Wednesday, April 22, 2009

Farewell to spring?

While I do mark my seasonal progress by the plants in flower, the actual progress of the season is well beyond my control. A four day heat wave during the third week of April is enough to tip the balance for many plants. During this short span, lush green hillsides turned tan on their southern and western flanks as annual plants dehydrated by the millions.
To mark this turn toward our dry season, two plants on our property along Garnett Creek here in Calistoga at the N end of the Napa Valley, have made their debut.
Perhaps the more impressive in terms of sudden appearance is the native bulb (corm) called ookow or wild hyacinth, Dichelostemma congestum. Just last week while walking our trails with a friend, I was looking out at the hundreds of blue dicks, Dichelostemma capitatum, and commented, "I wonder when the ookow will appear?" It has been a tremendously successful year for blue dicks, some landscapes tinted a lilac-blue haze with their hundreds if not thousands of flowering heads. But last week, while there were still dozens and dozens of blue dicks in flower to be seen, I could not find a single ookow, which I knew should follow in floral sequence.
New on the scene, ookow, Dichelostemma congestum.
Today, in the same spot there was not a single fresh blue dick to be seen, but hundreds of ookow - a complete reversal. Given their similar appearance, often identical sites and this "presto-chango" sucession, it is no wonder people assume they are the same plant - a cluster of blue-lilac flaring tubular flowers clustered in a head waving on a tall stem above the grasses.
Closeup of ookow. Each flower has three fertile stamens, the other three modified into staminodea, here as three projecting pieces of petal-like tissue colored identical to the petals, each have a forked (split into two) tip.

Forked (or bifid) staminodes flank anthers in center of flower. Pink chalices replace dried up larkspur (subject of Two Blues blog) on sunny hillside.

The second plant to put in an appearance is appropriately commonly named, Farewell-to-Spring, the species I have is graceful farewell-to-spring, or Clarkia gracilis. Last week I noticed the first few, but by today there are sweeps of pink. It is similar to many other Clarkias in being a relatively large, cup-like flower, much like a small tulip. Named for William Clarke of the famous Lewis and Clark expedition of 1804-1806, these large cup type is sometimes called Godetias - and often the horticultural hybrids still are sold as such.
Satiny petals of Clarkia gracilis, this plant with unspotted petals.
The Clarkia gracilis on my hillside hasboth spotted and unspotted forms, some undecided. The species is fairly widespread, but has a number of named races (subspecies). All are exquisite, but the subspecies albicaulis, is unquestionably the showiest with huge tri-colored flowers - a must-try if you see it in a nursery or catalogue (not shown here).
Spot the difference?

The cross-shaped (cruciform) stigma (female receptive organ) can be found in many genera of plants in the Evening Primrose Family (Onagraceae), though not all.

Undecided about spots. Ambivalence is not just a human trait.

The race here qualifies as the subspecies sonomensis, the Sonoma graceful farewell-to-spring, though here we're in Napa Co. However having a spot is part of the defining character of this subspecies, so where does that leave the unspotted ones?

Clarkias are one of those annuals that can be very plastic with their form depending on resources; sometimes very tall (2'+) and branched with large (2") petals, other times shrunken into miniature single flowering plants only 2" tall with half inch petals.

Close up of Diogene's lantern, Calochortus amabilis.
Another plant to mark the season is the native bulb called Diogene's lantern or yellow fairy lantern, Calochortus amabilis. The botanical name, Calochortus means beautiful grass, while, amabilis means beautiful, thus we have a beautiful, beautiful plant (with grass-like foliage). I saw my first in flower nearly a month ago, but now is when most are in mass flower. It is one of three species of nodding yellow-flowered calochortus, the smallest in most features, but also - and this is important to plants - by far the most widespread.

Although we don't generally go around carrying lanterns anymore, it would make a lovely design for one. Reminds me of those ceiling fan/light globe combos so popular today.

Diogenes was the third century BC Greek philosopher and all around curmudgeon who walked the streets of Athens carrying a lantern during the day, "looking for an honest man", which cynically implied a fruitless search. Heavy stuff to put on a wildlfower. Searching around the North Bay looking for an honest wildflower display, would not be fruitless, as this lovely lily family member is common on slopes and canyons in many spots in the North Coast Ranges, though it is not everywhere.

Monday, April 20, 2009

Azalea time

Plant people tend to mark their seasons not so much by the calendar date as what is flowering now, or just about to flower, especially with plants for which we feel special affection.
A plant that really marks the middle of springtime for me is the flowering of Western azalea, Rhododendron occidentale, a deciduous shrub that is frustrating to grow well in gardens, but which performs magnificently in the wild.
This shrub, generally about head height, dominates the margins of the all the lower creeks and seepages in The Cedars, in Sonoma County, California. For anyone new to this blog, a few words about The Cedars. It is a large area in NW Sonoma Co. composed entirely of serpentine rock called peridotite, most being a particular form called Harzburgite. Serpentine rock, and its derived soils, are hostile to most plant life, thus the plants that grow on serpentine areas tend to be unique or unusual. The Cedars is roughly about 7,000 acres of this rock, and is eroded into deep canyons with perennial water in the lower reaches. To view The Cedars on Google Earth, the approximate center is; 38(degrees)37'25.99"N and 123(degrees)07'02.86"W (sorry, I can't figure out how to insert a degree symbol in this program). Western azalea, while tolerant of serpentine soil with permanent water, is not restricted to this rock type. It can also be found along creeks and rivers in the Coast Ranges and Sierra Nevada, as well as coastal meadow/prairie. It is especially common in the mountains along creeks and in wet meadows. While the plant is surprisingly shade tolerant, it flowers most heavily when exposed to lots of sunlight - thus those at The Cedars, which often are out in full sun, can produce masses of flowers.
Western azalea in full sun on bank above creek.
At The Cedars the flower color is similar to that found in much of North Coastal California, that is, it varies from a relatively rich rose pink on some shrubs, to almost pure white on others, and most inbetween. All have a large golden or orange spot on the enlarged upper petal.
White flowered Western azalea.

Deep rose pink flowered; in all, the deepest color is on the reverse side.

The flowers produce a strong fragrance that most people find intoxicating, and inevitably the urge to bury your face in the glowing floral mass is impossible to resist. The fragrance is a rather heavy floral sweetness with hints of spice, and just a touch of skunkiness. The mefitic (skunky) component is due to the oily gland-tipped hairs that cover the outside of the flowers and young foliage. This gives Western azaleas a fragrance that is quite unique and memorable, while being highly enjoyable.

Although considered a gorgeous shrub, it has proven very difficult in cultivation; very slow growth, devastating powdery mildew in summer, and reluctance to flower being some of the common problems. In general, almost any plant seen in the wild looks better than the best-grown plant in cultivation, though of course, there are exceptions. The irony is that, especially in sites like The Cedars, the plants are growing exceptionally well, yet are growing in conditions that should be anathema for any self-respecting rhododendron. Here they grow in full all day sun with harsh reflected light and high heat, often in rock crevices devoid of any humus, no nutrients, and often with highly alkaline water - any one of these conditions enough to kill most azaleas or rhododendrons. Go figure!

Thursday, April 16, 2009

Powerful fragrance, dreadful reputation

Of all the California native plants, poison oak, Toxicodendron diversilobum, is easily the most dreaded and feared. In fact the standard reference for California plants, The Jepson Manual (Hickman 93) states "one of the most hazardous plants in California".
Indeed, for those allergic to its oils - which is probably most people - it is a major deterent to enjoying natural areas throughout most of the state. And there is no issue here with denying its often extreme effects - agonizing rashes and ceaseless itching which can incapacitate a person and even lead to serious medical complications.
Few people have much positve to say about this plant which can be nearly omnipresent in some areas. But not everyone is allerigic to it, or only minimally so, and so it is easier for us to look at the plant perhaps more objectively.
It is an impressive plant in many regards, able to thrive in an enormous range of habitats and situations. It has many forms; groundcover, clinging vine, massive sprawling shrub colonies, or isolated free-standing shrub. It grows from sealevel into the lower mountains and from the coast to the edge of the deserts. It is tough, repsrouting quickly from damaged stems and root fragments, and is hard to eradicate completely without repeated efforts.
It is well-known for its early "fall color", as it goes dormant as early as late June in some sites, to late fall in more favored habitats. It produces gorgeous coloration as it goes dormant, and this process can linger for months, creating a tapestry of yellow, peach, salmon, raspberry to rich glowing scarlet and red. Folks who detest the plant will see these colors and say to themselves, "Yikes look at all that horrid poison oak, it's everywhere!" Other, like myself, will say, "What a treat to have so much color so long in the summer landscape."
But a feature surprisingly few people associate with this plant is its intense sweet and spicy fragrance when in flower in the spring. It is perhaps, after Ceanothus (California "lilacs"), second to none in its fragrance, and a very lovely fragrance at that.

poison oak with small flowers
Why so few people know it as a fragrant plant is perhaps understandable, given most folks reluctance to be anywhere near it. Also, the flowers are quite small, though often produced in strings or branched clusters in great numbers. But one doesn't have to stick your nose into the plant to enjoy its scent, the scent carries freely on the air, often forming large plumes of spicy sweet scent that drifts throughout the landscape. Often while driving with the windows open, I will smell it first and then look around and notice a large mass of it dozens of yards away on a bank. Or while walking in the woods you may pass in and out of the fragrance repeatedly, each time thinking, "What a wonderful fragrance!" Most will glance around trying to figure out what is causing the fragrance, and will either be perplexed or attribute it to some showier plant in flower nearby.

tiny 5 petalled flowers don't look like much but pump out the fragrance
The fragrance is closest - to my sense of smell - to carnations or dianthus (pinks), that wonderful combination of spice and sweet that most want to inhale deeply again and again. Trying to emphasize the postitive, what a treat to have so much delightful fragrance given so freely by a plant that is so common and widespread. No need to toil over beds of carnation or cottage pinks with their short season, need for rich prepared soil, water and fertilizer, and weeding and dead-heading. Here we get all the fragrance and none of the work!!!
Another plus is the fragrant season is quite prolonged, especially in the canyons, where the sunny plants will flower weeks before those on shades slopes. And even when they are finished in your area, one only has to drive up to a higher elevation to enjoy the flowering season again, and again. Follow up note: after posting this, a few folks have told me that they can absolutely not detect a fragrance from this plant. While I find it hard to believe, given the intense fragrance I get from this plant, it is the nature of fragrances to be of variable perception among various people.

Monday, April 6, 2009

Two blues

Rich saturated glowing blue color in flowers is rare.
On our property here in Calistoga, CA, we are fortunate in having three native larkspur, genus Delphinium, the scarlet Delphinium nudicaule, the dark purple-blue D. decorum, and the cobalt blue to purple-blue D. variegatum. I do not want in any way to disparage the other two for they are exceptional species, but the glistening cobalt blue D. variegatum is hard to get enough of.
It is hard in these smaller photos to capture the glistening quality of the petal surface which have both the "diamond-dusted" and "crepe-like" characters seen in plants such as bearded iris or some poppies.
This species seems to have more color variation than either of the two other mentioned which are fairly constant. One extreme here is the darker purple type.
This species grows in clay soils that are wet during the winter months, often with water oozing from the bank edge where these grow here. The other two have their distinct habitats; the scarlet larkspur grows in fractured rock and rubble, while the D. decorum grows on steep slopes in a clay/gravel mix typically at the edge of woodland or under deciduous oaks. This is a drift of the larkspur on the edge of a precipice in Calistoga. Over the years I've seen many fabulous displays of this native plant. Perhaps the most memorable was several acres of vernally wet clay meadow called Morgan Valley near the Reif-Rayhouse Rd. in southern Lake Co.
As glorious as this larkspur is to enjoy in the wild, it is not considered transferable to a garden setting, though folks will keep trying. The larkspurs in horticulture are generally preferable in this regard, though even those can be a challenge -but one with great reward.
A plant that I grow in my garden here in Calistoga that shows great promise for a stunning blue flowered panicle several feet tall is the rare Echium gentianoides, or tajinaste azul. It is restricted in the wild to the mountains on the island of La Palma in the Canary Island group. Annie Hays of Annie's Annuals has propagated this beauty. I was initially cautious, as other Echium species have become noxious weeds in the coastal regions of California. But I cut up the seed stalks of E. gentianoides last year and have not seen a single seedling yet in my garden, though I'll continue to monitor the situation.
Two views of the Echium in front of a large Spanish olive oil urn, pictures taken yesterday. It is an unusual Echium as the leaves are not bristly hairy but smooth with a lovely silver-blue color and pinkish petioles and stems. It is very heat and drought tolerant here, though the plants go into a semi-dormant late summer phase, but come back quickly during the winter. According to Warren Roberts, superintendent of the UC Davis Arboretum, it comes from areas that receive snow, thus is hardier than many of the other echium. I do not know, however, what the bottom line is for temperatures, as our Calistoga garden is amazingly mild with no freezes in 3 years.

I originally bought 3 plants, two are this rich deep blue while one is paler, but still an excellent color. I believe they are currently all seed grown, so some variability is to be expected - so if you come across it, buy several. Also can be ordered from Annie's website, http://www.anniesannuals.com/.
The botanical species name, gentianoides, refers to the rich blue flower color that is simiar to that commonly found in the genus, Gentiana, or gentian. Gentians are often plants of mountain meadows and are noted for their deep blue flower color, gentian-blue often being used as a color name.

Saturday, April 4, 2009

Strep Trekking 1, some observations on the genus Streptanthus, the jewelflowers

Plant obsessions are odd enought to start off, but to be fascinated with a small-flowered mustard relative that few people will ever notice is probably weirder. Streptanthus, is Greek for twisted flower, but it is actually the wavy-margined petals that give this impression. The common name of jewelflower, is quite appropriate for many species given the intricate detail of the flowers and their often glistening colors.

Bristly jewelflower, Streptanthus glandulosus, Calistoga CA

I have the great fortune, and indeed it is a sort of personal wealth, to have populations of Streptanthus on two different properties we own, one species here in Calistoga CA and three full species (with many variant races) at The Cedars, in Sonoma Co.,CA.

Jewelflowers occur in much of California, though they are seldom common, and typically are restricted to rocky sites and odd soil or rock types. Many are restricted to serpentine rock and soil. Having spent 30 years exploring serpentine sites throughout California, I got to meet a lot of Streptanthus - some extremely rare. Indeed it would be hard to "know" CA serpentine plants without getting to know Streptanthus. As with other complex species groups, it has been hard for botanists to concur on what name goes on what plants. Some variation is profound with strange characters appearing almost as if Dr. Seuss was directing evolution. Other variation is extremely subtle, slight changes in size, flower color, leaf shape, etc. Genetically it seems like the plants are not quite ready to "settle down" to a consistent form; there are still too many options to explore. One feature shared in many jewelflower species is a dramatic change in foliage from the seedling rosette as it matures into the flowering plant. Some species drop their lower leaves by flowering which makes identification more difficult, since only the atypical upper leaves may remain. Bearded jewelflower, Streptanthus barbiger, juvenile foliage rosette left, in flower right. Note the strange brownish-pink-amethyst color of the juvenile leaves, they almost mimic the gravel color of the serpentine rock. The botanical name means bearded jewelflower (barbed, barber, beard, etc. all come from that latin root), but ironically most populations and races do not have hairs (beards) on the flowers. This shows that botanical latin, while having to meet certain rules, does not have to correctly describe the plant; although for fairness sake, some plant probably did have hairs. This species is restricted to the North Coast Ranges of California and always is found on serpentine soils or rock, often at great distance from its nearest neighboring population. The plants above are from The Cedars in Sonoma Co. The juvenile was photographed April 3rd, the flowering plant last year in May.
A jewelflower that occurs both here in Calistoga (Napa Co.) and in two forms at The Cedars (Sonoma Co.) is the bristly jewelflower, Streptanthus glandulosus, a widespread though infrequent species of both the Central Coast Ranges and the North Coast Ranges in California. It is frequently found on serpentine rock/soil, but is also on other rock types such as volcanic, sandstone, cherts, etc.
This seedling of bristly jewelflower illustrates where its common name comes from; most foliage and even lower stems are densely covered with bristly hairs. As the plant grows, most will also produce glandular hairs, i.e. hairs tipped with a sticky exudate, thus the botanical species name, glandulosus. Both the bristles and the glandular secretions are intended to deter predation by animals and insects. As will be mentioned below, there are a number of races of this species, but nearly all look identical at this juvenile phase. This species is also an exception to the generalization mentioned previously about the upper foliage changing dramatically; in bristly jewelflower it changes slightly, usually becoming gradually smaller and less toothed as the plant elongates.
The race of bristly jewelflower that is found extensively within the canyons of The Cedars (Sonoma Co.) has rose-pink calyxes (the cup-like bowl from which the petals emerge). In the past this was given the botanical name of Streptanthus glandulosus ssp. secundus var. hoffmanii, or Hoffman's jewelflower. Hoffman was an amateur botanist who extensively explored serpentine sites in Northern California, particularly The Cedars area in Sonoma Co. which forms the headwaters of the two branches of Austin Creek. He was also fascinated with the genus Streptanthus. It was Freed Hoffman who coined the term, strep trekking, my title of this series.
Here's another race of bristly jewelflower which is found outside of the canyons of The Cedars (Sonoma Co.). In the past, this race was called var. sonomensis, or Sonoma jewelflower. It is similar to several races of jewelflower found in Marin Co. to the south, but is restricted to Sonoma Co. Even within the county, there are several color forms; white with pink, white, white with yellow or yellow. This is the typical color form of bristly jewelflower, a very dark, almost black-red-purple calyx. These are plants found near my home in Calistoga (Napa Co.), but this color race occurs predominantly throughout its extensive range. A very similar color, though even darker and with smaller flowers is the rare Tiburon jewelflower, Streptanthus niger, found in only a few sites in Tiburon, CA (Marin Co.), the best known site is adjacent to the historic St. Hilary church.
This topic to be continued periodically.

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