Mt. Wilson, Sunday, July 15, 2007

 Species List 
 Combined Stats for Macrolichens 

I walked from Chantry Flats to Mt. Wilson via the Upper Winter Creek Trail and Toll Road, then returned via the Rim Trail and Devore/Sturtevant.  All told it was maybe 18 miles, and about 2500' elevation change, from Sturtevant at about 3500' to Mt. Wilson a few hundred shy of 6000'.  The entire trail up was on the ocean-side, mostly E and N slopes, ending on S slopes.  The Rim Trail is nearly entirely in the lea of the E-W ridge.  I collected almost nothing on the trail down from Newcomb Pass. 

The species list below should represent a fair collection of all but the rarest foliose, fruticose, and squamulose lichens along the trail: perhaps as much as 75% of the macrolichen species within a few feet of the trail, but I doubt even as much as half the species present on the mountain as a whole.  However, it should only be considered a cursory sampling of the commonest or most interesting crustose species, especially the saxicolous species, as I relied entirely upon collecting specimens on fragments that flaked off of the rocks naturally.

Where possible I stepped off the trail to collect, however it is clear that the dust from the trail has significantly enriched the lichen communities on the base of trunks immediately adjacent the trail, both above and below.  So I was not always able to find equivalent specimens off the trail.

Vouchered specimens are kept for each of the species listed.  In almost all cases the specimens are fragments, just enough to provide confident identification.  At some later date each taxon will be linked into my notes, but for now that functionality doesn't exist on the website.

Species List 

I found 35 macrolichen species:

Candelaria concolor bark, occ wood/rock 3000-6000' abundant
Cladonia hammeri moss/rock 3000-5000' common
Cladonia subradiata moss/rock 3000-4000'  
Dermatocarpon americanum granite 5000-6000'  
Flavopunctelia flaventior moss/rock 3000-4000'  
Hypocenomyce scalaris pseudotsuga bark 4000-6000' abundant
Hypocenomyce sierrae moss 5000-6000'  
Leptochidium albociliatum moss/rock 4000-5000'  
Letharia columbiana conifer bark/wood 5000-6000'  
Letharia vulpina pseudotsuga bark, occ wood 4000-6000' common
Melanelia glabra oak bark, occ granite 4000-5000' frequent
Parmelia saxatilis granite 4000-5000'  
Parmelia sulcata granite 4000-5000'  
Parmelina quercina oak bark, occ granite 4000-5000' frequent
Physcia adscendens granite 4000-5000'  
Physcia biziana granite, occ wood 4000-6000' frequent
Physcia caesia granite 5000-6000'  
Physcia tenellula oak bark and granite 4000-6000' frequent
Physcia tribacia granite 5000-6000'  
Physciella chloantha oak bark 3000-5000'  
Physconia americana oak bark 4000-5000' frequent
Physconia californica oak bark 4000-5000' frequent
Physconia enteroxantha oak bark 4000-6000'  
Physconia isidiigera oak bark and granite 3000-6000' common
Physconia perisidiosa oak bark 4000-6000' frequent
Platismatia glauca pseudotsuga bark 4000-5000'  
Rhizoplaca melanophthalma granite 5000-6000' frequent
Umbilicaria phaea granite 4000-6000' common
Xanthomendoza fallax oak bark 5000-6000'  
Xanthomendoza fulva oak bark 5000-6000'  
Xanthoparmelia californica granite 3000-4000'  
Xanthoparmelia coloradoensis granite 4000-5000'  
Xanthoparmelia lineola granite 3000-4000'  
Xanthoparmelia mexicana granite 3000-4000'  
Xanthoparmelia subdecipiens granite 5000-6000'  

I found 15 crustose species:

Buellia sp.?  oak bark 3000-4000'  
Caloplaca igneacement 5000-6000'  
Candelariella vitellina granite 5000-6000'  
Chrysothrix candelarisoak bark, occ granite 3000-6000' common
Lecanora cenisia granite 5000-6000'  
Lecanora hagenii oak bark 5000-6000'  
Lecanora mellea granite 4000-5000'  
Lecanora muralis muralis granite 4000-6000' common
Lecidea mannii granite 5000-6000'  
Lepraria lobificansgranite, occ oak bark 3000-6000' common
Lepraria diffusa moss 5000-6000'  
Ochrolechia subpallescens oak bark 4000-6000' common
Rhizocarpon disporumgranite 5000-6000'  
Rhizocarpon geographicum granite 5000-6000' common
Rinodina herrei oak bark 4000-5000'  

Combined Stats for Macrolichens 

Here I compare this partial flora on Mt.  Wilson with the partial flora given me by Kerry Knudson for San Jacinto Wilderness.  It's perhaps not a particularly instructive comparison, as the latter is significantly higher in elevation, but I was interested in it, nonetheless, because I wanted to back up quantitatively the subjective observation I made a few weeks ago that the macrolichen community was rather poor on San Jacinto.

  species genera
Mt. Wilson 35 18
San Jacinto 26 15
overlap 8 11
total 53 22

And here is a breakdown of number of genera/species by distance from trailhead, and by elevation.

  species genera
within 3 mi 10 7
within 6 mi 23 14
total 35 18

  species genera
3000-4000' 9 6
4000-5000' 21 14
5000-6000' 18 10
total 35 18

Note: The elevation profile above is misleading because the majority of the trail I followed was between 4000-5000', and I stopped collecting specimens I already had on the way down, so 3000-4000' and 5000-6000' are both underrepresented compared to 4000-5000'.

The relative dearth of species close to the trailhead, however, is obvious to the casual observer.  Past 4 or 5 miles (approximately above 4500', or about halfway up to the Toll Road) the richness of the macrolichen community starts to plateau.  The bases of most oaks next to the trail have a majority coverage beyond this point, and the oaks on the Rim Trail do not show significantly greater coverage. Letharia, however, continued to increase noticeably in abundance all the way to the top of the mountain. [NOTE]

The following three tables show number of species of each genus present on Mt. Wilson and San Jacinto, respectively. 

Genera present in both:

 Mt. WilsonSan Jacinto
Dermatocarpon 1 1
Hypocenomyce 2 1
Letharia 2 1
Melanelia 1 3
Parmelia 2 1
Physcia 5 2
Physconia 5 2
Rhizoplaca 1 1
Umbilicaria 1 3
Xanthomendoza 2 3
Xanthoparmelia 5 3

Genera present only on Mt. Wilson:

 Mt. WilsonSan Jacinto
Candelaria 1 0
Cladonia 2 0
Flavopunctelia 1 0
Leptochidium 1 0
Parmelina 1 0
Physciella 1 0
Platismatia 1 0

Genera present only on San Jacinto:

 Mt. WilsonSan Jacinto
Nodobryoria 0 1
Phaeophyscia 0 2
Psora 0 1
Xanthoria 0 1

Copyright ©2007 Jason Hollinger
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Last changed on August 2, 2007