Cal Hort Calochortus field trip (dudleyas, too)

On Sunday, I went on a field trip with the California Horticultural Society (Cal Hort) to the wilds east of Hollister to find calochortus in habitat. Here's a map showing our itinerary:

Our intrepid leader was Kipp McMichael, a calochortus expert who has grown many California species in his Berkeley garden. Kipp was the featured speaker at the March meeting of Cal Hort and gave an enthusiastic presentation of the calochortus of California (you can watch his talk here). 

For this field trip, there was a limit of five cars; I signed up early enough and was lucky to go. We met at a park in Hollister and set off from there. I saw parts of Northern/Central California I had never been to, ranging from grasslands full of plant life to sere landscapes that looked like they were on the Moon.

We had lunch at a picnic area in the Griswold Hills and shared the space with a group of gun enthusiasts who were shooting at targets. They were very considerate, offering us ear plugs and even inviting us to fire off a few rounds. When they were done, they collected their targets and all the spent bullet casings. This, too, is California.

Calochortus argillosus, growing on clay soil

Before I share photos of what we saw, here's a brief introduction to calochortus:

Introduction

Calochortus is a genus of flowering plants in the lily family (Liliaceae). It comprises a variety of species commonly known as mariposa lilies, globe lilies, cat's ears, fairy lanterns, and star tulips. The name “Calochortus“ is derived from the Greek words “kalos,” meaning beautiful, and “chortos,” meaning grass, referring to the attractive, grass-like appearance of these plants. 

Habitat and distribution

Calochortus species are primarily found in North America, with a concentration in the western United States, particularly in California. They also occur in parts of Canada, Mexico, and Central America. They typically inhabit open, sunny areas, often in grasslands, woodlands, and chaparral ecosystems. They are adapted to a variety of soil types, including rocky and sandy soils, and are often found in regions with a Mediterranean climate, characterized by wet winters and dry summers.

There are about 75 Calochortus species worldwide, about 60 in western North America and 15 in Central America. About a quarter of them grow on serpentine soils.

Special characteristics

Unique flowers: Calochortus flowers are known for their intricate patterns. They come in a range of colors, including white, yellow, pink, and purple. The petals often have distinctive markings, such as spots, lines, or blotches. As you can see in the photos in this post, it seems like each individual plant within a species has a unique look.

Adaptations: Many species are adapted to survive in challenging environments. Some species have bulbous roots that store nutrients and water, enabling them to withstand periods of drought. These adaptations make them well-suited to our Mediterranean climate.

Pollination: Calochortus flowers are typically pollinated by insects, including bees, beetles, and butterflies. They are attracted by the vibrant colors and unique markings of the flowers.

Ecological importance: As native wildflowers, calochortus play an important role in their ecosystems. They provide food and habitat for a variety of pollinators and other wildlife. Additionally, they contribute to the biodiversity and resilience of the plant communities in which they occur.

Cultural significance: Some species of calochortus have cultural significance to Indigenous peoples of North America, who have used the bulbs as a food source.

Calochortus argillosus

Our first stop was to see a population of Calochortus argillosus, the clay mariposa lily. As its Latin (and common) name suggests, it grows in clay soils. As was the case with most species we encountered, there was a lot of variability between plants; each flower was subtly different.

Calochortus argillosus

Calochortus argillosus

Calochortus argillosus

Calochortus argillosus

Calochortus argillosus

The next species we encountered was Calochortus venustus, commonly known as the butterfly mariposa lily – a rather silly name, seeing how mariposa is butterfly in Spanish. The species name venustus means beautiful, which is quite fitting. The flower I photographed was a busy destination for bees and beetles:

Calochortus venustus

Calochortus weren't the only cool plants we saw. Much to my (and my partner-in-crime Justin's) delight, we found Dudleya cymosa in several spots. In fact, Justin and I were so excited that one of our fellow field trip participants gave us the nickname “the dudleya twins.”

Dudleya cymosa, or canyon liveforever, has a wide range and a number of different subspecies, each with slightly different morphology. The first population we saw is most likely subspecies paniculata, the Diablo Range dudleya. Its flowers are a pale yellow to white yellow, more muted than the species. Even in flower, it sometimes wasn't easy to spot them on the rock walls, their preferred habitat:

Dudleya cymosa ssp. paniculata

Dudleya cymosa ssp. paniculata

Dudleya cymosa ssp. paniculata

Dudleya cymosa ssp. paniculata

Dudleya cymosa ssp. paniculata

Dudleya cymosa ssp. paniculata

Other plant discoveries included Penstemon heterophyllus, the foothill beardtongue, which can be found in all of the major coastal ranges in California and in the northern Sierra Nevada foothills. It's a particularly beautiful species, with masses of flowers. Interestingly, the flower buds are yellow, but they open to a purplish blue. The selection 'Margarita BOP' is a popular landscaping plant and widely available in the nursery trade.

Penstemon heterophyllus

Purple Chinese houses (Collinsia heterophylla), an annual:

Collinsia heterophylla

Goldback fern (Pentagramma triangularis), a dryland fern. I wish it were in cultivation; it would be a good fit for the succulents in my garden.

Pentagramma triangularis

And poison oak (Toxicodendron pubescens): very pretty with its fresh spring leaves, but oh so unpleasant if touched. As they say, “leaves of three, let them be.”

Toxicodendron pubescens

Next up was Calochortus luteus, the yellow mariposa lily. Like most (all?) calochortus, it grows in open grassland:

Calochortus luteus habitat

Calochortus luteus habitat

Calochortus luteus

Calochortus luteus

Calochortus luteus

Calochortus luteus

Calochortus luteus

Calochortus luteus

Dudleya cymosa again, this time with more vivid flowers so probably subspecies cymosa:

Dudleya cymosa

Dudleya cymosa, squished into a crack between two rocks

Most of the country we traveled through was open space. We did stop for a pee break at the Panoche Inn, seemingly in the middle of nowhere (in actuality about 40 miles south of Hollister in the Panoche Valley). In operation since the 1930s, it's a wonderful throwback to simpler times, with dollar bills pinned to the ceiling and shelves with paperback books and VHS tapes (!) to trade.

An unhurried hour later, we began to spot Hesperoyucca whipplei, the chaparral yucca. It's a common sight further south along Interstate 5, especially over the Grapevine (4,144 ft. Tejon Pass), but I was surprised to see it this far north. Our team leader Kipp said this is probably the most northerly population – and an indicator plant for Calochortus clavatus, the club hair mariposa lily. Unfortunately, Calochortus clavatus was already done flowering so all we saw were immature seed pods .

Hesperoyucca whipplei dotting the hillside

The next couple of hours were spent in the car, traveling east to Interstate 5 and then north to Patterson. There we exited I-5 and took Del Puerto Canyon Road, a spectacularly scenic drive. The first stop in Del Puerto Canyon was to see another population of Calochortus venustus:

Calochortus venustus, living up to its species name (“beautiful” in Latin)

Calochortus venustus

The final stop on our excursion was a hillside that had burned in August 2020 in the SCU Lightning Complex Fires, the fourth largest wildfire in recorded California history. The hills are still dotted with burned manzanitas and pine trees, but a great deal of the native vegetation has come back.

This spot is home to the most northerly population of Calochortus invenustus. It was discovered only recently because this location was virtually inaccessible before the fire. The species moniker invenustus means unlovely, unattractive, homely, or ugly in Latin – the opposite of venustus. This is a gross misnomer because Calochortus invenustus is anything but ugly. While it doesn't have the intricate markings of the other calochortus we saw, it's still an elegant flower, albeit on the small side. Here's Kipp McMichael taking a photo of a Calochortus invenustus:

Kipp taking a photo of tiny Calochortus invenustus

I fell in love with Calochortus invenustus and took a whole bunch of photos – maybe because it was so small, or maybe because it grows in what I thought was the most scenic spot we saw on our trip.

Calochortus invenustus

Calochortus invenustus with dried up leaves

Calochortus invenustus

Calochortus invenustus with an immature seed pod

Calochortus invenustus

Calochortus invenustus

Calochortus invenustus

At the same spot, we also sighted a few Calochortus venustus. Here's one for comparison:

Calochortus venustus, beautifully lit by the late-afternoon sun

One final photo, showing some of the other wildflowers in bloom at this location:

Del Puerto Canyon is an easy drive from Livermore, and I would highly recommend it if you ever find yourself in that part of the Bay Area.

By the time I got home, it was almost 10 pm. I'd left the house at 6:15 am, so it was a long day, but one I will remember for a good while.

About the California Horticultural Society

The California Horticultural Society (Cal Hort) is a nonprofit organization “dedicated to bringing together gardeners and garden professionals, through meetings and other events, to share their experiences.” Founded in 1933, the society is one of the oldest horticultural organizations in the state and serves as a valuable resource for gardeners, horticulturists, and plant enthusiasts.

Cal Hort meets on the third Monday of the month in San Francisco at the San Francisco County Fair Building in Golden Gate Park. Membership is $50 a year.

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