2019 - Robert's botanical adventures in Northern California

[Robert]

ELDORADO NATIONAL FOREST
El Dorado County, California

Thursday, 23 May 2019

Part I

Weather for selected location

Eldorado National Forest, 5,450 feet, 1,661 meters
Weather: Rain Showers
Temperature, High: 54 F, 12.2 C
                       Low: 36 F, 2.2 C
Relative Humidity: 63%
Dew Point: 36 F, 2.2 C
Wind: E 3G5
Precipitation: 0.18 inches (4.57 mm)




Last week’s outing was very interesting and productive. Weather/Climate has a major impact on plants both in our gardens and well as in the wild. To help put this outing in perspective, a summary of our weather conditions over the past 45 days might help provide clarity to my observations and the topics discussed.

Late April and early May were dry with periods of above average temperatures. A few daily high temperature records were broken in late April. In mid May a strong East Asian Jet propagated eastward over the Pacific Ocean (indicative of El Niño conditions and/or a positive Pacific / North American Pattern). This brought a series of late season storms to our region with low snow levels for May – 5,000 feet (1,524 meters). This was followed by series of short wave weather systems rotating around cut off lows pressure systems caught in the northwesterly flow over our state. This brought a continuation of the cool unsettled weather and thunderstorm activity. Precipitation amounts for May hit record, to near record levels. A new precipitation record was set for Sacramento and at the Placerville farm precipitation amounts reached near record levels. The May precipitation event was indicative of El Niño conditions in the equatorial Pacific Ocean.

For much of May, warmer-than-average SST (surface sea temperatures) persisted over the central tropical Pacific Ocean, with weak trade winds in the western Pacific. This is a typical and familiar El Niño type pattern. In mid-May an active MJO (Madden Julian Oscillation) moved from the Western Pacific Ocean to the Western Hemisphere then stalled out. This event coincided with our May precipitation event.

Currently, SST are continuing to build in the central Pacific, with a continuation of the weak trade wind pattern in the western Pacific. I will be watching conditions closely to see what develops. Generally in June, during the beginning of the East Asian monsoon season a warm, moist, low-level southwesterly flow develops over the Indian Ocean pushing northeastward toward India and southeastern Asia. This flow can often “nudge” the warm waters in the western equatorial Pacific Ocean and initiate a down welling oceanic Kelvin Wave to propagate eastward across the Pacific Ocean. Such an event will help prolong the current El Niño and impact our weather here in California.



I spent the early part of the morning at a low elevation site (3,600 feet, 1,097 meters) in the canyon of the South Fork of the American River before moving on to the Montane Basin at 5,450 feet (1,661 meters).

On my last visit to this site on 1 May, despite 2 weeks of unseasonably warm temperatures, many plants were still dormant. On this outing many species had broken dormancy and were in active growth. Many plant species are vulnerable to extreme cold temperatures and/or ultraviolet radiation during this transition period. Plants have a number of methods to deal with these conditions. Understanding these coping mechanisms can often be essential to the successful cultivation of a species.

Pictured is a nice specimen of Cymopterus terebinthinus var. californica in active growth. I have a number of site-specific temperature data recorders in this area. Despite 7 to 10 cm of snow cover during the previous 5 to 7 day period, there were no temperature extremes during this time period. Despite some below freezing temperatures, I did not observe any frost damage on any plants in the area.

UV-B radiation is a bit more complex. The high albido of snow cover can concentrate UV-B radiation on specific sites. In addition, under certain meteorological conditions UV-B can also be concentrated, sometimes as much as 50% greater than the solar constant. Alpine and montane plant species have excellent methods to protect sensitive tissues from this radiation. Unfortunately, attempting to cultivate plants at lower elevations can sometimes interfere with these processes leading to the death of the plant.



Castilleja pruinosa is a beautiful species. This plant was well advanced in growth and will be blooming soon.



Some plants were slow to activate after their winter dormancy. Here Eriogonum wrightii var. subscaposum is no longer matted from heavy snow cover and is starting into active growth. Other plants of this species were much more advanced in their growth. Snow cover days and exposure are two important variables in this regard.



This specimen of Pellaea bridgesii is another example of a plant slow to recover from winter dormancy. Once again other specimens were well advanced with new growth. Avoidance of extreme cold temperatures is a common survival approach for many alpine and montane species. Plants growing from crevices and protected by rocks, in general, were responding much better than this specimen pictured growing exposed and out in the open.

[Robert]

ELDORADO NATIONAL FOREST
El Dorado County, California

Part II

Occasionally I see die-out or partial die-out on plants after the spring snowmelt. Most often this is observed on Penstemon newberryi var. newberryi. With Penstemon newberryi, die-out and partial die-out is most often seen on plants that have become partially shaded by other plants or are covered by snow very late into the spring season. At this time temperatures have warmed a great deal yet the snow is still lingering at specific sites. Plants can be susceptible to snow molds under these conditions.



After snowmelt, excessive leaf-drop on Huckleberry Oak, Quercus vacciniifolia, is observed much less frequently. The specimen retained very few leaves this past winter.

Understand why plants become distressed and preform poorly in the wild can be just as revealing to their domestic cultivation as can the understanding of wild plants when they are thriving in the wild.



Senecio integrerrimus var. major emerges quickly after snowmelt. Once active growth begins, this species quickly develops flowers and seed before the onset of summertime high temperatures and extreme dry soil conditions.



Montane and alpine plant species that emerge quickly after snowmelt also need to contend with late season snowfall (and early autumn snowfall). This specimen of Senecio integerrimus var. major was buried by 10 to 15 cm of snow about 5 days prior to when this photograph was taken. It might have been slightly pressed down by the snow, however now that the snow has melted away this plant it is ready to grow again.

This scenario does not always play out in this manner. I have site-specific temperature data recorders at this site and noticed that there were no sub-freezing temperature extremes before or after the late season snow event. Many species are extremely vulnerable to excessively cold, freezing temperatures after they begin active growth in the early spring. Exposed plant organs can be injured and burned back to the ground or the snow level during extreme cold weather events during this period of time.



Ribes roezlii var. roezlii blooms very early in the season in the Sierra Nevada Mountains and is resilient to freezing temperatures when in bloom.

[Robert]

After spending some time on the higher slopes above the basin, I moved down to the flats to check the conditions and plants in this area. Although much of the snow had melted, conditions were very wet and swampy.



Sceptridium multifidum was rebounding from its winter under the snow. This species requires about 10 to 14 days after snowmelt to perk up and resume active growth. This delayed metabolic activity is one of several strategies that plants use to protect vulnerable tissues from damage after snowmelt.



Veratrum californicum var. californicum is often the first species to emerge after snowmelt. Often a site will be bare of visible plant life immediately after snowmelt. Frequently I see Veratrum californicum emerging from the ground at such sites before other species emerge or other species begin germinating.



Viola adunca ssp. adunca is seen frequently in moist meadows in the higher elevations of the Sierra Nevada Mountains. This specimen was quick off the mark to start active growth and was already in bloom.



I always check conditions at the two ponds. On my last visit on 1 May there was a choirs of Pacific Treefrogs, Hyla regilla, calling when I visited. On this day it was completely quiet. I looked for tadpoles and egg clusters but did not find any. There was still a good flow of water into this pond. Later in the season it will be completely dry. The Pacific Treefrogs generally take advantage of any standing water to produce their next generation of frogs.

[Robert]

Near the lower pond there is a patch of higher ground that is interesting to explore. In scattered locations there were still stands of Greenleaf Manzanita, Arctostaphylos patula, in bloom. Manzanita flowers are an excellent early season food source for many wildlife species.



Allium obstum var. obtusum enjoys the rocky and drier terrain above the flats.



Someone had recently been digging the Allium bulbs.  There is at least one bear that lives at this site, however I am uncertain whom exactly was digging the bulbs. Before I arrived at this site some Common Ravens, Corvus corax, flew away from this area. I have never heard of Ravens eating Allium bulbs, but I learn new things all the time.



Viola tomentosa is another species that prefers the higher and drier terrain above the moist flats.



Sanicula tuberosa is also found on higher terrain, however this species is frequently seen where there is a great deal of residual moisture after snowmelt. The species is never found in the perennially mesic soils of the flats.

[Robert]

At sites that were well exposed to solar radiation, I found the first Phlox diffusa flowers opening.



The very early morning hours started out with mid-level strato-form overcast. The overcast skies gave way to generally clear skies about 2 hours after sunrise. The atmosphere was unstable with both low-level and mid-level lapse rates running high and plenty of moisture available for thunderstorm formation later in the day. I needed to keep an eye on the convective type cloudiness that was forming.



This site was logged of its oldest timber about 15 years ago (~ 2005). As a perspective, I counted 273 tree rings on this stump. The core of the tree had rotted-out, so there may have been as many as 50 more years of growth. Just using the rings I could count, this tree was a seedling in 1732, however it most likely germinated as a new seedling in the late 1600’s. The term “sustainable forestry” sounds good, but what does it really mean?



Many of the site’s annual species had germinated and were well into growth. Diplacus (Mimulus) torreyi can be found over a wide altitude range in this portion of the Sierra Nevada Mountains. This species adjusts uniquely to each of the various climatic/ecological zones within its range.



As with the seedlings of many species that grow in the montane and alpine life zones, the young seedlings of Diplacus (Mimulus) torreyi produce a great deal of anthocyanids to protect sensitive tissues from UV-B radiation when they are young.

[Robert]

ELDORADO NATIONAL FOREST
El Dorado County, California

Part III

Hemizonella minima is a common annual throughout the Sierra Nevada Mountains. The seeds germinate quickly after snowmelt and the seedling will quickly begin to flower. Mature flowering plants are frequently only a centimeter or two tall.



From the upland site, I moved to another portion of the basin. Here many seasonal creeks flow down the mountainside into the basin. By mid-summer the streams will be completely dry.



In this area there is a grand old Sugar Pine, Pinus lambertiana. Sugar Pines can grow very tall and become large in girth. This tree is 4.970 meters in circumference at 1 meter above the ground.



The snow lingers in this portion of the basin and many of the herbaceous perennial species were just emerging from the ground. Little Prince’s Pine, Chimaphila menziesii, is a small evergreen species that is a member of the Ericaceae Family. This species thrives in this shaded coniferous woodland plant community.



The coniferous woodland eventually gives way to a more open plant community with scattered conifers. There is one location where there is a colony of Lewisia nevadensis growing on a gravelly bar next to a seasonal creek. During the early growing season, conditions are very moist, however by mid-summer this site will be parched and extremely dry. I often find Lewisia nevadensis growing under such conditions. This Lewisia colony is located at an elevation of about 500 to 1,500 feet (152 to 457 meters) below their usual altitude range in this portion of the Sierra Nevada Mountains.

[Robert]

In more densely forested areas I found Viola sheltonii emerging from the ground.



The snow was still in the process of melting in the more sheltered sites. I did manage to find one specimen of Viola sheltonii with flower buds, however most of the plants had yet to progress to this point of development.



Viola purpurea ssp. integrifolia is found in much more sunny and open sites than Viola sheltonii.



The first flowers were open on many of the specimens of Viola purpurea ssp. integrifolia. The comparative blooming phenology of Viola sheltonii and Viola purpurea ssp. integrifolia is extremely interesting. On Peavine Ridge, within a thermal belt, Viola sheltonii consistently emerges and blooms before V. purpurea ssp. integrifolia. This is a consistent occurrence on Peavine Ridge regardless of the number of snow cover days. The opposite is true in the Montane Basin only 300 feet (91 meters) higher in elevation than the Peavine Ridge site. Consistently Viola purpurea spp. integrifolia is the first to emerge and bloom in the Montane Basin. Climatically the Montane Basin is a cold air basin, has differing wind circulation patterns, and has additional specific microclimatic idiosyncrasies.



At one specific site there is a very fascinating colony of Viola tomentosa hybrids. When I first discovered this colony last summer I was uncertain as to their true identity. They have a close affinity to Viola purpurea ssp. mesophyta, however they lack several important taxonomic features of this subspecies. The other possibility I considered at the time was that they could be hybrids, Viola tomentosa x V. purpurea ssp. integrifolia.  After a careful taxonomic study and review I am inclined to believe that they are, indeed, Viola tomentosa x V. purpurea ssp. integrifolia hybrids. This population of fertile hybrids shows very little sorting in the F2 generation, which leads to further questions. I will keep you posted to my findings as I continue to study this unique stand of Violas.

[Robert]

In another portion of the basin I found other Viola tomentosa x V.purpurea ssp. integrifolia hybrids. They share many of the same attributes from the former colony just discussed, however as one might expect, there are also clear differences.



At this site, one of the first species to emerge after snowmelt is Ranunculus occidentlais var. ultramontanus. As the snow is melting it is most often seen growing next to or in shallow running water. As the season progresses and conditions dry a bit, it will continue to grow and bloom as long as the soil stays moist. Once the ground begins to dry, like many other California native species, it will dry off and become dormant for the summer season. During this dry summer dormant period it requires completely dry conditions to remain viable.



Soon other shrubby species join Greenleaf Manzanita in the early season blooming progression. Here, in this photograph, Ceanothus arcuatus has commenced blooming with its white to pale blue flowers.



On higher and drier ground above the basin floor, I spent time looking for the native annual Phacelia stebbinsii. In places there was an incredible amount of water seeping around the large boulders. This was the perfect habitat for Micranthes aprica. This species, too, enjoys vernally moist sites that become dry during their summer dormant season.



I had a very good idea where to look and had no problems locating Phacelia stebbinsii. The seedlings were well advanced and will be blooming soon.

[Robert]

About 1:00 p.m. in the afternoon menacing convective cloudiness started to appear. I decided to leave the site via another route. In a sunny, dry, rocky environment, I found many specimens of Viola tomentosa in bloom.

Viola tomentosa has a preference for rockier and drier sites than Viola purpurea ssp. integrifolia. All things being equal, Viola tomentosa also tends to bloom a bit later. Despite these differences the two species can frequently be found growing and blooming at the same time in the same general vicinity. Hybrids between the two species do occur and the hybrids tend to be fertile. I have examined many specimens of each species where the two species over lap in their distribution. Despite their ability to produce viable hybrids, the two species appear to maintain populations that are reasonably “pure” and true to type where their populations overlap.

From this point, I hiked back to the Outback as a cold light rain began to fall. My timing was perfect. Shortly after starting my return trip heavy snow started to fall. In addition, there was no shortage of lightning. Everything worked out well!

Until the next time…

[hamparstum]

Robert, I'm fascinated about your Violas. They seem to span quite a wide range of ecological niches. I clearly understand their potential in gardening. A huge amount of experimenting will be required. However as us gardeners move away from uniformity in garden conditions ( which is one of the main obstacles a horticulturalist faces) then different cultivated forms can emerge that are adapted to different gardening conditions. In my place I'm blessed to have many varying ecological conditions from very dry and almost barren ground all the way to bog like spots, both sunny and shaded. In all I could garden if I were to identify the adequate combination of plants. I suspect that apart from Penstemon and Castilleja, Viola will also give these wide array of options. Mimulus is one other group to research this way.
Arturo

[Robert]

Arturo,

As things currently stand, many of our California native Viola species are not easily grown. It will take a considerable amount of work and detailed understanding to unlock their potential. Currently my energies are most efficiently spent unraveling the details of our local native plant species. In a horticultural sense this is a backwater of uncharted territory where there is very little interest (most likely none). It is certainly not for those that want immediate and certain gratification.

Having said this, I can grow and maintain first generation plants that produce viable seed (via sexual reproduction, not selfed or apomixis seed). It is in the following generations where progress will be made. Maintaining first generation plants is demanding, so in many ways I do not find this as progress.

At least I am making quick progress with other aspects of this project, mainly a detailed understanding of the physiology, breeding systems, and genetics of our native Viola species and some of our other local native species as well. I know this is boring stuff to most, but it floats my boat. 

[hamparstum]

<<It is certainly not for those that want immediate and certain gratification>>.
interesting comment...
Even with my 300 plus varieties of roses and quite a ways trodden with them, I hardly find that happening ever. Immediate almost never unless one buys a flowering potted plant. Certain is even harder if one grows them in this so well described changing climate :' ( but surprisingly still denied by some... ). So I deduce that it a matter of interest and conviction. I can only speak of myself. I just came in after pricking quite a number Lewisia seedlings ( L.cotyledon 'Regenbogen' series from Jelitto ), while my Howell's Lewisias were happily showing off my most unexpected very late bloom. When I first ventured into that genus I was told that they belonged to the "very difficult" category. So my motto is ignore what others tell me and just try it  by myself. Others may be right and I have failed in spite of following the best advice, but suddenly one hits right on the nail and part of the mystery is solved.
Arturo

[Robert]

Arturo,

I just came in from doing fire control all day at the farm. I have to admit that I am tired. At least it was not 100 F today. 

Thank you for your timely comments. I never want to discourage anyone as they pursue their gardening activities. On the contrary I hope folks are encouraged. I also realize that I am off on my own tangent. I had to make many mistakes before I found a system where some of our native Viola species thrive and set seed year after year. It has been a very slow process. Breeding difficult species adds to the challenges.

Castilleja species are very fascinating and beautiful. Others have already made progress cultivating them, however I am pressing forward to see what advancement I can make. I have been successful with both annual and perennial species. In our garden some of the perennial species can be long lived and excellent garden plants. I am out of the starting gate but that is about it.

What was once Mimulus (now Mimulus, Diplacus, and Erythranthe) has many beautiful species. Some of our local annual species are especially nice. Cracking the code and creating easier to grow garden plants has a number of challenges. So far I am only out 3 generations with some of the species, but through designed selection progress is being made. The going is slow, but this the way it goes. Preliminary results are already looking good. There are plenty of failures too.

None of this easy, but I find it enjoyable.

[Leucogenes]

Hello Arturo

I think your personal attitude to gardening work is very good...don't let yourself be discouraged and try it with supposedly difficult species. I feel the same way...of course there are always setbacks and losses...but partial successes compensate for it. 

Good luck on your further way...

Thomas

[Gerdk]

Concerning the cultivation of western violets (US) I would like to add some thoughts (albeit late) here.

I cultivate and have cultivated (Zone 7 b) a lot of North American violas. Those from the northeast are more or less easy if not weedy. Only Viola pedata is an exception and I would like to say nearly impossible to grow outside here.
Among the western species some of them are not too difficult - but inside a sunny greenhouse with protection against too much rain in summer and cold in winter. Examples are Vv. trinervata and its relatives (beckwithii, sheltonii etc.).
A lot of them, which I received by the generous help of Robert tend to be very tricky and it is a real challenge to explore their needs in cultivation. Being an optimist I always hope that once there will be a chance to find a provenance from a certain site which is better suited for cultivation than others - or, as Robert stated, there will be offspring of difficult species which is more adapted after some generations.
Generally I guess that western species would be an interesting addition to gardening but here restricted to countries with a similar climate as California. Unfortunately there are not as many enthusiasts around for the genus as for tender bulbs. Maybe this will change sometimes - everything is possible.

Gerd