Plant Species of San Jacinto Mountain: Calochortus species, Mariposa Lilies

Table of Contents

Introduction and Photographs of the San Jacinto Mountain Calochortus Species
How To Identify These Species
Geographic Distribution of These Species
Elevation Distribution of These Species
Discussion on the Geographic and Elevation Distribution of These Species
Evolutionary Relationship of These Species

C. concolor
golden-bowl mariposa lily
C. invenustus
green-stripe mariposa
plain mariposa lily
C. palmeri var. munzii
Munz's mariposa lily
C. plummerae
Plummer's mariposa lily
C. splendens
splendid mariposa lily
Fig. 1. The five Calochortus species at San Jacinto Mountain. Top row: side views of flowers. Bottom row: frontal views of flowers.
Pix by Bruce Watts and Tom Chester.
Click on the pictures for larger versions.

Introduction and Photographs of the San Jacinto Mountain Calochortus Species

Everyone loves the flowers of Calochortus, Mariposa Lilies, since they are big and showy, and almost unbelievably variable in appearance, even within a single species. The (Spanish) common name is from the resemblance of the flower to a butterfly. Calochortus flowers are more cooperative than butterflies, since they don't fly away when you approach them to admire them. (:-) The scientific name of Calochortus is from the Greek word kallos for "beautiful" and chortus, "grass," referring to the grassy leaves.

We have five Calochortus species at San Jacinto Mountain (abbreviated as "SnJt" at times below), given in Table 1 and shown in Fig. 1. The scientific name in Table 1 is linked to the online Jepson Manual eflora, and the common name is linked to pictures at Calphotos.

Table 1. The Five Calochortus species at San Jacinto Mountain

Scientific NameCommon NameTypical
Bloom time
# of
# of
iNat obs
Elevation Range
# (n)
C. concolorgolden-bowl mariposaJune4544*2000-52007
C. invenustusplain mariposa lily, green-stripe mariposa lilyJune, July26115 5300-95007
C. palmeri var. munziiMunz's mariposaJune4648*4000-53007
C. plummeraePlummer's mariposa lilyMay, June, July206*2000-48509
C. splendens
(C. davidsonianus)
splendid mariposa lilyMay, June201500-39007, 14

* The numbers for these species are somewhat uncertain since the locations at iNat are obscured, throwing some observations into the San Jacinto Mountain area and throwing some observations out of it.

The number of iNat observations is probably skewed higher for C. invenustus since it blooms in the high country when there are many hikers present. Likewise, the number of iNat observations is definitely skewed low for C. plummerae, since its largest population, in the Chimney Flats area, blooms in July, when there are few hikers present due to the heat and lack of shade there.

Our southern California plants called C. splendens are actually C. davidsonianus. Floras have lumped C. davidsonianus in with C. splendens, but it appears to be morphologically and genetically distinct; see C. davidsonianus and C. splendens. However, to avoid confusion, we'll use the name C. splendens in this page.

The elevation ranges in Table 1 have been modified from those solely from vouchers to accurately reflect what we have seen at San Jacinto Mountain. Notes on the elevation ranges given in Table 1:

Interestingly, Calochortus flowers are not popular with butterflies, probably because they can't easily access the nectaries.

However, some bees love the flowers just as much as we humans do, and use the flowers as a "single's bar", a place to hang out and meet insects of the opposite sex. Aaron Schusteff reports that the male fairy bee (Perdita sp.) hangs out in the flower, waiting for the female, and then they mate in the flower. (Btw, the linked pictures showing the bees were taken by Tom solely for the flowers; the bees were noted later by Aaron!)

The female is a pollinator for the flowers, gathering all the pollen she can get from each flower, presumably for her eggs. Aaron watched a female try to get every single pollen grain from a C. concolor flower on Chalk Hill on 16 June 2014!

The flowers open fully in the morning, between 8 and 9 a.m. PDT, and partially close in the afternoon between 4 and 5 p.m. (Those times might be variable, depending on weather conditions.) Linda St. John, who grows a number of Calochortus species, reports that they do not completely close overnight.

Linda also reports that an individual flower in cultivation lasts from three to six days. Blooms may not last that long in drought years in the field. Bruce Watts observed one flower of C. invenustus that apparently only lasted a day. Tom Chester analyzed photos of 24 flowers in Tahquitz Meadow in a small area at the same time, and found they could be sorted into four categories which imply a flower lasts four days.

The flowers may be functionally male for the first two days, with the stigma being receptive to pollen only on the third day (as observed for C. leichtlinii, which is similar to C. invenustus, in Holtsford 1985). This appears to be true for C. invenustus as well; see Tom's analysis.

Linda reports that near the end of the bloom of an individual flower, the seed pod is beginning to develop as the petals curl vertically and eventually fall off. The seed pod takes a long time to mature -- a month or more until it begins to open at the top to release the seeds.

All our Calochortus species have a haploid number of 7 except for C. plummerae, with a haploid number of 9. Species with different haploid number cannot produce hybrids. Interestingly, C. concolor evolved from ancestors with a haploid number of 8; see Evolutionary Relationship of These Species.

Figs. 1 and 2 show photographs of our five species. Fig. 1 shows both a side-view and a frontal view of a typical flower. Fig. 2 shows some of the variation seen at SnJt. See Color Variants for more information on some of these variants.

Pictures of the fruit variation are shown in Fig. 2b.

C. concolorC. invenustusC. palmeri var. munziiC. plummeraeC. splendens
(intentionally blank)
(intentionally blank) (intentionally blank)
Fig. 2. Some of the variation seen at San Jacinto Mountain in the flowers of our five Calochortus species.
Pix mostly by Bruce Watts, with a few by Tom Chester.
Click on the pictures for larger versions.

Color Variants

C. concolor. The normal flower color is a "rich yellow" with at least some red near the base of the petals, but it can have pale yellow to orange flowers (Gerritsen and Parsons 2007 p. 146), and the amount of red at the base of the petals varies a lot. The flowers shown in Fig. 2 are arranged from yellow at the top to orange at the bottom. Note that just above the orange flower at the bottom is a dark yellow flower with orange veins.

We have only observed pure orange flowers once at San Jacinto Mountain, from a small number of immediately-post-fire plants near the Spitler Peak Trailhead; see Fig. 1. We saw the plants only a single year, 2014, following the 2013 Mountain Fire, and saw no trace of them (such as leaves) in subsequent years, which seems very odd.

C. palmeri. Bruce Watts has censused the C. palmeri population at San Jacinto Mountain, counting over 46,000 plants in bloom. Out of all those flowers, he found only four flowers that were entirely white except for the yellow hairs near the nectary. Bruce said that some other flowers appear to be white, but closer examination shows they are a very faded pink color.

Additional photographs of our species, showing more of the variation in appearance for two of our species, are linked below:

Pictures of Fruit

C. concolorC. invenustus
C. palmeri var. munziiC. plummerae
Fig. 2b. Fruit of four of our five Calochortus species at San Jacinto Mountain. The variation in the fruit of C. invenustus is real. The leftmost one, that is near the color of C. concolor fruit, is from Tahquitz Meadow, on the same plant that has a flower of C. invenustus.
Pix by Bruce Watts and Tom Chester.
Click on the pictures for larger versions.

How To Identify These Species

Although the four lavender species are sometimes confused, these species can be easily distinguished as follows:

Geographic Distribution of These Species

An accurate geographic distribution relies on accurate determinations of individual plants. Alas, Calochortus species are often hard to separate when one has a fresh specimen, and much more difficult to separate when dried and pressed, when the green stripe of C. invenustus fades away and all the flowers turn yellowish. In particular, specimens of C. invenustus, C. palmeri and C. splendens all have been misdetermined in the past as another one of this set of three species, both in vouchers and by us, before we learned the reliable separation characteristics given above.

In the following maps, we have discarded four vouchers as being probable misdeterminations, and have made comments on them online suggesting that the vouchers be reexamined for the determination; see Table 2.

Table 2. Vouchers discarded as being misdetermined

Voucher NameDetermination of VoucherProbable Correct Determination
RSA773589Calochortus invenustusCalochortus palmeri var. munzii
JEPS61650Calochortus invenustusCalochortus palmeri var. munzii
RSA68632Calochortus splendensCalochortus invenustus
RSA285891Calochortus splendensCalochortus palmeri var. munzii

There are three vouchers from 5000 to 5500 feet in the Idyllwild Area which are almost certainly misdetermined if their locations are correct: from 5500 feet in Woods above James Reserve (RSA633887, 1969); 5400 feet from M. fk. San Jacinto River. On west bank of pond at Desert Sun School near Idyllwild (RSA784190, 1959); and 5000 feet from "Idlewild" (RSA377463, 1949). Those vouchers and locations should be checked to see if C. splendens really lives in those areas, which is extremely doubtful.

One voucher of C. plummerae, RSA701502, is at 4650 feet in an area dominated by C. palmeri. That voucher and location should be checked as well to verify that C. plummerae really lives there.

One voucher, RSA291571, had erroneous coordinates, being placed south of the Lake Hemet Campground instead of the Thomas Mountain Campground. We supplied better coordinates with an online comment.

We discarded all vouchers with vague localities since they cannot be georeferenced accurately.

Previously, on 22 November 2010, Tom had examined a voucher of "C. kennedyi" from Garner Valley, RSA377389, that was actually an unusual very short yellow-flowered C. concolor, that LeRoy Gross redetermined as C. concolor, which was the determination of a dupe of that voucher, RSA377346.

We also discarded a voucher of "C. excavatus" from Jepson himself in 1903, JEPS17807. C. excavatus is extremely close to C. invenustus, differing only in the color of the anthers. The other three differences given in the Jepson Manual first edition (bract length; bracts opposite vs. alternate; purple spot or not on the petals) are not true differences.

The geographic distribution of the accepted vouchers is shown for all species in one plot, for all of SnJt Mountain in Fig. 3, and for just the west side of SnJt Mountain in Fig. 4. Maps of accepted vouchers for each species individually are linked here:

Fig. 3. Geographic distribution of vouchers of the five Calochortus species at SnJt. (See also map with roads labeled)

Fig. 4. Geographic distribution of vouchers of the five Calochortus species on the west side of SnJt.

Elevation Distribution of our Calochortus Species

The elevation distribution of our Calochortus species is given in Figs. 5 and 6.

Fig. 5. Plot of the elevation vs. longitude for vouchers of the five Calochortus species at SnJt.

Fig. 6. Plot of the elevation vs. longitude for vouchers of the five Calochortus species on the west side of SnJt.

Discussion on the Geographic and Elevation Distribution of These Species

In the following, each species has a link to a voucher map for its distribution made from the vouchers accepted here.

With only a very few exceptions, noted here and below, our Calochortus species do not grow together, although the edges of their ranges can be very close. The biggest exception is that Walt Fidler found C. concolor, C. plummerae and C. splendens growing together on a hill along SR243 at 3740 feet elevation.

Only C. invenustus is found at elevations above 5500 feet; accepted voucher map. No other Calochortus species grows with it.

C. palmeri has a fairly tight distribution, found above 4000 feet ranging from just west of Idyllwild and Mountain Center to Vandeventer Flat at the lip of the desert escarpment along SR74; accepted voucher map.

C. splendens is mostly a lower-elevation species, being extremely common in the coastal area to the west of SnJt, and found up to about 4000 feet on the west and north side of SnJt. Accepted voucher map.

C. concolor is found nearly everywhere at SnJt below 5100 feet; accepted voucher map. It intermingles with C. palmeri only in a small part of the Kenworthy area, and a small part of the Quinn Flat area.

C. plummerae is the least common species at SnJt, being found primarily west of Idyllwild below 4850 feet. The eastern part of its range in the Chimney Flats / Old Control Road area touches the western part of the range of C. palmeri, but the species are separated on habitat there. C. plummerae grows on dry, rocky, south-facing slopes in full sun or partial shade from shrubs, whereas C. palmeri grows in grassy meadows and can grow in quite shady area such as north-facing slopes. Accepted voucher map.

Evolutionary Relationship of These Species

Patterson and Givnesh 2003 reported a wonderful genetic analysis of Calochortus that elucidated the evolution and relation of 67 Calochortus species, including five varieties or subspecies. See their complete paper for all of their fascinating results. The following extracts a small amount of information from that paper for four of our five species (C. invenustus is not mentioned in their paper, possibly because its DNA could not be aligned unambiguously).

Patterson and Givnesh state that Calochortus species evolved in the Coast Ranges of California 3-5 million years ago, with the estimated date of the intial divergence of Calochortus species from each other being 7.3 ±0.9 million years ago. They place the species in seven evolutionarily-related clades that are mostly, but not entirely, geographically coherent.

Fig. 7 shows a subset of their strict consensus cpDNA phylogeny of Calochortus, with the names of four of our species repeated to make it easier to see where they are found in the figure.

Fig. 7. A subset of the strict consensus cpDNA phylogeny of Calochortus from Patterson and Givnesh 2003. The colored lines indicate the sections and subsections of the genus delineated by Ownbey 1940; black lines indicate where a color cannot be assigned since there are mixed subsections found more recently in the tree.

In the following, the base chromosome number is delineated by the usual x symbol, with the haploid chromosome number for each species delineated by the usual n symbol. See ploidy for an explanation of these numbers.

Two of our species are closely related, C. davidsonianus / splendens and C. palmeri, placed in the Southwestern California group with C. flexuosus and C. dunnii. This group has x=n=7, except for one tetraploid population of C. davidsonianus with n=14.

C. concolor is in the Great Basin - Rocky Mountains group, even though its distribution is California and Baja California, not the Great Basin. C. kennedyi is a close relative of C. concolor, and we have been struck by the similarity in stature of the C. concolor plants at SnJt to C. kennedyi plants. In addition, both species come in yellow and orange/red colors, with C. concolor being mostly yellow and C. kennedyi being mostly orange. This group has x=8, with only C. concolor and C. leichtlinii both switching to x=n=7.

C. plummerae is in the San Diego group, with C. weedii a close relative, apparent just from looking at all the hairs inside the flower. The chromosome number is x=n=9 for this group.

C. invenustus was not mentioned in Patterson and Givnesh 2003, but Ownbey placed it in same group with C. concolor. If molecular data eventually supports that, it would be another species that switched from x=8 to x=7.

Voucher data provided by the participants of the Consortium of California Herbaria on 26 May 2014.

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Updated 10 July 2022.