Plant Species of the San Jacinto Mountains
Chrysolepis sempervirens, chinquapin
Fig. 1. A huge stand of chinquapin on the east-facing slope above Wellman Divide on dry, rocky soil that can only support a few conifers. The view is to the northwest. See Fig. 3 for the location of this stand. Click on the picture for a larger version..
Fig. 2. A distant view of another huge stand of chinquapin on the east-facing slope on the southeast side of Jean Peak north of Wellman Divide. The view is to the west. The trail to San Jacinto Peak goes through this huge stand. See Fig. 3 for the location of this stand.
Fig. 3. A Google Earth view to the west of the big fields of chinquapin, outlined in white, on the east-facing slope below the ridgeline from Marion Mountain on the left, to Jean Peak in the middle, to San Jacinto Peak on the right. Filled pink circles give the locations of GPS'd chinquapin. The hiking trail from Wellman Divide to the switchback just below Miller Peak is clearly delineated by the large number of GPS'd locations of chinquapin along it. Both Jean Peak and San Jacinto Peak have chinquapin at their summits. Note the very sparse distribution of chinquapin in the lower parts of Round, Tamarack and Long Valleys.
This page currently exists only to hold the pix shown in Figs. 1 to 3, and the geographic and elevational distribution maps shown in Figs. 4 to 6.
Some of the things to be added in the future:
- mention that this is in the oak family, with an acorn fruit, and show it.
- meaning of name
- mention its occurrence as individual plants, but more often as dense thickets. what is the cause of the dense thickets?
- difficulty in establishing.
- fire survival by resprouting. examples from Tahquitz Peak.
- male / female plants, together and sometimes separately.
- typical slope exposures of eastern-facing or north-facing here. But at higher latitudes, it grows mostly on south-facing slopes!
- growth in dryish areas that can't support trees.
- bird predation on the acorns - our observations
- galls that grow on the stamens!
- estimate number of plants at SnJt.
For more information on this species, see Howard 1992: Chrysolepis sempervirens In: Fire Effects Information System: .
Distribution in San Jacinto Mountain
The geographic distribution of chinquapin at San Jacinto Mountain is shown in Fig. 4, from 287 locations from our observations and 114 locations with good locations from iNat observations. A zoomed-in view of the distribution in the high elevation area and Round / Long / Tamarack Valleys shown in Fig. 5.
Fig. 4. Geographic distribution of chinquapin at San Jacinto Mountain.
Fig. 5. Geographic distribution of chinquapin at the highest elevations of San Jacinto Mountain, as well as in Round, Long and Tamarack Valleys. Note the very sparse distribution of chinquapin in the lower parts of Round, Tamarack and Long Valleys, where we have done many point surveys that did not find chinquapin. Don Rideout and Tom Chester surveyed from the Tram to Miller Saddle along the Round Valley Low Trail recording the locations of chinquapin along that entire route. None were found in most areas along the Round Valley Low Trail. In contrast, a large number of locations were recorded from just below Wellman Divide to Miller Saddle.
Fig. 6 shows a histogram of the elevations for observations with good locations, from our observations and iNat observations. Note the three interesting peaks, at elevations of 7800 to 8000 feet; 8400 to 8800 feet; and at 9600 to 10040 feet. Those elevations correspond to the mostly-east-facing slopes below the Marion Mountain / Tahquitz Peak ridge; the ridgelines on the eastern edge of Long Valley and on the northern side of Long Valley; and on the east-facing slopes below the Marion Mountain / Jean Peak / San Jacinto Peak ridge. If we had been able to record the locations of those huge patches of chinquapin shown in Fig. 3, the peak in the histogram at 9600 to 10,040 feet would be much larger.
Fig. 6. Histogram of elevations for chinquapin observations with good locations.
We thank Don Rideout for help with GPS'ing chinquapin from the Tram Station to Miller Saddle on 6 August 2021.
Copyright © 2021 by Tom Chester and Dave Stith.
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Comments and feedback: Tom Chester
Updated 10 August 2021.