Plant Species of San Jacinto Mountain: Endemic Species
Fig. 1. Two SnJt endemic species and one SnJt near-endemic species growing side by side near the head of Andreas Canyon at the edge of Tahquitz Valley. Left: Tahquitz Ivesia, Ivesia callida, the only one in bloom in this pix. Middle: shaggy-haired alumroot, Heuchera hirsutissima. Right: cliff cinquefoil, Potentilla rimicola. Photo by James Dillane.
Click on the picture for a larger version.
There are 11 species which live only at San Jacinto Mountain (SnJt) and the Santa Rosa Mountains (SnRsMtns), plus a 12th species if it is accepted as a distinct species. Such species are called endemics, and are always fascinating to people since humans love rare things. If you want to see these endemic species, you can see them only here.
In addition, there are seven species where most of their population lives at SnJt and/or SnRsMtns, but which have a small number of individuals in neighboring areas, or in just one other location. These species are called near endemics.
The total number of endemic and near-endemic species is thus 18 or 19, depending on whether one species is accepted as a distinct species.
Twelve of these species are on CNPS List 1B - Plants Rare, Threatened, or Endangered in California and Elsewhere, and one more should be listed there, Keckiella rothrockii var. jacintensis, but for some reason is not; see webpage.
Table 1 lists the strictly-endemic species, and Table 2 lists the near-endemic species, in alphabetical order of their scientific name as given in the Jepson Manual second edition (JM2). The geographic range given is first the one in the JM2, expanded with notes. If we have a webpage on a given species, it is linked from the tables. The rarity codes for each species are also given, if they have ones.
See Information about the links from the Scientific Name and Common Name.
Table 1. Species Strictly Endemic to SnJt
# Fam Scientific Name Common Name SnJt
CNPS | CA | Global
Geographic Range 1 Aster Dieteria canescens var. ziegleri Ziegler's aster webpage 1B.2 S1 G5T1 SnRsMtns 2 Brass Draba saxosa Southern California rock draba 1B.3 S2 G2 SnJt, SnRsMtns 3 Rubia Galium angustifolium ssp. jacinticum San Jacinto Mtns. bedstraw webpage 1B.3 S2? G5T2? w SnJt 4 Rubia Galium californicum ssp. primum California bedstraw 1B.2 S1 G5T1 SCo, SnJt, but the SCo comes from just a single 1891 Parish voucher from "Reche Canyon" in San Bernardino County which may not be correctly located. 5 Saxif Heuchera hirsutissima shaggy-haired alumroot webpage 1B.3 S3 G3 SnJt, n SnRsMtns 6 Rosac Ivesia callida Tahquitz ivesia 1B.3 S1 G1 SnJt, with just two locations known, one near 8000 feet below Tahquitz Peak, and one two miles away at the head of Andreas Canyon. 7 Plant Keckiella rothrockii var. jacintensis San Jacinto Mts. keckiella webpage Missing!! SnJt 8 Polem Leptosiphon floribundus ssp. hallii Santa Rosa Mtns. linanthus 1B.3 S1S2 G4T1T2 SnRsMtns 9 Polem Linanthus jaegeri San Jacinto prickly phlox 1B.2 S2 G2 SnJt 10 Polyg Sidotheca emarginata white-margined oxytheca 1B.3 S3 G3 SnJt, SnRsMtns 11 Lamia Trichostema austromontanum ssp. compactum Hidden Lake bluecurls 1B.1 S1 G3G4T1 SnJt, with just a single known location at Hidden Lake.
Layia ziegleri, if this is accepted as a species, is a strict endemic. However, it is not accepted as a species in the JM2. Layia ziegleri was defined by Munz in 1969 in the Supplement to A California Flora, with type from grassy-meadowy slope between Mountain Center and Keen Camp Summit, at 4750 feet. He wrote:This proposed species seems nearest to Layia glandulosa ssp. lutea and to L. pentachaeta. It resembles the former in its basal dentate leaves, entire cauline leaves, stipitate-glandular peduncles and involucres, ring of bracts between ray and disk fls, yellow anthers, setaceous pappus, etc., but differs in the more numerous subterete pappus-bristles which are scarcely plumose and not wholly at the base. From L. pentachaeta it differs in its involucre not being pustulate-hirsute and the less plumose pappus. From both taxa it is well removed geographically.
In the JM2, this species was synonymized with Layia platyglossa.
Table 2. Species Nearly Endemic to SnJt
# Fam Scientific Name Common Name SnJt
CNPS | CA | Global
Geographic Range 12 Erica Arctostaphylos parryana ssp. desertica desert Parry manzanita PR (SnJt, SnRsMtns, San Ysidro Mtns). The vast majority of the population is at SnJt and SnRsMtns. 13 Brass Boechera johnstonii Johnston's rock cress webpage 1B.2 S1 G1 B. johnstonii is endemic to SnJt if Arabis hirshbergiae is not merged with it. If they are merged, as done in the JM2, it is a near endemic, with the only other location near Cuyamaca Lake 14 Lilia Calochortus palmeri var. munzii Munz's mariposa lily webpage 1B.2 S3 G3T3 SnJt in JM2 (which includes SnRsMtns), but there are now a small number of vouchers from south of SnJt 15 Celas Euonymus occidentalis var. parishii Parish's burning bush PR in JM2, but only two locations outside SnJt and SnRsMtns: Palomar Mtn State Park and Cuyamaca Rancho State Park 16 Aster Hulsea vestita ssp. callicarpha beautiful hulsea 4.2 S3 G5T3 near endemic to SnJt, SnRsMtns; other locations Palomar; Hot Springs Mtn; Cuyamaca Peak 17 Plant Penstemon clevelandii var. connatus San Jacinto beardtongue 4.3 S3 G5T4 e slope SnJt, SnRsMtns, but vouchers extend down the PR 18 Rosac Potentilla rimicola cliff cinquefoil 2B.3 S1 G2 SnJt, northern Baja. It appears to have only one other location, in the Sierra San Pedro Martir in Baja CA. There are only 3 vouchers of it from Mexico at SEINet.
Penstemon californicus is found only at SnJt in California, but it is found in the PR in nearly the entire length of the northern part of Baja Californica.
If two neighboring codes are given for a taxon, such as T1T2, it indicates there is uncertainty as to whether it should be ranked T1 or ranked T2.
- CNPS Rare Plant Ranks
- 1B: Plants Rare, Threatened, or Endangered in California and Elsewhere
- 2B: Plants Rare, Threatened, or Endangered in California, But More Common Elsewhere
- 4: Plants of Limited Distribution - A Watch List
- CNPS Threat Ranks (numeric code after the rare plant rank, as in 1B.2)
- 0.1 - Seriously threatened in California (over 80% of occurrences threatened / high degree and immediacy of threat)
- 0.2 - Moderately threatened in California (20-80% occurrences threatened / moderate degree and immediacy of threat)
- 0.3 - Not very threatened in California (less than 20% of occurrences threatened / low degree and immediacy of threat or no current threats known)
- CA = California State Rank
- S1 - Critically Imperiled — Critically imperiled in the state because of extreme rarity (often 5 or fewer occurrences) or because of some factor(s) such as very steep declines making it especially vulnerable to extirpation from the state.
- S2 - Imperiled — Imperiled in the state because of rarity due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors making it very vulnerable to extirpation from the nation or state.
- S3 - Vulnerable — Vulnerable in the state due to a restricted range, relatively few populations (often 80 or fewer), recent and widespread declines, or other factors making it vulnerable to extirpation.
- Global Rank (Gx gives the species rank; Tx gives the subspecies / variety rank)
- G1/T1 - Critically Imperiled — At very high risk of extinction due to extreme rarity (often 5 or fewer populations), very steep declines, or other factors.
- G2/T2 - Imperiled — At high risk of extinction due to very restricted range, very few populations (often 20 or fewer), steep declines, or other factors.
- G3/T3 - Vulnerable — At moderate risk of extinction or elimination due to a restricted range, relatively few populations (often 80 or fewer), recent and widespread declines, or other factors.
- G4/T4 - Apparently Secure — Uncommon but not rare; some cause for long-term concern due to declines or other factors.
- G5/T5 - Secure — Common; widespread and abundant.
Citation for CNPS Rare Plant Ranks: CNPS, Rare Plant Program. 2016. Inventory of Rare and Endangered Plants (online edition, v8-02). California Native Plant Society, Sacramento, CA. Website http://www.rareplants.cnps.org [accessed 19 September 2016].
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Updated 29 October 2017.