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

Table of Contents

Introduction and Photographs of These 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

Introduction and Photographs of These Species

We have five Calochortus species at San Jacinto Mountain, 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 are Calphotos.

Table 1. The Five Calochortus species at San Jacinto Mountain

Scientific NameCommon Name# of VouchersElevation Range (feet)Haploid # (n)
C. concolorgolden-bowl mariposa452000-51007
C. invenustusplain mariposa lily, green-stripe mariposa lily265300-95007
C. palmeri var. munziiMunz's mariposa464100-55007
C. plummeraePlummer's mariposa lily202000-47009
C. splendenssplendid mariposa lily201500-45007, 14

There are vouchers of C. splendens at 4900 and 5500 feet, but we are suspicious that those vouchers are not correctly determined.

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.

Fig. 1 shows photographs of our five species. The first row shows a face-on view of the flower; the second row shows a side-view.

C. concolorC. invenustusC. palmeri var. munziiC. plummeraeC. splendens
Fig. 1. The five Calochortus species at San Jacinto Mountain. Top row: frontal view of flower. Bottom row: side view of flower. Click on the pictures for larger versions.

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

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

Calochortus species are often hard to separate. 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

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 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. 2, and for just the west side of SnJt Mountain in Fig. 3. Maps of accepted vouchers for each species individually are linked here:

Fig. 2. Geographic distribution of vouchers of the five Calochortus species at SnJt. (See also map with roads labeled)

Fig. 3. Geographic distribution of vouchers of the five Calochortus species on the west side of SnJt.

Elevation Distribution of These Species

Fig. 4. Plot of the elevation vs. longitude for vouchers of the five Calochortus species at SnJt.

Fig. 5. 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.

Only C. invenustus is found at elevations above 5500 feet; accepted voucher map.

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 appears to be 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 side of SnJt. There are three vouchers from 5000 to 5500 feet in the Idyllwild Area: 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. Accepted voucher map.

C. concolor is found nearly everywhere at SnJt below 5100 feet; accepted voucher map.

C. plummerae appears to be the least common species (at least from vouchers) at SnJt, being found primariliy west of Idyllwild below 4000 feet. One voucher, 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. 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. 6 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. 6. 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 26 May 2020.