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Friday, October 5, 2018

Plant of the Month (October) : Laurel Sumac – Malosma laurina


Laurel sumac (Malosma laurina): Mother Nature's Pollinator Garden

 
Southern California is home to an array of remarkable native shrubs. Many are more drought-tolerant than the non-natives commonly used in local landscapes.  In addition, the natives have interesting and useful attributes that make them welcome additions to the garden.  One such shrub – if one has the space – is our plant of the month, Laurel sumac.  The scientific name is pronounced mal-OZ-muh   low-RINE-uh.

Laurel sumac is a member of the Anacardiaceae (Cashew) Family, which includes such well-known S. California species as Fragrant sumac (Rhus aromatica [Rhus trilobata]), Lemonadeberry (Rhus integrifolia), Sugarbush (Rhus ovata), and Poison oak (Toxicodendron diversilobum).  The family also includes Pistachios, Cashews and the non-native Pepper Trees often used in S. California landscapes. For more on this interesting family see: http://mother-natures-backyard.blogspot.com/2014/12/plant-of-month-december-lemonadeberry.html.

Malosma laurina grows from Fresno and San Luis Obispo Counties south to Baja California, Mexico.  In Los Angeles County, it can still be seen growing wild on Santa Catalina and San Clemente Islands, in the Santa Monica Mountains, San Gabriel foothills, Verdugo Mountains, on the Palos Verdes peninsula and in other undisturbed places.  Laurel sumac’s distribution is limited primarily by its frost-sensitivity.  In past times, orchardists used this plant as an indicator of frost-free zones – places to plant crops such as citrus and avocados. [1]

Laurel sumac (Malosma laurina): Palos Verdes Peninsula

Laurel sumac usually grows on dry ridges and canyons below 3000' in chaparral and coastal sage scrub.  It’s occasionally found in S. Oak Woodlands, but only where frosts are rare.  Common associates are Black, White and Purple sages, California sagebrush, Toyon, Lemonadeberry, Sugarbush, Bigberry manzanita, California encelia and the Goldenbushes (among many others).

Laurel sumac was first collected in San Diego County in the 1870’s by Daniel Cleveland and Edward Palmer.  It was more widely collected in the 1880’s and 1890’s by such notable California plantspersons as the Parish brothers, the Brandegees, Blanche Trask and J.H. Barber.  The species was first introduced into cultivation by Theodore Payne. [2]   For more on these early collectors see: http://mother-natures-backyard.blogspot.com/2018/05/californias-fascinating-native-plants.html

Laurel sumac (Malosma laurina): growth habit

Laurel sumac is a large shrub or multi-trunked small tree.  At maturity, it reaches heights of 10-15 ft. (3 to 4.5 meters) and diameters of about the same.   In favorable locations, a plant can be as much as 20 ft. tall and wide.  The overall shape is rounded to slightly sprawling.  In the wilds, Laurel sumac can create thickets in favorable sites.  This is likely due to seeds falling near parent plants.

Laurel sumac (Malosma laurina): branches

 

The trunks and branches are substantial, and like Toyon and Lemonadeberry, the wood is moist and rather fibrous.  The bark on young stems is red-brown; it becomes an attractive pale gray-brown on older branches.  The shape and bark color make this a good alternative to Oleander, Photinia, Pittosporum and Xylosma. 

Laurel sumac (Malosma laurina): young leaves

 

One of the best reasons to plant Malosma laurina is its year-round interest and color.  Laurel sumac is evergreen, a characteristic prized in and of itself.  But  ‘evergreen’ scarcely does justice to the variations in leaf color typical of this species.  Young leaves and branch tips are a brilliant red/orange (above), due to anthocyanin pigments that protect from herbivory and sun-scald. This red color is often retained on the edges of mature leaves.  New leaves are produced year-round, even in summer/fall.   

Laurel sumac (Malosma laurina): mature leaves

Mature leaves are somewhat leathery, medium to dark green and folded along the midrib like a taco shell (see above). The leaves are medium to large – four to six inches in length.  The leaf shape is simple and reminiscent of the leaves of the Laurel – hence both the common and scientific names.  Senescent leaves turn yellow (below) adding to the colorful foliage in this species.



Laurel sumac (Malosma laurina): senescent leaves

All parts of Laurel sumac are pleasantly scented. The flowers and sap are aromatic, and the leaves release scented, volatile chemicals into the air.  On a warm or wet day, the characteristic aroma can be smelled at a distance. Even fallen leaves release the aroma when walked upon.  For more on gardening with scent see: http://mother-natures-backyard.blogspot.com/2018/03/gardening-for-health-2-magic-of-scent.html

The scent is a unique blend: bitter and somewhat fruity.  It’s been described as the scent of bitter almonds, unripe apples or citrus.   It’s an aroma unique to the plant, and for many, it’s the ‘scent of the California chaparral’.   As a note of caution, some people have nasal allergies to the plant chemicals and/or pollen.   In addition, the sap can cause contact dermatitis (short-term skin allergy) in sensitive individuals.  Gloves should be worn when pruning or handing the plant.

Laurel sumac (Malosma laurina): flower buds


Laurel sumac (Malosma laurina): flowering plant


Malosma laurina blooms most often in late spring or early summer.  In the Gardena Willows Wetland Preserve (where our gardens are located) it commonly blooms in June or July.  This is quite a showy bloomer.  The flower buds are a pleasant pink that contrasts nicely with the spring leaves.  The flowers themselves are creamy white.  The flowers grow in dense clusters at the ends of the branches (above).  The look reminds one of a lilac bush with white flowers.
 
Laurel sumac (Malosma laurina): close-up of flowers

 

The flowers themselves are small, simple, with five rounded petals.  The flowers can be either bisexual or unisexual (see photo above); in at least some cases, plants can be functionally either male or female.   The details are currently being studied, so we’ll know more about the reproductive biology of Laurel sumac in the future.  The interested reader is directed to ref. 3 (literature) for more on this fascinating topic.

Laurel sumac (Malosma laurina): ripening fruits

 

The flowers attract European Honey bees, native bees, pollinator flies and likely other pollinators.  The fruits are small and not particularly showy.  They start off green and are white when ripe.  The dried fruits, which are dark brown, remain on the plant into fall and winter. The dried fruits add fall/winter interest (see below).  The fruits and dried seeds are eaten by a number of seed-eating birds, but are particularly loved by song birds.   In fact, this species provides good bird habitat: food, perches, shade and nesting sites.

Laurel sumac (Malosma laurina): dry fruits

 

Malosma laurina takes a year or two to establish, then it grows to size fairly quickly thereafter.  In the wilds, plants can live at least 30-45 years.  The actual age limit is difficult to determine.  Plants burn to the ground in a fire.  But an underground sprouting root (lignotuber) remains alive, allowing plants to re-sprout quickly (often the first green seen after a fire).  So, the age of a mature plant may be older than the age of a single trunk.

Laurel sumac needs full sun and prefers well-drained soils, with a pH 6.0-8.0.  It does well on slopes (as it does in the wilds).   It is intolerant of low temperatures and pH much above 8.0.  The plants are relatively insect-resistant and do best when leaf litter is allowed to accumulate (this is true of many chaparral shrub species).   The plant can be pruned up as a small tree, and yearly fall trimming will keep it from getting rangy.   Old shrubs can even be cut back hard (even coppiced) to rejuvenate them.

Once established, Laurel sumac is quite drought resistant. Plants have roots that grow deep – 40 feet or more in some cases.  Mature plants get by on occasional to no summer water (no more than one deep watering a month).  But they do need adequate winter/spring water, so supplement as needed.  

Laurel sumac (Malosma laurina): mature plant,
Heritage Creek Preserve, CSU Dominguez Hills, Carson CA

 

Future climate change may prove challenging to this species.  Several of us have noted branch die-back in established plants (see above).  Early research suggests that this is due to fungal disease, and some individuals seem to be more susceptible than others. As with many local plant disease/pest problems, drought stress appears to be a contributing factor to susceptibility.  For more on this topic see ref. 4, below.

Laurel sumac (Malosma laurina): at home on the
 Palos Verdes Penninsula

 

Malosma laurina is a great choice for slopes and for wildland interface areas.  If planted in areas prone to wildfires, it should be planted away from structures, and the lower 1/3 of small branches removed.  Laurel sumac makes a great background plant, with its evergreen leaves and flowers.  It looks particularly good when paired with its natural associates: the plants of the S. California coastal sage scrub.

Like Toyon, Laurel sumac is quite versatile.  It can be pruned up as a small, multi-trunk tree or used as a hedge, screen or hedgerow.  As a hedge, it can be pruned formally or informally.  If space is limited, Laurel sumac can even be espaliered along a wall or free-standing support frame.  We’re in the process of training the plant in our Bie Havn Pollinator Garden as an espalier against the back wall.

Laurel sumac (Malosma laurina): espalier in Mother Nature's
 Bie Havn Pollinator Garden

 

In terms of practical uses, the dried fruits can be ground into flour.  The young branches can be split and used in making twined baskets.   The plant is a minor medicinal plant among the Chumash and Kumeyaay, who use a root bark tea for dysentery and baths for women’s ceremonies.

In summary, Malosma laurina is a key species of our local coastal sage scrub and chaparral plant communities.  It’s an evergreen shrub with the versatility to function as a tree, hedge or espalier.  It looks right at home with many of the plants used in S. Calilfornia native plant gardens.  And it adds to the ‘fragrance of the wild’ that makes our S. California gardens so captivating.  If you want to bring a bit of native California into your garden, this is a good shrub to consider.

Laurel sumac (Malosma laurina): Gardena Willows Wetland Preserve,
 Gardena CA

Wednesday, September 26, 2018

Plant of the Month (September) : Desert Mock Verbena – Glandularia gooddingii


Desert mock verbena (Glandularia gooddingii) - Mother Nature's Backyard


As Southern California becomes hotter and drier, local gardeners search for plants that will thrive in our changing climate. Increasingly attractive are species from the Sonoran Desert - plants that do well with heat and low rainfall.  Those that grow in washes and intermittent streams can even tolerate the occasional wet winters of western Southern California.  That’s why we’ve advocated certain Sonoran Desert plants in previous postings: http://mother-natures-backyard.blogspot.com/2015/09/sustainable-gardening-trees-for.html

Desert mock verbena is a good example of a desert plant that can transition to a garden setting. In fact, we’ve planted several in Mother Nature’s Backyard this year. While it normally blooms a bit earlier, it’s such a pretty addition we chose it as our Plant of the Month.  You may want to look for it in the fall native plant sales.

Glandularia gooddingii is native to the eastern Mojave and northern Sonoran Deserts from Southwestern Utah and New Mexico south to northern Mexico.   In California, it’s limited to the desert mountains of eastern San Bernardino County.  The common names for this plant reflect its Southwestern desert origins: Southwestern mock vervain; Southwestern vervain; Goodding's verbena; Mojave verbena.  

The scientific name honors Leslie Newton Goodding (1880-1967), a botanist and educator who collected extensively in the American Southwest, particularly in Arizona. [1]    Another well-known native plant that bears his name is the Goodding’s Black Willow (Salix gooddingii).  The scientific name is pronounced: glan-doo-LAIR-ee-uh    good-DING-ee-eye.

Desert mock verbena (Glandularia gooddingii) - growth habit

Desert mock verbena is an herbaceous perennial.  It grows only 1-2 ft. (30 to 60 cm.) tall and 2-3 ft. wide (1 meter).  The overall form of the plant is mounded to spreading.  In fact, the species is often used as a groundcover in suburban desert gardens.  The stems are slender, square and hairy.

Desert mock verbena (Glandularia gooddingii) - foliage
 

The leaves of Glandularia gooddingii are medium green and also softly hairy. Their shape is variable, ranging from lobed to coarsely toothed.  As seen in the photo, above, the leaves often have three lobes that are deeply incised or roughly toothed. The overall effect is lacy green foliage from late winter to early summer.  In the wilds, plants become dormant during the hot, dry summer.   Since our plants are young, we’ve given them a little summer water this year to get them established.  So ours remained green a bit longer.

Desert mock verbena (Glandularia gooddingii) - flower stalks
 

Gardeners like Desert mock verbena for its verbena-like flowers. If you favor the looks of verbena or lantana, this is a native to consider.  In its native setting, Glandularia gooddingii typically blooms from April to June, though it may bloom outside this window depending on summer rains or irrigation.  The flowers are lilac-purple, pale pink or white. Individual flowers are 1/2 inch (1.3 cm) wide, with five petals fused to form a tubular corolla.  Flowers grow in dense clusters on stems above the foliage.  The effect is charming and quite showy; plants will sometimes appear literally covered in blooms.  The flowers attract butterflies and hummingbirds – yet another benefit.

Desert mock verbena (Glandularia gooddingii) - flowers
 

Glandularia gooddingii can be grown in any well-drained soil.  It thrives in full sun to part-shade and needs no fertilizer unless grown in a container.   We suggest planting this species in fall or winter, then giving it winter water if nature doesn’t provide.  Plants look their best with occasional summer water – perhaps every 2-4 weeks from June to August, depending on soil and temperatures.  It’s important to let the soil dry out between waterings; plants can succumb to root rot in all but sandy soils.

Desert mock verbena is a short-lived perennial; perhaps 3-4 years is common.  But if happy, it will reseed on bare ground, keeping you in plants for years to come.  Some gardeners deadhead flowers immediately to lengthen the flowering period.  We advocate waiting to deadhead flower stalks after seeds have spread (or been eaten by birds).  That’s really about all that’s needed in terms of management.  Like most native perennials, plants will die back naturally in fall.

Desert mock verbena (Glandularia gooddingii) - first year
 

Glandularia gooddingii is one of those interesting native perennials that give native gardens their special charm.  It can be massed as a flowering groundcover or grown in a large container or rock garden as an accent. It’s a good companion plant for desert species like Baileya, Larrea, Ambrosia, and Penstemon species. [2]    The unique flowers and foliage also combine well with coastal S. California native shrubs and grasses.  We like to place it along walkways and at the front of flowering beds, where it attracts butterflies and birds.  If you’ve been toying with including some desert natives in your garden, this is a great plant to try. 

Desert mock verbena (Glandularia gooddingii) - young plant

Wednesday, August 15, 2018

Marine Blue Butterflies (Leptotes marina)



Marine Blue Butterfly (Leptotes marina)

One of the more enjoyable aspects of gardening is watching the birds and animals that visit/live in your garden.  Butterflies are among the more popular visitors, and most gardens attract a few species.  But a garden filled with nectar-rich flowers and larval host plants can be alive with many species by mid-summer.  To learn more about butterfly gardening see: http://mother-natures-backyard.blogspot.com/2012/06/butterfly-gardens.html

Among the common butterflies visiting native ‘butterfly plants’ are the small species known as the Blue Butterflies.  There are many species of ‘Blues’ throughout the world.  They all are classed as Gossamer-winged Butterflies (Family Lycaenidae), a large group that includes around 40% of all butterfly species (over 5000 species in the Family). Some of the common types of butterflies in this family are the Blue, Copper, Azure and Hairstreak butterflies.  We introduced another Gossamer-wing, the Gray Hairstreak, last month: http://mother-natures-backyard.blogspot.com/2018/07/gray-hairstreak-butterfly-strymon.html

The Gossamer-winged butterflies are mostly small.  They have delicate wings that appear to shine with color.  In the case of the Blue Butterflies, the predominant color of the upper-side of the wings is a shimmery blue that varies with the light.  Gossamer-wings live in a wide range of habitats from deserts to tropical rain forests and wetlands.  And some are common visitors to home gardens.

The Blue Butterflies belong the sub-family Polyommatinae (the Blue Butterflies).  This sub-family has traditionally been a sort of catch-all for species of similar appearance.  So it’s difficult to tell how many species it actually contains (molecular taxonomy will one day sort this out).  Southern California genera currently included in the Polyommatinae are: Brephidium (Pygmy Blues), Celastrina (Azures), Euphilotes, Glaucopsyche, Hemiargus, Leptotes, Philotes, and Plebejus. 

The most widely known (and the rarest) of the local Blue Butterflies are the Palos Verdes and El Segundo Blues (Glaucopsyche lygdamus palosverdesensis and Euphilotes battoides allyni, respectively).  These two species have very limited geographic ranges (in Western Los Angeles County) and larval food sources.  Efforts to bring these two species back from the brink of extinction have been widely publicized.  Their story has become part of the restoration ecology lore.

Mesquite (Prosopis species): larval food for
 Marine Blue Butterfly (Leptotes marina)

The Marine Blue (Leptotes marina) is a far more common butterfly in S. California.  Its range extends from California and Arizona east to Texas and south to Central  America. [1]  It’s a fairly common small butterfly in S. California, living in Mesquite and Coastal Sage scrub, city gardens and agricultural areas where alfalfa is grown. In the Sonoran Desert, it’s commonly seen along riparian corridors, which contain mesquites or other plants in the bean family.  Because its larval foods are common, gardeners in S. California, Arizona, New Mexico, southern Colorado or Texas may see this butterfly in their home gardens.  Individuals occasionally stray further north, but they apparently don’t over-winter.

The species was named by Tryon Reakirt (1844 – ?) in 1868. Reakirt was a businessman but was really a lepidopterist at heart. [2]   He joined the Entomological Society of Philadelphia at the age of 19 and became an accomplished taxonomist.  Reakirt's Blue butterfly also honors Tryon Reakirt. 

Reakirt was particularly interested in butterflies of the tropics and the American Rockies, publishing nine articles in the Proceedings of the Entomological Society of Philadelphia. He apparently was not a field collector and never visited the American Southwest. Ultimately, his business dealings failed (there were hints of corruption), and Reakirt fled to Peru in 1871.  For more on the little that’s known about this talented lepidopterist see reference 2, below.

Marine Blue Butterfly (Leptotes marina) is small

Like all the Blues, the Marine Blue is a rather small butterfly, with a wingspan ranging from 7/8 to 1 1/8 inches (2.2 - 2.9 cm). [3]  It flies with a rapid, erratic flight pattern, landing to feed or search for mates.   When perched, the wings are usually closed, making it difficult to see (or photograph) the upper wing surface.  The upper surface is an iridescent blue-purple with a hint of brown.  The males have pale brown and white markings on the upper wing surface; females are all blue-purple.  For good photos, see references 3 & 4, below.

Marine Blue Butterfly (Leptotes marina): underside

The undersurface is often the best distinguishing characteristic between the different Blues.  In the case of the Marine Blue, the underside has distinctive, wavy, tan and white bands that are reminiscent of ocean waves coming in to shore.  I’m not sure why the Marine Blue is called ‘Marine’, but suspect it’s because of the ‘waves’.  The underside also has a line of tan and white circles on the wing margins, and two larger, darker spots on the lower dorsal wing (see above).

Marine Blue Butterfly (Leptotes marina): nectaring on
Dune Buckwheat (Eriogonum parvifolium)

Adults nectar on whatever small flowers are blooming.  In our gardens, we most often see them on the native Buckwheats or plants in the Sunflower family.  They are also commonly seen around their larval food plants – the legumes (members of the Pea Family – Fagaceae).  So you may see them near the peas in your vegetable garden as well.  Common larval foods in S. California include the native Milkvetches (Astragalus species), Amorpha californica and fruticosa, Glycyrrhiza lepidota, native Lathyrus (wild pea) and Lotus species, and the non-native Wisterias, Plumbagos, Acacias, alfalfa and garden peas. In the desert, common host plants are the tree and shrubby legumes, including Mesquites (Prosopis species), Acacia greggii, Dalea purpurea and Lysiloma thornberi.

Amorpha fruticosa: larval food source for
 Marine Blue Butterfly (Leptotes marina)
 
Females lay their eggs on the flower buds of host plants. The eggs and young larvae are small and well camouflaged; you’ll have to really look for them. The larvae eat mainly the flowers and the seedpods.  For good photos of eggs, larval stages [4, 5].  For good advice on raising this butterfly see reference 5, below.

 

Marine Blues can be seen year-round in S. California and other warm places.  We see them most often in summer and fall in Mother Nature’s Backyard.  They are fun to observe and add to the interest of a garden.  But what role do they play in the garden ecosystem – and why should we be interested in attracting them?

All butterflies and their larvae provide protein for birds, wasps and other insect-eating species.  So Marine Blues certainly function as prey.  But do they also play a role as pollinators, particularly of the small-flowered species they seem to prefer? In fact, the answer has yet to be discovered.

Marine Blue Butterfly (Leptotes marina): note how hairy this species is.

Butterflies are thought to be minor pollinators for most plants.  Perhaps that’s why relatively little research has been done, except in the case of a few flowering plants.  But a good look at the smaller butterflies, like the Gossamer Wings and Skippers, makes us wonder.  These butterflies have relatively short legs (for butterflies), visit many flowers, and can be seen in large (aggregate) numbers, particularly in areas of the arid Southwest.  These butterflies are also conspicuously hairy, particularly on the underbody and around the face.  All these factors make us wonder if they are more important alternate pollinators than is often thought.

Good studies of pollinator activity are difficult to carry out.  They require time, patience, hard fieldwork and observation.  Probably the best studies document that pollen is actually carried by a pollinator.  Such studies require extreme magnification – at the level of the electron microscope.   As far as we can determine, few studies have focused on the Blues as pollinators.  We hope that some up-and-coming Southwestern lepidopterist will seize the opportunity, enlightening us on the role of the Blue butterflies as pollinators.  That would make a fantastic doctoral dissertation!

The Blue Butterflies also remind us that specialization – whether in nature, agriculture or business – carries with it a substantial risk.  The highly specialized El Segundo and Palos Verdes Blue Butterflies, with their limited larval food sources, are extremely vulnerable to habitat loss.  The more generalist Marine Blues, with their ability to utilize a range of native and non-native legumes, have lots more options.  The Marine Blue serves to remind us that flexibility can be a reasonable survival strategy in times of rapid change – like now.   

Marine Blue Butterfly (Leptotes marina):
Madrona Marsh Preserve, Torrance CA


 
See our other insect postings for more on common insect visitors to S. California gardens: http://mother-natures-backyard.blogspot.com/2016/07/insect-postings-mother-natures-backyard.html

 

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We encourage your comments below.   If you have questions about butterflies or other gardening topics you can e-mail us at :  mothernaturesbackyard10@gmail.com