Zigadenus micranthus var. fontanus = Toxicoscordion fontanum, is much later to flower (May) and usually is associated with seasonally-wet serpentine habitats, for example the seeps below Old St. Hilary's chapel, Tiburon and about Rock Spring, Mt. Tamalpais.
January 2010 Plant of the month by Doreen Smith
Chaparral currant - Ribes malvaceum var. malvaceum
This early-flowering shrub is apparently rare in Marin County. I have discovered only one specimen in my many years of botanizing here. That was recently, in 2008, after the new Marin Flora had gone to print but identification of a specimen was confirmed by staff at California Academy of Sciences in San Francisco. The plant was growing in the coastal scrub of the Marin Headlands along the Bobcat Trail, near the top of the hills, just west of the only willow tree on the south side of the upper parts of that trail.
The most common Ribes species that can be seen along the Bobcat Trail is Ribes divaricatum, straggly gooseberry, which is later-blooming, thorny, brown and white-flowered, so it is very different in appearance from either of the local pink-flowering currants.
Ribes malvaceum is very similar to Ribes sanguineum, the easiest-seen difference is that the leaves are smaller in R. malvaceum and the veins more incised into the upper surface of each leaf. Usually it is found in drier habitats than the more common pink-flowering currant in Marin. For comparison there are several shrubs of Ribes sanguineum var. glutinosum in the Marin Headlands by the lagoon just below the visitor center.
An account of this taxon is on P. 220 in the new edition of "Marin Flora".
December 2009 Plant of the month by Doreen Smith
Arctostaphylos nummularia var. sensitiva
Click on image for full photo
Marin plants of the shatterberry manzanita, Arctostaphylos nummularia var. sensitiva differ from A. nummularia var. nummularia of the North Coast of Ca. in several respects and will be separated in the soon to be published new treatment of the genus in the Jepson Manual #2.
The most obvious difference from the nominate variety is the presence of hairy stems and larger leaves in the more southerly populations of shatterberry, i.e. those of Marin and points south as far as Santa Cruz county. This dainty manzanita is easily recognized from all others in this area in having 4-merous flowers and lozenge-shaped fruits that shatter to release the seeds.
Plants can be discovered flowering all year (but most luxuriantly in late winter) in moist sites within the summer coastal fog-belt. Places to see the shrubs include the Bolinas Ridge, White Hill Open Space Preserve near the Camp Tamarancho property line, and the west side of Mt. Tamalpais starting at the altitude of the Throckmorton area of Mill Valley. There they can be viewed by the Mountain Home parking lot and along the roadside."
November 2009 Plant of the month by Doreen Smith - Carlotta Hall's lace fern, Aspidotis carlotta-halliae
This fern should by now have unfurled its summer-dried fronds on rocky serpentine areas of Mt. Tamalpais and at the tip of the Tiburon peninsula. It is a fertile hybrid of the two other lace-ferns known to grow in Marin, Aspidotis densa and A. californica. It is more like the latter in appearance but A. californica does not grow on serpentine areas.The type locality is near the Bootjack parking lot on Mt. Tamalpais.
October 2009 Plant of the month by Doreen Smith - Petunia parviflora
Last year, while on a field trip to Stafford Lake Park, Novato we found a new native plant species for Marin, a very small petunia, Petunia parviflora, a.k.a. Calibrachoa parviflora. This annual field trip was to look for late-blooming plants; the dried muddy reservoir shores are home to several species not otherwise seen in the County. This year, on a repeat visit, we found another new native species for Marin, alkali mallow, Malvella leprosa. The Petunia is very small, only about two inches tall, and the little purple flowers open only at mid-day so it is not easy to find them unless you know just where they are. In the same area are Persicaria amphibia, Heliotropium curassavicum and Epilobium pygmaeum.
September 2009 Plant of the month by Doreen Smith - Cuscuta spp., Dodders
Click on image for full photo
The dodders, Cuscuta species, are parasitic members of the Convolvulaceae. When mature the plants consist of orange-colored, non-photosynthetic strands draped over a host plant that completely supports their water and nourishment needs. The flowers are very small and white.
Of the Marin species, the most commonly seen species is Cuscuta salina, which is parasitic on pickleweed, i.e. Salicornia. Often it is very abundant out on the salt-marshes, for example those at China Camp State Historic Park, San Rafael. People have been upset by the vast masses of the parasite but it is a natural occurrence and the population of pickleweed always survives.
On freshwater-marsh plants, such as around Marin's reservoirs, Cuscuta pentagona is often seen parasitic on the weedy cocklebur, Xanthium stramonium. It can be seen at Stafford Lake, Novato.
In the chaparral of Mt. Tamalpais two species can be discovered. One, California dodder, Cuscuta californica, has very narrow, bright- orange strands forming a tangled mass on such hosts as Eryodictyon. The other is chaparral dodder, Cuscuta subinclusa. It has pale orange strands with clustered groups of flowers with longer corollas than the preceding species. In this case it's festooning Thermopsis californica near Rifle Camp, Mt. Tamalpais.
August 2009 Plant of the month by Doreen Smith "The two plants picked for this month's feature have not been seen in Marin recently.
If you find either of them you'll be (somewhat) famous!"
Cordylanthus mollis, soft bird's-beak, "was last seen in the salt-marshes along the Petaluma River north of Novato and near the Sonoma County line. It can be confused with the more common rare species Cordylanthus maritimus var. palustris, Pt. Reyes Bird's-beak, which is found occasionally in more southerly San Pablo Bayside salt- marshes. One such site is at the S. E. side of the Buck's Landing boat-launch area, Santa Venetia."
Lathyrus jepsonii ssp. jepsonii, Delta tule pea, "is a native sweet-pea of river margins that looks somewhat like the common weedy Lathyrus latifolius and has often been mistaken for it. For a correct identification look at the number of leaflets per compound- pinnate leaf. If there are only two then perhaps some tendrils you have an alien species of Lathyrus. The natives have 3 or more leaflets each side of the rachis."
July 2009 Plant of the month by Doreen Smith - Lilium pardalinum, leopard lily
This attractive and large lily is not uncommon in Marin and can be seen at Old St. Hilary's preserve, on Pt. Reyes in marshes and about Mt. Tamalpais in wet serpentinite areas. These images were taken along the Old Stage Road above and east of Bootjack Camp. They were growing with a huge Angelica tomentosa, Rhododendron occidentale and Toxicoscordion fontanum. Nearby there are some other rare plants; Cirsium hydrophilum var. vaseyi, Eriogonum luteolum var. caninum and Streptanthus glandulosus ssp. pulchellus.
June 2009 Plant of the month by Doreen Smith - Navarretia viscidula sticky navarretia
I'm pleased to report that on Sky Oaks MMWD the sticky navarretia, Navarretia viscidula, is in peak condition and coloring violet once-bare patches of the flatlands called Lagunitas Meadows. There are masses of this small but beautiful wildflower interspersed with the brown dried annual grasses that cover the areas with somewhat deeper soils.
May 2009 Plant of the month by Doreen Smith - Cerastium viride (was C. arvense), large flowered meadow chickweed
It seems we have acquired, by way of a taxonomic split of Cerastium arvense into two separate entities, a new plant for Marin. It is called Cerastium viride. This is the large white-flowered field chickweed of coastal Marin from sites along the Walker Creek bluffs, on Tomales Point, Chimney Rock trail and the Pt. Reyes Lighthouse. Though a plant with delicate-appearing fragrant flowers, it is a hardy perennial, surving strong spring winds and summer drought.
April 2009 Plant of the month by Doreen Smith - Indian paintbrush, now put into Orobanchaceae
Castilleja subinclusa ssp. franciscana Franciscan paintbrush
The bright red-orange spikes of this paintbrush are conspicuous in the coastal brush. Along Shoreline Highway 1 north of Stinson Beach they are often flowering as early as mid-February. Later fine examples can be seen about Nicasio reservoir. On the outer bluffs of Pt. Reyes the inflorescences can be more compact and the bracts a deeper red than further east in the County."
Castilleja affinis, common paintbrush
Marin has other species of red paintbrush, also all hemi-parasitic, they look very similar to the above. The most obvious difference being the flowers do not bend at right-angles to the stem axis like the Franciscan paintbrush because in common paintbrush the red calyx is slit equally on both sides and the flowers are upright against the stem.The common paintbrush is very variable in appearance and perhaps several entities are lumped into this taxon. They can be seen growing in open grassland or on well-drained roadside banks near mixed evergreen woodland. The plant pictured was growing near Pt. Reyes Lighthouse visitor center with the large native bunch-grass, Calamagrostis nutkaensis.
"Our other two red paintbrushes are C. foliolosa, the wooly-leaved chaparral paintbrush and C. wightii, coastal paintbrush - which latter can have red flowering spikes as well as the more usual pale yellow. Also the various coastal species have the reputation of hybridizing just to make things more difficult for us to identify them.
March 2009 Plant of the month by Doreen Smith - Claytonia exigua ssp. exigua, C. gypsophiloides - and similar Claytonia spp.
A tiny plant, Claytonia exigua ssp. exigua, is common in Marin, mainly on serpentine but occasionally on other soils . The flowers are white, the usually grey-green leaves are linear or needle-like and in a rosette . It is a relative of the much large plant, miner's-lettuce, Claytonia perfoliata, this latter is very variable in leaf characteristics.
A similar white-flowered species to C. exigua is Claytonia parviflora ssp. parviflora which is usually in shaded places on sandstone-derived soils. Some can be found along the N.-facing part of the Verna Dunshee trail, Mt. Tamalpais.
Also there is C. gypsophiloides, which has large, pink flowers. Compact, fleshy plants of this occur on the Carson Ridge, more wispy, delicate plants grow on serpentine elsewhere - sometimes they are numerous enough to give a bare, rocky area a pink haze of blossoms.
It may be difficult to decide which small Claytonias you have found, even if you try to key them out very carefully. The Calphotos.org pictures don't help much as the images there are not yet verified by an expert!"
February 2009 Plant of the month by Doreen Smith
Garrya, (Silk Tassel)
Garrya elliptica, coast silk tassel, is a very early flowering shrub that's quite common in Marin County from Pt. Reyes to Mt. Tamalpais. Leaves are very hairy beneath and grey-green in color. Each shrub is either male, with long, staminate catkins, or female with short, stubby, pistillate catkins. Examples can be seen in Tomales Bay State Park, near Heart's Desire Beach and around the Verna Dunshee east- summit trail on Mt. Tamalpais . Also other places by roadsides, such as just west of the Big Rock redwood grove where they can be noticed just this month.
"Garrya fremontii is rare in Marin, being seen only above 2000 feet on Mt. Tamalpais such as at the roadside - beginning of the International Trail . Again each shrub is either male or female (dieocious) but the leaves are yellow-green and hairless. It flowers a little bit later than the previous species but still in January. There are records in the UC/Jepson herbarium that suggest two other Garrya species occur on Mt. Tamalpais but no-one in Marin CNPS has reported seeing them recently.
January 2009 Plant of the month by Doreen Smith - Madrone, Arbutus menziesii
Madrone, Arbutus menziesii, produces strands of colorful berries at this time of year. They are edible but better left to the birds as the taste is uninspiring. Good examples of these trees can be seen in many places in Marin, such as on the northern slopes of Mt. Tamalpais. The MMWD Sky Oaks property has some near the Lake Lagunitas parking area. The trees, if free of disease, are handsome in all seasons with large glossy evergreen leaves, colorful bark and, in spring, snowy bell-shaped flowers. Unfortunately this species is difficult to establish in a garden unless it is part of the remaining natural vegetation of the site.