Bullet Proof and Blingy! Holly-leafed Cherry - Another Excellent California Native

If you are one of those people that say growing California native plants is difficult, try the evergreen

hollyleaf cherry, Prunus ilicifolia ssp. ilicifolia. Read on, if you want to know why I think this is one of best plants for your garden. Looks are deceiving as this shiny-leaved, almost delicate-looking evergreen small tree is one of the toughest members of my plant posse. Check out these gorgeous leaves (Figure 1). Did I say blingy? Why yes, yes I did! Sparkly and blingy! I love this plant!

Figure 1 Prunus ilicifolia ssp. lyonii leaves                                                                                                                                  S. Reeve

Botanical Classification  

The genus Prunus is in the Rosaceae, and more specifically, the subfamily of Prunoideae, which is characterized by having one simple pistil with one superior ovary. Fruits are a stone fruit or drupe with one seed surrounded by a hard coat. The genus Prunus has flowers that are 5-merous, in other words, with five petals, five sepals, and other floral structures (stamens) in multiples of five (Figure 2). Flowers are arranged in a 2" long raceme with many flowers (Figure 2). Plants start blooming around three years of age in the late spring. 

  Figure 2 Prunus ilicifolia ssp. ilicifolia raceme of flowers                                                                                Marc Kummel

Evergreen simple leaves of Prunus ilicifolia ssp. ilicifolia are deep green, with a paler underside, around two inches long, alternate, oval to round, serrate with coarse spines and sometimes with wavy leaf margins, and very glossy (Figure 1). Cherry fruit ripens in the early fall and can range from red-to-black and sometimes yellow (Figure 3).

   Figure 3. Prunus ilicifolia ssp. ilicifolia fruit    

Prunus ilicifolia Subspecies Distribution and Characteristics

Prunus ilicifolia has two subpecies Prunus ilicifolia ssp. ilicifolia (Figure 4) and Prunus ilicifolia ssp. lyonii (Figure 5). For the ranges below I used Calflora maps and recorded the area where there were substantial populations. For the Baja populations, I relied on descriptions from the  Baja California Plant Field Guide by Jon Rebman. (I usually use Adobe InDesign to do page layouts and this is in Google Blogger and I have no idea how to get these maps to line up. Blogger just seems to do stuff for no reason). 

Prunus ilicifolia ssp. ilicifolia has a larger distribution. Hollyleaf cherry is found predominantly in coastal chaparrel, coastal scrub, and oak woodland ecosystems with scrub oak, coffeeberry, and toyon on both moist and dry slopes, up to 5000 feet in elevation, from Napa County down into the upper third of Baja California. Prunus ilicifolia ssp. ilicifolia is a generalist plant and further north it is found in a number of communities, including alluvial scrub and desert transition. In Baja, it occurs up to 1500 feet in elevation. Further south it occurs more on northern slopes and canyons that tend to be moister environments or near water. Growth habit of Hollyleaf cherry is variable and wholly dependent on the presence of water. Plants with rich well-drained soil near sources of water become tree-like while those in my arid situations stay small shrubs. Hollyleaf cherry attains the largest sizes in canyons with sandy moist soil. A few stragglers are found even further south than shown on the map but only in ideal conditions (Figure 4). 

Subspecies Prunus ilicifolia ssp. lyonii occurs predominantly on the larger Channel Islands, but also on coastal Southern California, and populations also exist in the central postion of Baja California (Figure 5). Prunus ilicifolia ssp. lyonii occurs at lower elevations, up to 1800 feet in elevation. How the populations got so far away from each other is a mystery. I wonder if native peoples moved Prunus ilicifolia ssp. lyonii from the Channel Islands to the mainland and down into Mexico?

                                                                                     

Figure 4. Prunus ilicifolia ssp. ilicifolia range                               Figure 5. Prunus ilicifolia ssp. lyonii range 

Prunus ilicifolia ssp. ilicifolia differs from Prunus ilicifolia ssp. lyonii in several different ways. Prunus ilicifolia ssp. lyonii, also called Catalina cherry, is a much larger plant, and definitely a tree (Figure 7).  The photograph in Figure 7 was taken on Catalina Island near Two Harbors in a location called Cherry Cove. As you can see these are trees that can get large, and eventually can attain 45 feet in height. The leaves are also quite different from Hollyleaf cherry, in that, there are no spines, and the margins are entire. Studies suggest, that in the absence of grazing animals, the island subspecies did not need to develop the evolutionary strategy of spines to thwart herbivory. The foliage is softer and less shiny and the margin is not wavy like most members of Prunus ilicifolia spp. ilicifolia. Catalina cherry also has larger fruit and longer petioles than Hollyleaf cherry. The bark differs as well, with Prunus ilicifolia ssp. ilicifolia having dark grey and smooth bark that becomes fissured with age, and Prunus ilicifolia ssp. lyonii having rough-seamed fissured bark that is colored dark reddish brown. Keep in mind these two subspecies hybridize readily, so it is sometimes difficult to distinguish if you have a straight subspecies in the field. 

     Figure 6. Prunus ilicifolia ssp. lyonii leaves

     Figure 7. Prunus ilicifolia ssp. lyonii trees at Cherry Cove near Two Harbors, Catalina

Ethnobotany

This topic has been covered very well in a number of publications and could be an article in itself. Suffice it to say, Hollyleaf cherry was very important to the coastal native people of California. I do want to add what I found when I was researching my senior thesis while earning my BA in Landscape Architecture. Hollyleaf cherry was originally called "Slay" by the Salinan tribe of California native Americans.  The name changed under Spanish influence to "Islay", and the name was widely used and incorporated into the Spanish vernacular of place names where Islay cherry trees abounded. In San Francisco, the Muwekma Ohlone Tribe, harvested the bounty of Islais Creek, for several thousand years. A population of Islay cherry trees thrived there in the Bernal Heights area of San Francisco (Figure 8). In San Luis Obispo there was "Islay Creek" and "Islay Hill." 

    Figure 8. Historical location of Islais Creek watershed in San Francisco                                                               unknown

Native Americans prized the shelled seeds of the Islay cherry more than acorns. Unlike grocery store cherries where the pulpy mesocarp is eaten and the pit thrown away, the pit of the Islay cherry is what was primarily eaten. Some tribes were reported to eat the flesh (Kumeyaay), but the flesh is relatively skimpy and not valued. In the records, various tribes had various methods for preparing the seeds for eating.  Cherry pits contain cyanogenic glycosides, specifically amygdalin and prunasin, which are converted in digestion to toxic compounds. When crushing the leaves, an almond smell can be detected which is evidence of prussic acid (prunasin) content in the leaves. In the watery environment of the digestive track these compounds break down to form hydrocyanic acids containing hydrogen cyanide (HCN) which are toxic in sufficient quantities. In food preparation, after removing the pulp, the seeds were shelled and either roasted, ground, boiled, leached with water, or a combination of treatments, to remove the toxins and the bitterness. HCN volatilizes readily when the seeds are dried or treated. Most native tribes used the mashed ground pits as a meal to make a cake, and some tribes, like the Kumeyaay, made a porridge. Sometimes it was sweetened, and often combined with pinole flour or grass seed to form a reddish cake, that was said to taste like beans.

Other ethnobotanical uses for Prunus ilicifolia include making a green dye from the leaves, and using infusions of either bark, roots, or leaves as cough medicine. The toxins act as a muscle relaxer and are also said to improve digestion in small amounts. Infusions were also used for headache relief and for an eyewash. The fine wood of cherry was used to make bows for hunting. One of the most important uses of the Islay cakes were for socializing with vistors. 

                           Figure 9. Prunus ilicifolia ssp. lyonii                                                                         S. Reeve

Prunus ilicifolia in the Landscape

I have Prunus ilicifolia ssp. lyonii in my landscape. After three years it is 7 feet high and 6 feet wide, from a gallon pot. This is its third year and I am seeing an acceleration of growth. It initially received regular water but no longer. This plant becomes more drought tolerant with age. The plant seems to be forgiving of watering errors. It takes summer water, which, for many California natives is a death sentence. The foliage is gorgeous, to a leaf, and it doesn't seem to have much insect damage. The plant I have is in light shade to full sun and the soil is fast-draining and rich sandy loam. I seemed to have hit upon the magic set of conditions. I am thinking it may bloom this year! The plant tolerates shade and full sun, but I think light shade is best here in San Diego. The plant seems to be long-lived with some specimens reaching 100 years. The shrub or tree is also very good at stabilizing slopes. 

This durable plant suits a wide range of landscape treatments. It makes a fine clipped hedge, a free-form mixed hedge with other native plants, a standard, or trained as a small tree. Bad views? Use this plant as a screen. The width can be maintained so it can develop height. Just be aware the fallen fruit stains concrete, so position it accordingly. Also, if size must be controlled, use hand trimmers to avoid the chewed up foliage look that results from powered hedge trimmer use. Training to a single trunk may require frequent trimming of root sprouts--don't say I didn't warn you! Prune in July. Young trees are not frost tolerant, but become increasingly so with age, down to zero degrees F. 

Although, this is an actual drought tolerant desert transition plant, it does look out of place with other desert plants. Next to Toyon, Quercus dumosa, Rhus intergrifolia, Frangula californica, or Sambucus would be more appropriate. An especially choice combination is with a red-tinted Arctostaphylos like 'John Dourley', 'Sunset', or Arctostaphylos pajaroensis. If the manzinita is trimmed to expose the peeling trunks the beauty would be showcased in front of the glossy green of the cherry. Nice!

Uses for Prunus ilicifolia ssp. ilicifolia are similar. It is said that a straight subspecies of Prunus ilicifolia ssp. lyonii no longer exists in the trade, and all have varying degrees of Prunus ilicifolia ssp. ilicifolia in their lineage.

Wildlife Gardening 

If you have a wildlife garden you must have this plant! A long list of organisms benefit from its inclusion in the landscape. Hollyleaf cherry can even be used in a highly urban garden to attract birds, bees, and other creatures. 

Flowers are highly valued for pollen and nectar, when blooming in April-May, by honeybees, and native bees in the genera: Ceratina, Habropoda, and Osmia. Native bumblebees (Bombus) also visit the flowers. 

A long list of Lepidoptera nectar on Hollyleaf cherry including Western Tiger Swallowtail, Anise Swaallowtail, and Pale Swallowtail, California Sister, Lorquin's Admiral, Red Admiral, California Tortoiseshell, Variable Checkerspot, Edith's Checkerspot, Brown Elfin, and Hedgerow Hairstreak and many others. Moths visit the plant for nectar at night. Many butterflies and moths have evolved to use the plant as a host plant. Butterflies include Western Tiger Swallowtail, Pale Swallowtail, Echo Blue, and Coral Hairstreak. A very long list of moths use Prunus as a host plant. Ants, flies, lacewings, and wasps all visit Prunus blooms. Beneficial insects all visit Prunus looking for prey.

The plant itself offers shelter or nesting sites for many species of birds like towhees, wrens, warblers, sparrows, finches, bushtits, juncos and quail. For some birds, though, the ripe fruit is the draw. Robins, finches, cedar waxwings, and towhees enjoy the fruit and spread the seeds. Woodpeckers visit to find insects. Small mammals, coyotes, and rodents eat the fruit. Leaves are browsed by deer, and bighorn sheep, although, maybe not in your yard. 

Propagating Prunus ilicifolia 

Fresh seed germinates easily if you remove the mesocarp (pulp) first. Collect the ripened fruit in early January (Betty Young), or when you see fully ripened fruit, could be in the fall. Cover fruit with water and mash the fruit to loosen the skins and allow to ferment for easier removal of the pulp. You can make this process easier if you get an old blender and wrap duct tape over the blades. Place seeds in blender and cover with water. Pulse to remove pulp, and allow to sit for several days so fermentation can take place. 
Here is a kitchen method to remove pulp, place fruit in the largest zip lock bag, and leave enough room for enough water and air, and put enough water to cover. Allow the bag to sit outside and ferment. You can squish the contents with your hands to hasten the separation of seeds. Alternatively, rub seeds over a screen to scrap away pulp- messy.  Remove pulp and plant seed as deep as the seed is large in tree tubes with planting mix. Otherwise, after removing pulp, thoroughly dry the seeds and store in the refrigerator. Stored seed will need cold stratification to germinate. Soak stored seeds in water overnight then place in baggie with moistened perlite and put back in the refrigerator. Seeds should germinate in 1-3 months. Remove germinated seeds and plant in tree tubes with planting mix.

If you do not have this plant in your yard and you call yourself a "wildlife gardener" you are committing a crime against nature. Go get it!

----------------------------I easily use 40-100 sources to research these articles-------------------------------

California Fairy Duster - One of My Favorite Plants - It Never Stops Blooming!

Figure 1) California Fairy Duster Calliandra californica                                                                    Desert Rivers Audubon

Location

California Fairy Duster or Baja Fairy Duster Calliandra californica is one of my favorite plants (Figure 1). There are several of these in my garden because it they are stellar performers. They seem to bloom all of the time! Going by the name, you would assume that this plant is from California, but you (and I) would be wrong. The species name, californica refers to Baja California and not our lovely state. The species is found in Baja California Sur, mostly in the upper regions of the Central Desert down to Santa Margarita Island (Figure 2) and a few populations are sprinkled in the Cape Region. This is a plant that can be found where water occurs in gullies, seeps, and washes, and is reported to grow on low alkaline hillsides. My references also list it occurring across the Gulf and further east into Sonora, Mexico.

Figure 2) Primary Range of Calliandra californica
Adaptation of Wikipedia map
https://upload.wikimedia.org/wikipedia/commons/thumb/9/9d/Baja_California_Sur_in_Mexico.svg/2029px-Baja_California_Sur_in_Mexico.svg.png

Botanical Classification 

The genus Calliandra is in the plant family Fabaceae and the name means "beautiful Botanical Classification   There are three members of Calliandra in Baja California and approximately 135 species (Kew) worldwide mainly in semi-tropical and tropical locations in the Americas. Two species were recently found in continental Africa, nine in Madagasgar, and two from India. Most species occur in Brazil, Mexico to Central America, and in Northwestern South America. Three species occur in Baja Calfornia and one occurs in the United States.

The Fabaceae is further divided into three subfamilies based on floral characteristics. Members in the Fabaceae fix nitrogen with species of symbiotic Rhizobium bacteria. Calliandra is in the subfamily Mimosoideae, which is distinguished by actinomorphic flowers, meaning that the flowers are radially symmetrical, and have five fused or separate petals. Other characteristics of Mimosoidaceae include straight fruit with swollen margins, which open explosively from the apex to the base. In the case of Calliandra californica, the five petals are fused at the base of each flower, and form a tubular-funnelform calyx shape with 5 lobes. The most striking characteristic of flowers is the long (17-25 mm) bright red stigma filaments that number 17-26 per flower. The flowers are formed in berry-like clusters of 8-12 flowers, that bloom simultaneously to form one large cluster of striking showy stamens (Figure 3). The leaves are bluish-green and evenly bipinnately compound with 5-15 pairs of leaflets. The leaflets close at night, by folding up along the mid rib. This response to darkness is also called nyctinastic closure or "sleep movement."  This movement is facilitated by anatomical thickenings at the base of plant leaflets called pulvini. Pulvini are common structural adaptations in the Fabaceae. In some species of Fabaceae the pulvini respond to touch, rather than light, in a process called thigmonasty or "touch movement." A well known example of thigmonasty is seen in Mimosa pudica or "sensitive plant." Like others members of the Fabaceae, seeds are contained in flat felty pods that open along the seam from the distal end and explosively eject seeds as far as 6 feet away from the plant. Spent pods remain attached to the shrub for an extended period.

Figure 3) Flower bud clusters and opened flowers of Calliandra californica                                           S. Reeve

Figure 4) Showy stamens and seed pod of Calliandra californica                                                                              S. Reeve

Calliandra eriophylla

Southern California does have a native Calliandra, Calliandra eriophylla or Fairyduster. In Spanish it is referred to as huajillo, cosahui, and English translations of other names are "Head of the Angel or Hair of the Angel." Eriophylla refers to the woolly leaflets. This rhizomatous, densely branched, unarmed species is smaller at 2-3 feet tall and 4 feet wide, and occurs in Creosote Scrub habitat in eastern San Diego County and Imperial County. It is frequently used in erosion control. Calliandra eriophylla is deciduous in drought or in excessive cold conditions. Its large range extends into Arizona, Texas, Baja California, and Sonora, Mexico. Calliandra eriophylla is drought tolerant and survives on 3-9 inches of rain a year. In my garden, this plant does not seem to bloom as long as Calliandra californica. References list the bloom period as late winter to early spring, although, further reading says additional water can boost the bloom period into early summer. Fall rains will frequently result in an additional bloom. The stamen color varies and can be white to pink to red (Figure 5). My experience with the plant is at odds with the text. I find the leaves are greener than the bluish-green leaves of Calliandra californica. Fairy Duster is root hardy to 5 degrees F and slightly more cold tolerant than Baja Fairy Duster. This plant needs some selective pruning to keep it looking its best. Removal of twiggy growth and shaping will bulk up the airy nature of this shrub. Both species look better with heavy pruning after damaging freezes.

Figure 5) Calliandra eriophylla                                                                                                    Paul Asman and Jill Lenoble

Description Calliandra californica 

I love this plant! The overall shape is a pleasing vase shape even without pruning (Figure 1). Some reference texts talk about how slowly this evergreen shrub grows, and again, this has not been my experience. I have one in the ground that is full height in less than a year, but I suppose it is in an above average situation, and this may not be the normal growth rate. This evergreen shrub matures at 5 feet tall and about 6 feet wide. Other texts refer to Calliandra californica as having a "fast" growth rate, and the difference I think is in the situation the observed plant is in. I believe that in desert-like conditions with full sun, fast drainage, and drier air the plant is faster than in coastal situations with less heat and sun. Well-draining soil is better for good growth, but the plant is adaptable. In my slightly inland garden it has been fast, and I am sure the supplemental irrigation helped! I find the foliage is a very pleasing steel bluish-green that I find lovely juxtaposed with the bright true-red stamens. My plant has bluish foliage and I assume there is a natural range of foliage color from bluish to deep green. I have some plants in full sun and some in light shade and they are all covered in blooms.

Selections and Hybrids

Sarita™ 

A selection of Calliandra californica was made and a patent was filed in 2008 and approved in 2009. It was the result of a mutant seedling that had a strongly prostrate habit. The trademarked name is Sarita™ and also referred to as Calliandra 'Cascada Desiertica (not a misspelling).  The plant height is listed as 30 cm and width 1.5 meters, so about 12 inches tall and 5 feet wide. The selection was made by Sarah Celestian working at Desert Tree Farm in Phoenix, Arizona.

Sierra Star®
Calliandra x Sierra Star® PP15387 is an especially floriferous hybrid between Calliandra californica and Calliandra eriophylla made in 1982 by Ron Gass of Mountain States Nursery. It is also referred to by the variety name of 'Lianca.' It is said to be slow growing, but worth the wait (Figure 6). I don't know about you, but this plant is just lovely and I can see installing it in many places where turf used to exist. Just perfect with boulders beside a dry stream bed! I can see it mixed with blue agaves, Opuntia basilaris, Encelia farinosa, and a 'Desert Museum' Palo verde. Because of the Calliandra eriophylla blood it is lower growing, at around 4 feet high and wide, and suitable for more garden situations than straight Calliandra californica. What is notable about the cross is the bright red stamens of Calliandra californica have been retained. The plant is deciduous below 30 degrees F and said to be hardy down to 15 degrees F. My references claim that Sierra Star® is more cold tolerant than Maricopa Red®.

Figure 6) Calliandra x Sierra Star ® PP15387                                                                                Mountain States Nursery

Maricopa Red®

Calliandra x Maricopa Red® is another cross between Calliandra californica and Calliandra eriophylla (Figure 7). The hybrid was made by Civano Nursery of Tucson, Arizona. From what I have read, this hybrid is slightly shorter than Sierra Star®. The blooms of Maricopa Red® are also pinker than Sierra Star®.

Figure 7) Calliandra x Maricopa Red                                                                                                              Civano Nursery

Wildlife Value

This is always my favorite part when I get to talk about the wildlife you will attract with these plants. It makes me absolutely giddy with anticipation! My plants are favored by hummingbirds (of course!), and unlike many red blooms, are also heavily visited by honey bees Apis mellifera (Figure 3) . Hummingbirds favor these plants over hummingbird feeders since they are high in sucrose with 22-26% concentrations. I also see occasional Monarch butterflies on the blooms. Investigation into other reports find that the plants are also pollinated by flies, additional species of butterflies, like the Marine Blue, Inchworm and Owlet moths, and Carpenter bees (Xylocopa species.) Biologist, Jeffrey Allen Caldwell in his publication, "California Plants as Resources for Lepidoptera: A Guide for Gardeners, Restorationists, and Naturalists" reports that Cloudless Sulphur, Southern Dogface, Monarch, Ceraunus Blue, and Marine Blue all nectar on Calliandra californica. It is also a host plant for Ceraunus Blue and the favored host plant for Marine Blue butterflies. Jeffrey reports that Calliandra eriophylla is visited for nectar by Swallowtail species, and other large butterflies, Imperial Checkerspot (B. J. Stacey), Mormon Metalmark (B. J. Stacey), and Fiery Skipper.

Studies show that the flowers are heavy nectar producers. This is probably why I see Argentinian ants all over the blooms (grrrr). The pollen is transferred to other flowers by pollen packets, called polyads, that stick to pollinators on the their way to another bloom. Each pollen packet is a composite made of at least eight assymetrical pollen grains. An example of a Calliandra species polyad is in Figure 8 it is from Calliandra bahiana var. bahiana from Brazil. One study of moths found Calliandra pollen was mainly found on moth proboscis and also on eyes, legs, and antennae. Bats also feed on Calliandra species.  The seed of the plants are eaten by several species of quail: Gamble's, Bobwhite, Scaled, and Mearn's. Other small birds will feed on the abundant nectar such as warblers, finches, verdins, wrens, orioles, and gnatcatchers. The Calliandra species discussed are unarmed and also browsed by deer and other mammals. The dense twiggy growth offers a cover source for small animals and a nursery for baby plants. So besides looking awesome in the garden, this plant feeds lots of creatures!

Ethnobotany

Studies I read list that Calliandra californica has been valuable for resolving urological problems, and possibly for diabetes treatment, specifically because it contains diterpenes called Escobarine A and Escobarine B. One study found they have antibacterial properties. Another study finds the diterpenes have antituberculosis and cytotoxic activities. Escobarine A specifically displays anti-cancer activity. Historically, the roots of Calliandra californica were used to dye leather red. Decoctions were used in folk medicine to treat cystitis, kidney ache, urethritis, prostate inflammation, cramps, fever, and toothache.

 Figure 8)         Francisco de Assis Ribeiro dos Santos and Claudio de Oliveira Romao

Propagation

Both species readily cross. You might want to be aware of this when you see seedlings. I have not actually propagated this particular genus, BUT, I have propagated many plants from seed and cuttings, and can tell by published propagation techniques what may work and what probably won't. My intuition is pretty good. Working from several sources, I have boiled it down to the following information.

The plants propagate easily from seed, but rot easily after germination. Now we all know after reading how explosively and unexpectedly the seed pods open and expel seeds. Small drawstring cloth bags can be tied around the maturing seed pods to capture rocketing seeds. As for the problem with rot, this can be addressed with a combination of modification of methods. 1) Improve soil media so it naturally combats pathogenic fungus, by inoculating with organic compost and mycorrhizal fungi. 2) Improve air circulation by placing pots outside or under fans. 3) Bottom heat or waiting until it is warmer in the year, will decrease the possibilty of rot. 4) Plant directly into potting media and bypassing a sterile seed starting mix.

I worked for awhile propagating plants and really thought about the soil mix. I don't believe sterility is good in every circumstance because once a pathogenic fungus floats into the greenhouse from outside, and it always does, there is nothing in the soil to combat it. You are essentially starting seeds in dead soil when it is sterile. Now this may fly in the face of how propagation is normally done, and certainly sterility is required in some situations, but I also believe in the power of biodiversity to solve problems. Additionally, studies have shown improved root growth in soils with good microbiota.

Trish Meyer from Wildscaping suggests the following soil recipe:

* SunGro's Sunshine #4 soilless mix (fast-draining, comes with fertilizer mixed in, reasonably priced by the bale)

* Time-release fertilizer 

* Organic transplanting fertilizer with mycorrhizal beneficial fungi (EB Stone Sure Start)

* A dollop of home grown organic compost

Maybe someday I will try it, but my best guess on how to propagate this plant is to capture the seeds in cloth bags, plant in late spring or summer, plant in deep small pots (rose pots), place outside.You could also try using bottom heat and fans in the greenhouse.  Other protocols have mentioned nicking the seed coat or scarification which couldn't hurt, but may be overkill. They also mention tip cuttings with IBA as a potential propagation technique, and layering using flexible stems.

My Worst Weed has Genius Survival Skills

My Worst Weed has Mad Survival Skills

I became intrigued about the mad skills my-most-hated-weed has and decided to research them and share with you how amazing this plant is, in terms of doing its best not to ever die! The common name is Benghal dayflower or Commelina benghalensis, and it is in the Commelinaceae family. Commonly known as tropical spiderwort and other non-politically correct names, like wandering Jew. It sure does wander and it wanders fast! Any moisture will necessitate rampant lush growth that will quickly cover other plants (Figure 1).

Figure 1.           Commelina benghalensis                                                                                                                  S. Reeve

Commelinaceae Family

The Commelinaceae are annual/perennial herbs with succulent stems and swollen nodes. The family is named after a Dutch botanist, Caspar Commelijn, 1667-1731. Worldwide, there are approximately 170 species, with the majority originating in Africa and tropical Asia. The family is characterized by leaves that spiral around the stem, each leaf forming a closed sheath around the stem (Figure 2). The above-ground flowers are hypogynous, with the ovary above floral structures. The corolla (C), or petals are ephemeral and occur in threes, and are either blue or white in color. An evolutionary novelty of this family is the presence of 3-celled glandular microhairs, which are really tiny hairs, for lack of a better term, and invisible to the naked eye. The term glandular means they produce some kind of secretion; although, I could never find out the identity of the secretion. The hairs are thought to reduce herbivory and transpiration, and are sunlight-reflecting, thereby, decreasing moisture loss.

Figure 2. Leaves sheath stems completely
Image from Invasive.org, Herb Pilcher USDA

Commelina benghalensis

This monocot was a recent arrival to Southern California in the eighties. As the common name dayflower suggests, the above ground flowers are open during the day (Figure 3). Commelina benghalesis is closely related to Commelina communis or asiatic dayflower. It is difficult to tell them apart at first glance, but they differ in that Commelina benghalensis is hairy, the flowers are a lighter blue color, and the plant has underground flowers (more on THAT later), and longer leaves. All members of the genus Commelina have bilaterally symmetrical flowers with three fertile stamens, three staminodes, and a reduced lighter-colored anterior petal (Figure 3).  

 Figure 3. Commelina flowers                                                                                                                                     S. Reeve

Survival Skills

This is the good part when we get to talk about the terms cleistogamous and chasmogamous flowers! This is one of the most difficult plants to kill for a number of reasons. Because of its succulence and its various evolutionary strategies for reducing water loss, you can pull it and throw it nearby, and it will remain viable until it rains, at which point, it will quickly send down roots. For this plant, I must either pull it and throw it onto the concrete, or bag it and throw it away (the loss of biodegradable plant material kills me). So for these reasons alone it is difficult to kill. Secondly, it is stoloniferous and it grows and roots at the nodes (Figure 4). Studies found that the rate of stem elongation, and branch and leaf formation increases as the number of nodes increases, so it directs it resources to the larger and more successful growth areas. This is truly a well-adapted plant for survival! It flowers at the nodes too, and each flower produces seeds. Additionally, in periods of low rainfall, the plant curls its leaves and the leaves take on a grey color to wait it out until it rains. Plants can remain in this torpor state for a remarkably long time! Typically an annual, with periods of high rainfall it can become a perennial, so it is highly adapted to survive.

This plant can also reproduce either sexually or asexually, increasing its chances for survival.  To reproduce sexually, it produces aboveground flowers during times of environmentally favorable conditions (Figure 3) . This reproduction scheme forms pollen-producing chasmogamous flowers (most flowers are chasmogamous). Chasmogamous means "open marriage." Chasmogamous flowers take more plant resources and energy because they are larger and more complex, with nectar guides, and other features, to attract pollinators. In the case of Commelina benghalensis, the elaborate, but pollenless, stamenodes serve to visually attract pollinators because they appear to be loaded with pollen. Bait and switch--so underhanded! 

Commelina benghalensis is also considered to be andromonoecious meaning that it produces both male and bisexual flowers on the same plant. This floral strategy is thought to promote cross-pollination. 

During difficult environmental conditions, it is less energetically taxing for the plant to also produce cleistogamous flowers. Cleistogamous means "closed marriage." For Commelina benghalensis, cleistogamous flowers are very small bisexual flowers, produced underground, that do not require pollination. The ratio of chasmogamous/ cleistogamous flowers is related to environmental conditions.  Studies have found that the underground seeds that form are highly persistent and can remain viable until conditions are right for germination. The subterranean seeds differed from the above-ground seeds in that they required higher temperatures, and more light to germinate. All I know is when I pull it those belowground seeds break off in the soil and germinate quickly. 

Figure 4. Rooting at nodes                                                                                          S. Reeve

The Deck is Stacked

Clearly, if it came to a battle of survival, at the end of the world there will be cockroaches and Commelina benghalensis! Couple all of its mad survival skills with the fact it has few predators or disease, and it becomes a wonder why I bother to battle it at all! In crops it is also a serious pest because it is immune to glyphosate. 

Sometimes I become a little smug and think I have a chance to win this war, and I have only to look across the fence into the neighbor's yard (Figure 5) to realize I don't have a prayer against Commelina benghalensis!

Figure 5. Neighbor's yard                                                                                                                                           S. Reeve

References on request

Silent Spring in China and USA - Let's Lose the Lawn

I was just reading in ASLA that Under the Dome is a new Chinese documentary film that exposes the extent of environmental pollution crisis in China. Reviewers call it to China's version of "Silent Spring." The fact-based documentary points to a corrupt government for turning a blind eye and a taking a weak stance where environmental laws are concerned.

After I read it I wondered, why are we pointing fingers at China when we are causing environmental destruction of an unprecedented scale in this country? I guess because we can say our heightened regulations have made our air cleaner than China's air, but what about our water and soil?

Harbin City in China                                                            Photo from Reuters

At least China does not allow GMO food while the United States does. GMO crops were engineered to withstand massive amounts of herbicides compared to traditional crops. Glyphosate, is one of the ingredients in most herbicide formulations, and may be not the most toxic ingredient, but certainly the most studied one. Recent studies have found that glyphosate is a "probable carcinogen" because of tumors and mutated cells that form in mice and rats after exposure. In our country, Monarch butterfly populations (90% less from the Xerces Society) and numbers of songbirds have plummeted, some species by 94%, since these crops have been grown. I am not suggesting a straight cause and effect, but clearly we are doing things wrong environmentally and GMO crops are contributing.

Neonicotinoid use on hundreds of millions of acres of US croplands have also affected honeybee, insect, and native bee populations. Once these chemicals run off into soil and streams they kill invertebrate populations, which are the base of the food chain for all animal life in this country.  China may be a disaster environmentally but WE are also having a Silent Spring here in the United States. The film questions the protection the Chinese government has given its people. When will OUR government protect the health of our natural resources and its people?

What can we do besides throw our hands up in despair?

We can do something.

Think about what typical suburban landscapes look like. Most contain lots of lawn and trimmed, non-blooming and non-native shrubs (see below). There is not much here of any value for bees, butterflies, or any organism that needs nectar and/or pollen to live. Birds would have a difficult time too since the insects they need in the spring to feed their babies are not here. There is cover here, to be sure, but not the cover native birds evolved with, and these are not the plants they need to thrive. Our birds, our bees, and our native plants species evolved together, and are closely linked. By not planting natives or high wildlife value plants, the reproductive fitness of subsequent generations of birds, bees, and butterflies will suffer.

Wildlife Wasteland

It also goes both ways.

As native bee populations dwindle, so do certain native plants that require specific species of bees to pollinate them in order to produce seeds. Take, for example the specialist squash bees, in the tribe Eucerini, Peponapis pruinosa and Xenoglossa spp. These bees are efficient pollinators of members of the squash family or Curcubitaceae. Widespread collapse of pollinators makes us in danger of losing some native plants to extinction. Ecosystems are a series of interconnected species and when you remove a species or severely impact it, other species will always suffer through either direct or indirect ways.

Peponapis pruinosa on squash                                                                                                                   Photo by Sharon Reeve

A paper by Cristina Milesi et al. 2005 estimated there is potentially 40,475,860 acres of lawn (163,800 sq. km) in the United States. It is estimated by the U.S. Census that 1.6 million new homes are added, on average, per year. A national gardening survey by B. W. Butterfield in 1999 found 47% of households had lawns. American Housing Survey found an average lot size of 5,227 ft2 in urban lawns, which are the smallest size compared to suburban lawns and lawns of larger country homes. Using this smaller estimate, we can extrapolate that if 1.6 million homes have been added per year since 2005, then in 2015 we have, conservatively, 41,378,496 acres of lawn in the United States. According to the EPA, in 2012, 914 million acres, of land in the U.S. is farm land. Farm land acreage is trending down, while home development acreage is trending up, so these figures are easily greater for the lawn acreage.

The size of our collective lawns makes up an 18th of the size of our farmland. It is difficult to grasp just how big almost 50 million acres of lawn is and just how influential it could be to saving our native flora and fauna. I can kind of visualize one to ten acres, but 50 million? It is hard to wrap your head around a number that big. In square miles this is 78,125 square miles which is roughly the size of the State of Minnesota.

Total lawn area in the US is roughly the size of Minnesota

To give you some idea on the value of native plants, Doug Tallamy, a highly respected entomologist from UC Delaware did an informal study in his backyard comparing two species of trees. This is a small study of n=2, that was repeated for verification, but the results are compelling, and make an excellent case for substituting natives for non-native plants. Dr. Tallamy counted the number of caterpillars at head height on a native white oak and a non-native Bradford pear of roughly the same stature. The next day he repeated the experiment with two new trees, again a white oak and a Bradford pear. The experiment was simple but the results were astounding! He found, on average, 321.5 species of caterpillars on the the oak while only one on the non-native tree. I trust the veracity of his data, even on small relaxed studies such as this because he has authored many other more formal, and statistically robust scientific studies.

It is well documented how valuable native oaks are to many species of wildlife. They seem to trump all other plants in the scope of species they support, whether through sustenance, or through providing sites for lodging, or nesting. In my own backyard I have one 25 year-old native live oak, Quercus agrifolia. I have many other larger and non-native trees. I am always astounded by how the birds all seem to chose the oak. Just the other day, I saw a Nuttall's woodpecker pecking the bark, many hummingbirds hawking insects among the branches, and a pair of bushtits busily constructing their hanging nest. I saw all of this within 5 minutes. There is no such comparable activity in my non-native trees. Oaks create their own ecosystem.

This brings me to the main point of my ramble, if you want to help correct the downward spiral of species loss in the United States--lose your lawn. Here are some photos demonstrating how much more visually interesting, and certainly more active with wildlife, the front of your house could be when planted with native plants.

Before Natives

After Natives

Theodore payne Garden Tour 2015

Garden by Stephanie Blanc                                                                                                             Photo by Steve Gunther Sunset Gardens

Waterwise Landscapes

LA Times Blog

These examples are all typical urban or suburban front yards, and while not all of the plants are native, most have value that offers something to wildlife in the garden beyond a trimmed monoculture of lawn grass. Unlike lawns, and to compound the benefits of planting native plants, they typically require less water and zero chemical inputs. Ideally, the most benefit comes from a palette of locally abundant native plants that are found naturally in wild places nearby. Imagine the difference we could make if every yard in America had at least one locally found native plant! My new slogan is, "A Native Plant in Every Yard." Or better yet, "A Native Oak in Every Yard!"

Together we can make it happen by losing our lawns. Together we can bring back the wildlife.

Coffeeberry - Frangula californica

   

Umbels of tiny flowers

Few California native plants are as versatile as the California coffeeberry. The shrub grows naturally in a neat shape that looks like the work of skilled gardener, so it is appropriate in formal or informal garden designs. Several selections of Frangula californica exist that vary in size from ground cover to large shrub, so there is one for every garden! The shrub is versatile too. It grows in either sun or shade, and naturally occurs in wide range of habitat types along the western side of California at elevations below 3,500 feet. It is found in alkaline soils in coastal sage scrub, chaparral, and in oak woodlands, and mixed-evergreen forested areas throughout the state, and extending up into the Siskiyou Mountains of southwestern Oregon. In Southern California the shrub is limited to coastal areas with greater water availability and less summer heat.

Description
In full sun, coffeeberry is an evergreen large mounding shrub, from 6-15 feet in height and equally as wide. In shade, the growth habit is more open and sprawling. Alternate oval leaves, that are 1-3 inches long, grow on reddish-tinged flexible branches and petioles. Leaves on coastal plants tend to be thin, and green on both sides of the leaf. Leaves of more arid location shrubs are thicker, curl under at the margins, and are often whitish and hairy underneath to conserve moisture. The green of the leaves is unique and almost a flat blue-green, with some plants having a blackish-green cast. Leaf midribs are strongly raised and the veins curve at the margins towards the leaf tips. New growth twigs and petioles are highly colored.

Raised midrib and curving veins

Wildlife Gardening
Tiny greenish star-shaped flowers in umbels of 5-60 flowers are relished by bees, flies, butterflies and visited by hummingbirds. Ripened fruits are devoured by many bird species. Coyote and deer also eat the fruit. The fruit is a drupe containing, most commonly, two seeds, with the subspecies, occidentalis, having three seeds. Fruits of various colors, from yellow to red to purple/black can be found on the shrub at one time, giving it a festive appearance, almost like multi-colored Christmas ornaments. The shrub is also the host plant for the larvae of Pale Swallowtail butterflies. My blooming coffeeberries are very popular with non-native honey bees, but they are important for native bees as well, one study found six native bees species visited the plant. If wildlife gardening is your focus, this plant should be at the top of your list.

Multi-colored fruit

Honeybee on flowers

Subspecies and Genus Changes
California coffeeberry was recently changed from Rhamnus california to Frangula californica because of new DNA evidence. Recent findings support genus Frangula as a monophyletic genus. The genus Frangula differs from the genus Rhamnus as it has five-petaled flowers, buds without bud scales, alternate leaves, and spineless branches. Rhamnus has (but not always)
four-petaled flowers, bud scales, alternate OR opposite leaves, and branches with spines. Coffeeberries share allegiance in the Rhamnaceae family with Ceanothus. Frangula californica has six subspecies listed in CalFlora with Frangula californica ssp. californica occurring coastally, and other subspecies in more arid or in serpentine (ultramafic) soils that are low in calcium and rich in magnesium and iron. In San Diego County the subspecies Frangula californica subsp. tomentella is more common inland. The underside of the leaves of this subspecies are covered in fine, soft whitish hairs (tomentose). This hairy adaptation slows water loss in transpiration by retarding the movement air across the leaf surface. Strict classification of the plants is complicated by common occurrence of interbreeding throughout the state.

Ethnobotany
Chumash Indians of Southern California used the aged bitter bark and berries of Frangula californica for purging and as a treatment for constipation. Major chemical constituents of the plant are anthraquinone glycosides, which are a class of phenolic compounds that work by increasing the action of smooth muscle in the large intestine. The Ohlone and Kumeyaay peoples used the leaves for poison oak dermatitis. The fruits were eaten fresh and raw or sun-dried by some tribes, while other tribes considered them toxic. Kawaiisu Indians used the leaves, berries and sap to staunch bleeding and to heal infected skin wounds.

Propagation
Coffeeberry is easy to propagate by fresh seed. Dry seed requires cold stratification. Collect mature fruit, identified by the deep black color, in the summer through fall and squeeze out the seeds from the pulpy fruit. Depending on the subspecies, individual fruits will have 2-3 hard brown seeds. Soak cleaned seed up to 24 hours and plant. Cotyledons will appear in 4-6 weeks. The germination rate is very high for fresh seed, although, the plants grow slowly once they have sprouted. Keep in mind that plants from named cultivars may not come true from seed.

Cultivars
Several cultivars for the coffeeberry were developed. I grow a native species (probably subspecies californica), and two cultivars, 'Eve Case' and 'Leatherleaf.' After three years in my garden in full sun, 'Leatherleaf' is about 3 feet high and 5 feet wide. 'Eve Case' has a more scandent, open habit and is a little taller at 4 feet and 5-6 feet wide. The native coffeeberry in my garden is easily 6 feet tall and wide and flowers more heavily. This is probably because it is this plant is in a slightly shady place with richer soil that gets more irrigation.

'Eve Case' 

'Leatherleaf'

According to the books I consulted, 'Seaview', and 'Little Star' have low dense growth that is very controlled and lends itself to a neat formal gardening style. 'Mound San Bruno' is dense but matures taller at 5 feet. When used as a foundation plant, the regular forms of this plant juxtapose well with more exuberant California natives as a place to rest the eye. Larger cultivars, mentioned previously, are 'Eve Case' which grows to 8 feet tall and 'Leatherleaf' which matures at 5 feet. 'Leatherleaf' has especially dark green foliage and is used effectively as a foil against white or gray-foliaged native plants like Artemisia californica 'Canyon Gray.' These plants lend themselves to pruning, if necessary, and can be used as an informal screen or hedge.

Care
Though considered semi-drought tolerant, in San Diego, coffeeberry would like supplemental irrigation. Ideally, 25 inches of rainfall is best for this plant. Mulch and a little shade would also benefit this plant further from the coast. Coffeeberry is best in well-draining soil and can tolerate more irrigation than other California natives, especially if planted in faster-draining soils. Moist, clay soils are problematic for this plant. It is reassuring to note, that after a fire, these plants resprout quickly from dormant buds in the root crown. Rangy growth can be pruned back with no problem.

The books says coffeeberry blooms in summer, but in my garden, they are blooming now on the first day of Spring and are covered in honey bees and flies. Many people who visit, comment on the profusion of birds in my garden and it is because I plant shrubs like the coffeeberry. Happy Spring!