Walnuts, anyone?

July 9, 2015

by Carol Bornstein

Photo by Carol Bornstein

Squirrels and humans have something in common – both love nuts. If you skip the added salt and oil, these tasty “fruits” are good for you, too. And if you are interested in foraging – with permission and proper identification, of course - several of California’s native trees and shrubs offer up some mighty flavorful nuts. Just ask the squirrels!

For centuries, Native American tribes throughout California have harvested native hazelnuts, pine nuts, and walnuts. Birds, squirrels, and other wildlife also feast upon these nutritious foods. Here in the Los Angeles Basin, southern California black walnuts (Juglans californica) are still relatively easy to find in the Santa Monica Mountains, growing among coast live oak, toyon, elderberry, sycamore, and other woodland or chaparral vegetation. This deciduous tree is an important food source for Western gray squirrels (Sciurus griseus) and ground squirrels, and many kinds of birds use cavities in older trees as nesting sites. It is ironic that wild populations of this native tree, so widely used as rootstock for commercial walnut orchards, are threatened by urbanization. Recognizing this, the city of Los Angeles added southern California black walnut to its short list of protected tree species in 2006. 

If you visit the museum’s Nature Gardens, you can see a thriving young tree just east of the bird-viewing platform (see map above for location, indicated by the yellow arrow). We planted it two years ago from a 15-gallon container and since then it has tripled in size (although at one point we almost lost it thanks to Eastern fox squirrels (Sciurus niger) chewing on the tender trunk).

Imagine my surprise when I noticed a crop of young walnuts on our tree this past spring. Six round, bright green nuts were beginning to ripen among the leafy branches. What fun! A couple weeks later, only three were left. Suspecting that the squirrels were helping themselves, we tied protective cloth bags around the remaining nuts so that visitors would have a chance to see mature walnuts on the tree. Well, somehow a squirrel managed to get two more nuts, further evidence that the Nature Gardens are indeed habitat for wildlife!

Even if the solo remaining walnut disappears, we are confident that the tree will produce another, bigger crop next year. It would be fun to use the husks for dye and to share the oil-rich nutmeats with some lucky visitors.



(Posted by: Emily Hartop)

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California Holly: How Hollywood Didn't Get its Name

December 18, 2013

In Nancy Dale’s 1986 epic tome of Southern California native plants, Flowering Plants, she has this to say about Toyon — aka California Holly, Christmas Berry, or, if you’re a botanist, Heteromeles arbutifolia:

“It is thought that masses of this native shrub growing on the hills above Hollywood gave the community its name.”

This idea of floral origins for Hollywood is romantic. It’s also not true. Hollywood got its name for a much more mundane reason: someone wealthy liked the sound of it.

Toyon on Los Vaqueros Watershed Miwok Trail, photo by Miguel Vieira

In 1886, Harvey Henderson Wilcox, a rich prohibitionist from Kansas, and his wife, Daeida, purchased 120 acres of apricot and fig groves near the Cahuenga Pass at $150 an acre. Harvey, an inveterate businessman, realized he could make a lot of money by subdividing the land and selling the lots for $1,000 a pop. And so the Wilcox subdivision, as Hollywood was then known, was born.

A year later, on a train journey back to Ohio, Daeida Wilcox befriended a fellow wealthy traveler who just happened to own a fine estate in Illinois. Its name was Hollywood. The story goes that Daeida was so taken with the name that upon her return to California she encouraged Harvey to apply the name to their property. On February 1, 1887, the name was immortalized when Harvey filed a subdivision map to the Los Angeles County recorder's office, with the name “Hollywood.”

The Wilcox map of Hollywood-courtesy of the USC Libraries, California Historical Society Collection

But long before Daeida’s chance encounter and the installation of an enormous “Hollywoodland” sign, Toyon — or California Holly — was growing in the Hollywood Hills. These shrubs and the brilliant red berries that adorn them have been growing in Southern California for hundreds, if not thousands, of years. We’re not quite sure how far back they go: Scientists at the Natural History Museum, where I work, haven't found any in the La Brea Tar Pits yet, so it seems they’ve been here less than 10,000 years.

Toyon and Hollywoodland sign, 1937-courtesy of the Los Angeles Public Library photo collection

Before the Europeans showed up, the indigenous peoples of the area used Toyon for food, medicine, and tools. Making use of a plant isn’t unusual, but this plant’s name is. According to California Native Plants for the Garden (co-authored by the Natural History Museum's director of the nature gardens, Carol Bornstein), "Toyon is the only California native plant that continues to be commonly known by a Native American name." Toyon was the name given by the Ohlone people, and it stuck.

Two years ago, we planted about 25 Toyon in the Natural History Museum’s new Nature Gardens. Toyon are a mid-sized shrub in the rose family and can grow up to 20 feet; ours are now standing tall at a stately 10 feet. We knew they would fill in the garden pretty quickly, and provide great cover for many birds, mammals, and insects we wanted to attract.

In early summer their showy white flowers are magnets for native pollinators, which help to produce the bright red fruits that catch our attention at this time of year. If you cut open a berry—more technically known as a pome—the inside looks a lot like the core of an apple, and birds love them. Last year a large flock of Cedar Waxwings, Bombycilla cedrorum, descended on our mini Toyon grove. One of our gardeners noted that it only took these birds a matter of two weeks to clear out every last morsel.

Thankfully, there’s plenty of Toyon to go around as the shrub ranges all the way south into Baja California and north into the Sierra Nevada.

To Angelenos of the early 1900s, Toyon was better known as California Holly. The shrub closely resembles another winter evergreen, European Holly, Ilex aquifolium. Both have green leathery leaves with spiky edges and bright red berries that fruit in winter, and consequently were used to adorn people's homes as yuletide decorations. Lore has it that over-harvesting of the berries in the early 1900s led to a California state law outlawing the gathering Toyon on public lands. I couldn't find any evidence for this, but the story is repeated in many places, including on Wikipedia's Toyon entry.

Is California Holly our state’s most apocryphal plant? Perhaps. In 2012, it also earned the distinction of being named L.A.’s official native plant by the City Council. But we remain lucky that it ultimately wasn’t a neighborhood namesake. Can you imagine a huge sign over our city that reads TOYONWOOD? No, neither can I.











(Posted by: Lila Higgins)

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Bird's Nest Fungi, Exploding Eggs, and Mushroom Soup

July 12, 2012

Yay! Today I documented the first bird's nest fungus, Cyathus sp., in the North Campus. For months, I have been looking forward to finding these fascinating, weird, and wonderful fungi. When North Campus Director Carol Bornstein told me she had found some, I immediately knew I had to blog about them.

Bird's Nest Fungi with my finger for scale.As you can see, this fungus looks like a miniature bird's nest with oddly flattened eggs in it. Mycologists refer to them fondly as BNFs, bird's nest fungi. The "eggs" (periodoles to be geeky and precise) are actually packages containing thousands and thousands of spores. When a raindrop, or some other drop of water, hits the periodole it causes a miniature explosion. The spores are released and propelled out of the cup (some spores can be projected over six feet in this manner), and attach to a suitable substrate by means of a special sticky base.  How'd they get here? Very likely, they hitched a ride in with a potted plant, or on the mulch we spread to suppress weeds and help keep the soil moist.

Look at those lovely periodoles!BNF and their closely related kin puffballs, earthstars, and stinkhorns all belong to the group of fungi that produce their spores inside of the fruitbody. In contrast, the white button or portobello mushroom, Agaricus bisporus, that you would buy at the grocery store, produces spores on the fruitbody. Next time you are the grocery store, pick up one of these mushrooms and look underneath the cap. If the cap has opened, you will see hundreds of gills. Each of these gills is a place for hundreds of spore producing structures. Unlike BNF, these mushrooms do not need rain for their spores to spread. Instead, when the spores are ripe, they are shot into the small space between gills. Gravity then takes hold and the spore falls down towards the earth. As the spore comes into contact with the air, it is gently carried away, hopefully in the direction of a suitable susbtrate it can attach to and continue the cycle. Woah, I can't wait to contemplate the spore's amazing journey over my next bowl of mushroom soup!

(Posted by: Lila Higgins)



First Baby Oaks Sprout Up in the North Campus

February 2, 2012

The North Campus is the proud parent of some baby oak trees!

Baby coast live oak sheltered by wallCarol Bornstein, our new Director of the North Campus Gardens, discovered a couple of oak saplings on one of her recent outdoor forays. The babies are coast live oaks, Quercus agrifolia, of which we recently planted several trees. We've also planted another species of oak, the Engelmann oak, Quercus engelmanni (we planted only three of this species). Both species reside in the section of the garden called the urban wilderness which is composed of several kinds of California native trees and shrubs.

This might be the mother oak!Oak trees provide amazing habitat value, and this is the main reason we planted them. By putting in such a  sizable stand of oaks we're hoping our created wilderness will provide habitat for a whole slough of organisms rarely, if ever, seen before in Exposition Park. In just one oak tree it would be easy to find hundreds of species of associated plants and animals and thousands of individuals (think how many birds, ants, or squirrels you find in an oak tree). One species that has already shown up with our oaks, is a tiny insect called a whitefly.

Crown whitefly nymphs on oak leaf(each nymph is only 1 millimeter long)It was once again thanks to Carol, who was out inspecting our lovely oaks, that we discovered these small insects. At first we thought they might be a scale insect, but Brian Brown, the Museum's Curator of Entomology, identified them as crown whiteflies, Aleuroplatus coronata. As adults these small white homopterous insects (group of insects consisting of aphids, cicadas, scales, etc) fly around to find a suitable location to lay their eggs. For the crown whiteflies their plant of choice is oak. What you see in the image above are the nymphs (immature forms) of the whitefly, they have no wings but are covered with white waxy secretions that make them look like little crowns. The nymphs feed on the leaf's juices by piercing and inserting their mouthparts into the leaf. They can cause damage to the plant's health if their numbers are high enough, and they can also transmit disease organisms from one tree to another (not unlike mosquitos transmit malaria).Go check out your local oaks and see what animals live on them!

(Posted by: Lila Higgins)