Common names such as butterfly mariposa, splendid mariposa, superb mariposa, and Diogenes’ lantern tip us off that the genus Calochortus is a thrill. And once again, the East Bay (Alameda and Contra Costa counties) has more than its fair share of that thrill. Here is a quick skip through the genus with the focus on East Bay species.
First, some photos of dreamy Calochortus flowers:
And some figures: California is graced with almost 50 species of Calochortus, all of which are native, and 10 of which are endemic (i.e., occur only within California). Within the CNPS East Bay Chapter area (Alameda and Contra Costa counties), we have:
- 10 species
- Seven that are rare
- One that is presumed to be endemic
A little fun here (answers are at the end of this article):
1. Approximately how many Calochortus species are there worldwide?
2. What percentage of worldwide Calochortus taxa occur on or are restricted to serpentine soils?
3. How long ago did Calochortus diverge from its closest relatives?
Now, some facts: Calochortus is a genus in the lily family, Liliaceae. The current scientific thinking is that this genus arose right here in California, in the Coast Ranges. The four flower forms (floral syndromes to scientists) that humans perceive are:
- mariposa – flowers upright with vertical petals, like a tulip; name is Spanish for butterfly
- fairy lantern – flowers dangle like lanterns hanging from hooks; also called globe lily
- star tulip – upright flowers with petals that lie nearly flat, forming a star shape
- cat’s ear – with triangular, fuzzy, nearly horizontal petals
DNA sequence data show, however, that floral syndromes often vary among close relatives in Calochortus. For example, the five fairy lantern species in Central Mexico are more closely related to mariposa species of that area than to the five fairy lantern species of the Coast Ranges and Sierra Nevada in California. Another conclusion from genetic studies is that the ancestral floral syndrome for this genus is the mariposa; so far, so good in terms of the world being straightforward, but other results are just wild. For example, the cat’s ear floral syndrome evolved independently at least three times over in three geographic areas! But back to the world making sense again, it is reported that mariposa floral syndrome species are adapted to open, dry habitats; cat’s ears to woodlands; star tulips to generally open sites; and fairy lanterns to habitats under tree canopies.
Here are the species in the East Bay, organized by flower form, and labelled “rare” if they are included in our CNPS East Bay Chapter’s Database of Rare, Unusual and Significant Plants of Alameda and Contra Costa Counties or the CNPS Inventory of Rare and Endangered Plants of California.
Mariposa flowers
- C. argillosus, clay mariposa
- C. clavatus var. pallidus, clubhair or pale yellow mariposa, rare
- C. invenustus, plain mariposa, rare
- C. luteus, yellow mariposa, rare
- C. splendens, splendid mariposa, rare
- C. superbus, superb mariposa
- C. venustus, butterfly mariposa, rare
Fairy lantern flowers
- C. albus, white fairy lantern
- C. pulchellus, Mount Diablo fairy lantern; rare
This is the presumed East Bay endemic. There are a few observations of C. pulchellus from widely scattered locations in Solano County, but the well-accepted specimens are all from Contra Costa County.
Star tulip flowers
- C. umbellatus, Oakland star tulip, rare
A few more facts: Calochortus is a geophyte genus. Geophytes grow from underground storage organs (in Calochortus, those storage organs are bulbs), which allow aboveground parts to die back under harsh conditions. Refresh your memory on geophytes in the gorgeous Fremontia issue dedicated to this growth form. Native American tribes in California and elsewhere traditionally harvested and consumed the bulbs of certain Calochortus species. Calochortus bulbs send shoots up annually, and some Calochortus species bloom profusely after fire.
Horticulturally, the Fremontia issue referenced above states the obvious: Calochortus in a garden is spectacular. It also recommends the fairy-lantern forms as some of the easiest to grow. Our chapter’s Native Here Nursery sells Calochortus bulbs, as do a few other local native plant nurseries. This genus is a good garden addition for attracting and supporting native pollinating insects too.
And now, the fun: a contest!
With the hope that we can safely get out into wild nature next spring, we invite you to join our 2021 Calochortus Contest. Who can find all ten species of East Bay Calochortus, and who can find them first? Prizes include gift certificates valid at Native Here Nursery and other fun gifts for native plant lovers. If you are interested in helping to coordinate the contest, contact Sally de Becker (vice-president@ebcnps.org).
In the meantime, you can learn about southwestern Calochortus species, including some from the Bay Area, in an online lecture offered by the Santa Barbara Botanic Garden: Not All Butterflies Fly: Mariposa Lilies of Southwest California presented by Fred Roberts, June 27, 4:30 – 6 pm (registration required; sliding scale fee starting at $15).
Answers (to questions above):
- Calochortus species worldwide number about 75, all of which are in western North America (about 60 species) or Central America, primarily in Central Mexico (about 15 species).
- One quarter of all Calochortus taxa occur on or are restricted to serpentine soils.
- Calochortus diverged from its closest relatives approximately 40 million years ago.
We hope this introduction to Calochortus inspires you to learn more. Check out the references below, and be sure to look for these beautiful flowers in the wild next spring.
— Sally de Becker
Vice President, CNPS East Bay Chapter
June 2020
The author gratefully acknowledges the thorough technical review of this article by Dr. Thomas Givnish, Henry Allan Gleason Professor of Botany and Environmental Studies, University of Wisconsin–Madison.
Sources of information for this article and links to additional fascinating material:
Special Issue: California Geophytes, Fremontia 44:3, December 2016.
Calochortus Lilies Catch the Eye, Lech Naumovich, Bay Nature 15:2, April-June 2015.
Mariposa Lily, Los Padres Forest Watch.
Calochortus, Pacific Bulb Society.
Calochortus: Mariposa Lilies and Their Relatives, Mary E. Gerritsen and Ron Parsons, Workman Publishing, 2007.
Geographic cohesion, chromosomal evolution, parallel adaptive radiations, and consequent floral adaptations in Calochortus (Calochortaceae): evidence from a cpDNA phylogeny. Thomas B. Patterson, Thomas J. Givnish. New Phytologist 161: 253-264, 2004.
Calochortus Native to California, Calscape: Restore Nature One Garden at a Time.
Calochortus, Jepson eFlora: Vascular Plants of California
Calflora: information on wild California plants
