Palomar Mtn. Lichens
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Lichens of Palomar Mountain
San Diego County, California

W.P. Armstrong, Life Sciences Dept., Palomar College, 1 February 2001

A list of the common lichens along the trail from Doane Valley to Lower
Doane Valley and French Valley. Some lichens of the chaparral foothills
and riparian canyons on Palomar Mt. are also included in this checklist.

DISCLAIMER: Unlike vascular plants, there are very few illustrated keys to the lichens. Even with color photographs, it is practically impossible to identify some lichens to species. Consider yourself fortunate if you can get the correct genus. Some lichen species are very difficult to identify in the field and require microscopic examination (400X) of the spores. This is especially true of the crustose lichens where the size (in micrometers), color, shape and type of spore is critical to their precise identification. [Type of spore includes simple, one-septate, polarilocular, multiseptate and muriform.] In fact, some crustose lichen species may appear practically indistinguishable in the field, but actually have entirely different spore types and may even represent different genera. Another important characteristic (particularly in crustose lichens) refers to the rim surrounding the cup-shaped apothecia. The apothecia of some lichens resemble those of non-lichenized fungi, with a rim or margin of fungal hyphae (called a proper margin or exciple) that is usually the same color as the disk. Many lichens develop a second (outer) rim the same color as the thallus (called a thalline rim or exciple) that contains a layer of green algal cells. The presence of a greenish layer (visible with a hand lens) in the outer rim surrounding the apothecium is usually sufficient to determine if the rim is thalline or non-thalline. Some dark brown, areolate crustose lichens have a flask-shaped ascocarp (called a perithecium) with an apical pore. The apical pore often occurs at the tip of a pimplelike projection in the center of each areole. These pyrenocarpous crustose lichens often appear like a layer of dried, cracked mud on boulders along streams and shady canyon areas, and often include species of the genus Verrucaria. Many of the lichens on Palomar Mountain have enormous worldwide distributions and also occur in Europe (British Isles), Africa and South America. Many species produce microscopic soredia (clusters of algal cells intertwined with fungal hyphae). The granular soredia are produced in pustules on the surface of the lichen called soralia. Like dust particles, the soredia become airborne and travel to distant continents in one of nature's most remarkable dispersal scenarios. Isidia are small, pimplelike protuberances containing both algae and fungi which readily become detached and dispersed to new locations.

Note: In the chemical tests used on lichen thalli K = lye or sodium hydroxide (NaOH), C = Clorox bleach or sodium hypochlorite (NaClO) and P = para-phenylenediamine. In this checklist um refers to micrometer.

Images Of Soil, Rock & Bark Lichens:


    Low-growing lichens with the entire thallus firmly attached to the rock or other surface. Some crustose lichens are called "squamulose" because the thallus is composed of crowded, overlapping scales or squamules. In "areolate" lichens the thallus is cracked into numerous individual sections or areoles like angular sections of mud in a dry lake bed. The term "chinky" refers to cracked and fissured, as in the center of the thallus of some species

    A. Crustose Rock Lichens:

  1. Acarospora chlorophana: Lemon-yellow or chartreuse chinky, areolate thallus; often found on vertical rock surfaces; marginal lobation is a function of the dichotomous growth of entire thallus; several hundred spores per ascus.

  2. Acarospora schleicheri: Similar to above species; occurs on soil, rock & other lichens; apothecial disk dark and deeply depressed (concave); lobation function of a single areole. [Often with overlapping scalelike squamules; several hundred spores per ascus.]

  3. Acarospora fuscata: Thallus dark brown with weak marginal lobation; thallus chinky-areolate, 2-4 cm broad; apothecia immersed (innate) in the areoles, forming sunken brown disk; Acarospora bullata is a similar species found on exposed volcanic-gabbro rocks in chaparral foothills.

  4. Aspicilia cinerea: Very common gray crustose lichen appearing like gray paint on granitic boulders; thallus areolate, ea. areole with a flush or sunken black apothecium without thalline rim (the gray algae-bearing rim surrounding dark apothecial disk is the actual areole); apothecia innate, simply sunken or immersed in center of thallus section (areole); apothecium starting out as a tiny black dot, then growing in diameter until it forms a conspicuous black circular disk within each areole; thallus without marginal lobation as in Dimelaena spp.; K+ red (yellow turning red); Aspicilia caesiocinerea very similar except K- and difficult (if not impossible) to separate in the field. [Aspicilia may be gray-brown to ash-colored.]

  5. Buellia pullata: Originally identified as B. aethalea, but this species not listed for California. Black crustose lichen with areolate-granular thallus; thallus thin compared with other crustose spp. such as Lecidea and Dimelaena; apothecia minute (0.2 to 0.5 mm), raised and appearing like minute disk-shaped bumps (black and difficult to spot); margin of disk non-thalline, only the proper exciple present (inconspicuous and same color as disk); spores one-septate (2-celled), brown, 8 per ascus; paraphyses clavate-tipped; many blackened boulders throughout coastal San Diego county are coated with a thin layer of Buellia; B. stigmaea reported from Agua Tibia Wilderness. [Start of Lower Doane Nature Trail (across stream), soft black crustose layer on large boulders; with algal cells and 2-celled spores; also with unknown filaments.]

  6. Buellia semitensis: Greenish-gray crustose lichen; thallus granular-chinky (not distinctly squamulose or areolate); apothecia black & without thalline rim (with minute black proper exciple); spores less than 30 um, 2-celled, brown, 8 per ascus; paraphyses black-tipped; scattered on granodiorite and gabbro boulders with brown Lecidea atrobrunnea, gray Aspicilia cinerea, and brown Dimelaena thysanota; this granular-chinky, greenish-gray lichen superficially resembles the crustose bark lichen (Lecidella).

  7. Caloplaca sp. (possibly Caloplaca saxicola): Bright orange crustose lichen with marginal lobation (lobes typically less than 1mm); spores polarilocular (2-celled with wide septum, essentially ellipsoid-oval with circular locule at each end or pole); Caloplaca trachyphylla has slightly wider lobes up to 1.5 mm.

  8. Caloplaca sp. (possibly Caloplaca lobulata syn. C. modesta): Brick-red (orange) crustose lichen; areolate with weak (or without) marginal lobation; abundant apothecia (without soredia); other spp. of Caloplaca in southern California include C. decipiens and C. cinnabarina; they are difficult to identify; lime-yellow C. citrina occurs on walls of animal enclosures on Horn & Hoof Mesa at San Diego Zoo.

  9. Candelaria concolor: This is a lemon-yellow foliose lichen that superficially appears crustose; thallus consists of minute (branched) tufts of lobules with incised ends, sorediate on the margins; the undersurface of the thallus has rhizines, therefore it is foliose rather than crustose.

  10. Candelariella rosulans: Thallus lemon-yellow or mustard-colored like above; this is a true crustose lichen without rhizines; apothecia numerous; thallus K- without granular soredia as in Candelaria; Candelariella vitellina reported from Agua Tibia Wilderness; often mixed with other crustose spp. such as chartreuse Acarospora and orange Caloplaca.

  11. Dimelaena oreina: Yellow-green crustose lichen with distinct lobate margins (chinky-lobate); color of thallus and circular colonies superficially resembling Lecanora muralis; however, apothecial disk dark brown (black) unlike pinkish/tan disks of Lecanora muralis; spores brown and 2-celled, 8 per ascus.

  12. Dimelaena radiata: Gray, crustose lichen with marginally lobate thallus; apothecia numerous with black disk and gray thalline rim; spores brown, 2-celled, 8 per ascus.

  13. Dimelaena thysanota: Brown, chinky-lobate crustose lichen (chinky in center with lobate margin); apothecia numerous with thalline rim; hymenial disk black; spores brown, 2-celled, 8 per ascus; medulla K- (D. californica K+ red); common on boulders with Lecidea atrobrunnea; sometimes marginal lobation not evident; this species then resembles brown Aspicilia except with thalline rim.

  14. Diploschistes actinostomus: This gray, crustose rock lichen superficially resembles Aspicilia. It has large muriform spores typical of the genus Diploschistes.

  15. Lecanora muralis: Crustose, chinky-lobate, gray-green (greenish-yellow) lichen with marginal lobation; apothecia pinkish/tan-brown; color of thallus somewhat similar to Xanthoparmelia except thallus is dark around margin and at the tips of lobes; K-, C-, P-.

  16. Lecanora mellea: Crustose, chinky-lobate lichen with a shiny cinnamon-brown marginally-lobate thallus; apothecia lecanorine with brownish-orange apothecial disk; Dimelaena thysanota also has a brown thallus that is more distinctly areolate (and with lecanorine apothecia with black disks); spores small (less than 20 um), colorless, 8 per ascus (unlike the brown 2-celled spores of Dimelaena).

  17. Lecanora rupicola: Areolate, ash-colored crustose lichen (thallus superficially resembling Aspicilia only whiter, color of Lecidea tessellata); thallus K+y; apothecia clearly lecanorine (with thalline rim) not sunken in areole as in Aspicilia; apothecia numerous, literally packed together, covered with white powder (pruinose), whitish to ashy-gray including disks (disks buff-slightly darker gray); rim crenulate on older, larger apothecia; spores small, colorless, 8 per ascus; French Creek area, on boulders in pine forest; apothecia C+y with Clorox bleach. [According to Charis Bratt, this species is similar to L. subcarnea except Not K+ y r.] A striking white crustose rock lichen.

  18. Lecanora gangaleoides: Thallus ash-gray as in Lecanora rupicola and Lecidea tessellata, coarsely globular-granulate to areolate and thickened; apothecia with thalline rim, 1-2mm, disk tan to reddish-brown, convex; spores simple, colorless, small (less than 20 um), 8 per ascus; thalline margin crenulate (notched); French Creek area, on boulders in pine forest with Lecanora rupicola and map lichen (Rhizocarpon geographicum). [Identified by Charis Bratt; cf. L. campestris See Dobson p. 113]

  19. Lecidea atrobrunnea: Very common black or dark brown crustose lichen; thallus areolate to almost squamulose; areoles crowded, dark brown with whitish rim (especially when desiccated); scattered black apothecia without thalline rim (unlike Lecanora); apothecia flat or with raised convex disk.

  20. Lecidea tessellata: Gray-white crustose lichen with conspicuous black convex apothecia; apothecia angular and grouped together like pieces of pie (pizza); thallus thick and chinky in center; thallus areolate but without the sunken apothecia of Aspicilia; apothecia rounded or convex without thalline rim; spores small and colorless, 8 per ascus; paraphyses black-tipped; color of thallus similar to Lecanora hageni.

  21. Rhizocarpon disporum: Thallus consisting of numerous gray, convex (bullate) areoles (similar to warts) scattered over a black hypothallus; i.e. gray areoles separated from each other by black hypothallus without algae; black apothecia similar to Lecidea without thalline rim; asci containing two large, brown muriform spores (30 um to 50 um ); thallus bullate/areolate scattered over black hypothallus, resembling pepper grains or bumps on black background; R. bolanderi has flattened, brown, white-rimmed areoles similar to Lecidea atrobrunnea, but unlike simple spores of Lecidea it has brown muriform spores; R. bolanderi mixed with Aspicilia on rocks along trail near Silene (anther smut) site; flattened areolate thallus; black apothecia similar to Buellia (with faint, black nonthalline rim).

  22. Rhizocarpon geographicum Map Lichen: Thallus lime-green or apple-green, chinky-areolate with black hypothallus (prothallus) between areoles and around margins; black apothecia between areoles, without thalline rim; a common species in Sierra Nevada.

  23. Verrucaria sp. (a pyrenocarpous freshwater lichen): Black patches on boulders of Pauma Creek near junction with French & Doane Creeks, and at Weir; thallus cracked & areolate; perithecia inconspicuous with hand lens, possibly sunken (not conspicuous & pimplelike as in Verrucaria and Staurothele of Sierra Nevada streams; this may be V. aethiobola or V. margacea; some patches might be Buellia.

  24. Verrucaria viridula: Thallus dark brown (olive green when wet), chinky-areolate with pimplelike perithecia (at least partially embedded in thallus); thallus appears like layer of dried cracked mud on boulders of shaded canyons; small pimplelike perithecia about 0.2mm to 0.5mm in diameter; spores large (over 20 um), simple, colorless, 8 per ascus; saclike asci embedded in gelatinous mass of disintegrating paraphyses; acc. to Hasse V. nigrescens & V. viridula have "large" "apothecia?" wholly immersed in thallus with only the ostiole free; Fink shows the perithecia of V. viridula raised & pimplelike; the similar species V. aethiobola and V. margacea grow on boulders along streams and may also occur on Palomar Mountain; this species on boulders near large oak (Lower Doane Valley); areolae green when wet; V. nigrescens on rocks in the Palomar College Arboretum.

    B. Crustose Soil Lichens:

  25. Diploschistes scruposus: A grayish-white crustose soil lichen in moist DG around large boulders; numerous crowded, cup-shaped apothecia with gray thalline rim and black disks; spores large, 4 per ascus; spores brown, muriform (reticulate, divided into many sections like the squares of a Hershey's candy bar).

  26. Lecidea coarctata: Thin, scattered, ashy-gray (pulverulent), areolate to slightly squamulose thallus growing on rock and soil; scattered reddish-brown, flat to convex apothecia without thalline rim; apothecia very small; ascus clavate with 8 colorless ascospores; appears after winter/spring rains with liverworts & mosses; unlike other crustose saxicolous Lecidea (such as L. atrobrunnea & L. tessellata) this species has a thin, scattered areolate thallus that appears more delicate and fades away during the hot summer months.

  27. Psora decipiens: A common soil lichen; thallus squamulose-crustose; squamules (scale-like thallus) flat, pinkish-tan with white margin and black marginal apothecia; apothecia without thalline rim (similar to Lecidea); thallus K+ yellow, C-; common on soil in Anza-Borrego Desert after winter/spring rains; the squamules of P. crenata are recessed in center (this species may also occur on Palomar Mountain); P. nipponica reported from Agua Tibia Wilderness.

    C. Crustose Bark Lichens:

    [On Abies concolor & Quercus kelloggii]

  28. Buellia punctata reported on Quercus in the nearby Agua Tibia Wilderness area.

  29. Caloplaca cerina Thallus granular-crustose, whitish-gray (sometimes lacking); apothecial disk small (0.5 um) bright orange; spores 2-celled & polarilocular (not transversely septate); spores colorless.

  30. Candelaria concolor: This is actually a foliose lichen but it appears crustose; thallus greenish-yellow to lemon-yellow consisting of dense tufts of minute erect lobes with incised ends, sorediate on the margins; undersurface with rhizines (therefore foliose); common yellowish-green, granular lichen on bark.

  31. Lecanora varia: Small, greenish (moss-colored) crustose bark lichen; apothecia minute (less than 0.5 mm), numerous, with greenish thalline rim and pale greenish-yellow disk; thallus granular and poorly developed (falls apart easily); thallus C- and K-; spores small, simple, colorless, 8 per ascus; apparently a common crustose-granular species that is easily overlooked; from a distance this lichen appears like a greenish layer of Protococcus or moss on damp bark; the similar lichen Rinodina has black disks and brown 2-celled spores; the similar gray-green L. pacifica probably also occurs on Palomar Mountain.

  32. Lecidella elaeochroma: A small crustose bark lichen that is easily overlooked; thallus greenish-gray, granular-warty, 1-3cm broad; apothecia common, up to 1mm in diameter; disk black, raised-convex, without a thalline rim (the black proper exciple barely visible); spores small, simple, colorless, 8 per ascus.

  33. Ochrolechia oregonensis: Pale gray, warty, crustose patches on bark; apothecia conspicuous (1-3mm) with lecanorine margin (thalline rim with algae); disk pinkish-tan, flat or convex; spores colorless (gray?), 8 per ascus, large (more than 30 um); using 400X one ascus fills entire field of view; fairly common; similar in appearance to Lecanora; the early red dye "cudbear" is from Ochrolechia tartarea.

  34. Phlyctis argena: Gray, pulverulent, mealy crustose patches on bark; thallus covered with mealy soredia; apothecia often buried under soralia and difficult to see; spores large, colorless, clearly muriform, 1 per ascus; a very common bark lichen.

  35. Rinodina oregona: Small greenish-gray crustose patches on bark (easily overlooked); apothecia numerous, lecanorine (with thalline rim); disk black; spores brown, 2-celled, 8 per ascus; this crustose lichen superficially resembles Lecanora except that it has 2-celled brown spores like Buellia.

  36. Trepeliopsis flexuosa: Crustose lichen with a thin, powdery (granular), greenish thallus and scattered dark apothecia; it commonly grows on dead limbs and tree trunks in the forest. T. granulosa is very similar, but has a greenish-gray thallus with pinkish or brownish apothecia. Both species are reported from Cuyamaca State Park and probably also occur on Palomar Mt.


    Foliose lichens have a leaf-like or lobed thallus, loosely attached to the substrate by root-like rhizines or by a central stalk-like umbilicus. The thallus typically has an upper cortex (a dense layer of cells which protect the lichen). Under this cortex is a thin layer of algal cells (usually Trebouxia or Trentepohlia). Below the algal layer is the medulla (a loosely packed layer of fungal hyphae where carbohydrate reserves are stored). Many foliose lichens also have a lower cortex below the medulla. The thalli of some foliose lichens are also dotted with black pits called pycnidia, which are lined with minute, asexual conidia. These bacilliform spores (also called pycnidiospores) are strikingly similar in appearance to the male spermatia produced by certain nonlichenized fungi such as wheat rust. In some lichens (such as Cladonia) the primary thallus may be squamulose, consisting of numerous overlapping scales or squamules. The secondary thallus is actually fruticose and consists of hollow, upright stalks called podetia which bear apothecia at their tips. Some podetia resemble miniature golf tees bearing hundreds of tiny granular soredia in the apical cup and along the stalk.

    A. Foliose Rock Lichens:

  37. Physcia albinea or related species: A white foliose lichen forming rosettes with dissected lobes on shaded granitic boulders; thallus white compared to yellowish-green Xanthoparmelia; apothecia abundant, with thalline rim and dark (black) disk; in P. dubia and P. callosa apothecia are lacking, with granular soredia on lower surface and margin of lobe tips.

  38. Rhizoplaca chrysoleuca: An umbilicate foliose rock lichen with numerous pinkish (flesh-colored) apothecia; common in the Sierra Nevada on granite.

  39. Rhizoplaca melanophthalma: An umbilicate foliose rock lichen similar to above except the apothecia are dark gray and the undersurface is brown to black; common in the Sierra Nevada on granite.

  40. Xanthoparmelia cumberlandia: A very common foliose lichen on granodiorite and gabbro boulders; thallus pale yellowish-green to greenish-gray (not whitish-gray as in Physcia); Hale refers to this color as yellowish-green ("Hale yellow"); upper surface covered with abundant cup-shaped apothecia; apothecia with thalline rim and black disk; this species is virtually identical in appearance to X. lineola (acc. to Hale it can only be positively identified by a TLC (microcrystal) test for different phenolic acids in these two species); in another similar species X. taractica the thallus is more loosely attached and easier to remove.

  41. Xanthoparmelia mexicana: A very common foliose lichen on granitic and gabbroic boulders; thallus pale yellowish-green ("Hale yellow"), not white as in Physcia; upper surface with numerous pimplelike isidia; apothecia not common.

  42. Umbilicaria phaea: A very common umbilicate rock lichen (often called "rock tripe"); thallus brown with concentrically fissured apothecia (resembling the heating coils of an electric range); another common Sierra Nevada species is U. krascheninnikovii.

    B. Foliose Soil Lichens:

    Note: Species of Cladonia are technically fruticose because the secondary thallus consists of hollow, upright stalks called podetia which bear apothecia at their tips; however, the primary thallus may be squamulose, consisting of numerous overlapping scales or squamules. Because the primary thallus resembles a foliose lichen they are listed in this section.

  43. Cladonia chlorophaea: A squamulose grayish-green soil lichen on shady banks covered with mosses and liverworts; common in canyons and road cuts of chaparral foothills; podetium shaped like golf tee with a terminal cup containing granular soredia; cups and podetia covered with dense grayish-white mealy (farinose) soredia; margins of some cups jagged (laciniate), some with minute apothecia; podetia generally shorter and more stout than C. fimbriata; cups also much larger (broader) than C. fimbriata; basically the broad cups and stout podetia of C. chlorophaea look more like broad, jagged funnels compared with the tall, slender "golf tees" of C. fimbriata; C. pyxidata has podetia and cups very similar to C. chlorophaea but without soredia inside cup.

  44. Cladonia fimbriata: A squamulose greenish-gray soil lichen growing on shady banks with mosses and liverworts; podetium slender, hollow, unbranched with small apical cup; podetium shaped like slender golf tee with slender stalk and terminal cup; rim of cup with tiny (inconspicuous) apothecia; podetia covered with granular soredia; often mixed with populations of C. chlorophaea with shorter funnel-shaped podetia gradually expanded into larger (broader) cups; acc. to Hale these two spp. intergrade in California and are difficult to separate.

  45. Cladonia sp. (possibly C. macilenta or C. furicata): These species have unbranched or branched upright podetia without the apical cup (i.e. podetia not shaped like golf tees); podetia bearing numerous reddish or brownish apothecia at apex.

  46. Peltigera canina: Large, brownish-gray foliose lichen with conspicuous spikelike rhizines on underside; Upper French Creek on shady, moss-covered vertical rock (soil) wall.

    C. Foliose Bark Lichens:

    [On Abies concolor, Calocedrus decurrens & Quercus]

  47. Candelaria concolor: Thallus greenish-yellow to lemon-yellow consisting of dense tufts of minute erect lobes with incised ends, sorediate on the margins; undersurface with rhizines (hence, foliose); common yellowish-green, granular lichen on bark.

  48. Flavoparmelia caperata: Thallus greenish-yellow (Hale yellow); surface smooth-wrinkled with laminal soredia; apothecia lacking; medulla C- (Clorox negative); common on branches of chaparral shrubs.

  49. Flavopunctelia flaventior: Thallus more greenish than Flavoparmelia; white spots on surface; white soredia; medulla C+ (Clorox positive, turning reddish brown); in foothills on chaparral shrubs.

  50. Hypogymnia imshaugii: Gray (greenish-gray) foliose lichen (almost appearing to be fruticose; thallus branches inflated and hollow, covered on the outside with black dots (pycnidia); apothecia common; a very common lichen on conifer branches on Palomar Mountain and Cuyamaca Mountains.

  51. Melanelia glabra: An olive-green foliose lichen on the bark of oaks (Quercus).

  52. Melanelia sp. (M. subolivacea?): A common olive-green (greenish-brown) foliose lichen on bark of white firs along trail; thallus shape similar to Parmelia

  53. Parmelia sp. (P. saxatilis): Thallus whitish-gray; distinct cracks or pseudocyphellae on upper surface of leafy thallus, appearing as a network or honeycomb of white striations; medulla K+ red; thallus not "Hale yellow" as in Xanthoparmelia, Flavoparmelia, and Flavopunctelia.

  54. Physcia tenella (or P. adscendens): Small whitish-gray foliose colonies without apothecia; marginal lobes very narrow and ciliate (appearing like fringed with marginal rhizines); lower surface white; upper surface K+ yellow-green; no apothecia observed; P. callosa & P. clementei without ciliate margin lobes.

  55. Physcia stellaris (and possibly P. biziana): Whitish-gray foliose lichen with numerous apothecia and delicate dissected lobes; common on bark of oaks and conifers; medulla K-; in another similar species P. aipolia the medulla is K+ yellow; cortex white-spotted.

  56. Platismatia glauca: A gray (grayish-white) broadly lobed foliose lichen; thallus with broad (crinkly or undulate) erect lobes; apothecia none; soredia along the undulate margins of lobes; underside black and wrinkled toward the center, mottled and white toward margins; the genus Esslingeriana is very similar except it has apothecia; like the fruticose lichens Evernia prunastri and Ramalina menziesii, Platismatia glauca is very sensitive to air pollution and is endangered is southern California.

  57. Xanthoria polycarpa: A beautiful orange foliose lichen on dead branches of sycamores & cottonwoods (in forks of branchlets); numerous bright orange apothecia (thallus obscured by clusters of apothecia); sparse rhizines on lower surface, this characteristic rules out crustose Caloplaca and fruticose Teloschistes.

  58. Xanthoria candelaria: A bright yellow foliose lichen with ascending crenulate lobes and marginal soredia; oak woodlands near Lake Henshaw and on oaks near picnic tables, Inaja Memorial Park.


    Beautiful lichens with an intricately branched upright or pendulous thallus consisting of round or flattened branches. Unlike foliose lichens, fruticose lichens do not have a distinct lower surface bearing rootlike rhizines. The cylindrical branches may be hollow (as in Cladonia) or with a cord-like central core (as in Usnea). Cladonia is considered to be a fruticose lichen because of its cylindrical secondary thallus (podetia). Some of the intricately-branched "bushy" forms (such as Letharia) are used for trees and shrubs in model railroads. Some of California's most beautiful and characteristic lichens (such as "Spanish moss") are fruticose lichens. Unfortunately some of these species are seriously threatened due to atmospheric pollution. Some of these species are fairly common on the branches of ponderosa pines in Lower Doane Valley, near the trail junction to Weir.

  59. Bryoria fremontii (Old Man's Beard): A tufted or pendulous brown fruticose lichen (resembling horse hair hanging from the pine branchlets); very sensitive to air pollution.

  60. Evernia prunastri (oak moss): Thallus pale green to yellowish green ("Hale yellow"), similar in color to Xanthoparmelia; thallus branched, strap-shaped and dorsiventrally flattened; thallus white and grooved on underside; apothecia lacking; an endangered species in California, very sensitive to air pollution; in Europe oak moss is collected and made into a delicate perfume.

  61. Letharia vulpina (pine lichen): A common chartreuse, bushy lichen on the branches and trunks of ponderosa pines; thallus branches sorediate; apothecia very rare. In the very similar species Letharia columbiana the branches lack soredia and apothecia are typically present; both species are reported for Agua Tibia Wilderness. Mountain.

  62. Ramalina menziesii (lace lichen or California Spanish moss): A conspicuous, gray-green pendulous lichen draped from the limbs of oaks; thallus flattened (perforate and netlike or reticulate); apothecia common; in the coast ranges of central California literally covering the blue oaks and valley oaks (reminiscent of the Tillandsia "Spanish moss" of the southeastern United States; very sensitive to air pollution and becoming rare in southern California, still occurs along East Grade Road near Lake Henshaw.

  63. Ramalina farinacea (and possibly R. leptocarpha): A small, gray tufted fruticose lichen on the trunks of big-cone Douglas fir, incense cedar and California black oaks; thallus sorediate and flattened as in Evernia prunastri, but not white and grooved on underside (i.e. both flattened surfaces look the same); apothecia not seen; R. reagens and R. duriae very similar; R. leptocarpha with abundant apothecia; this is yet another lichen species that is sensitive to air pollution.

  64. Teloschistes chrysophthalmus: A striking fruticose lichen with gray, flattened thallus and bright orange apothecia fringed with slender spines; occasional on north-facing chaparral slopes such as the Hell Canyon drainage of nearby Rodriguez Mountain; scattered tufts on dead branches of scrub oak; with Candelaria concolor, Xanthoria polycarpa, Flavoparmelia caperata and Evernia prunastri; very sensitive to air pollution and a rare species in southern California.

  65. Usnea sp. (old man's beard): Thallus greenish-yellow (greenish-gray) composed of long, stringy pendulous branches; thallus branches round in cross section with a central cord; another lichen with a similar growth habit (Alectoria) lacks the central cord; Alectoria is common in the Coast Ranges of northern California and may occur on Palomar Mountain; one or both of these genera occur in the clear, fresh air of the Sierra San Pedro Martir, Baja California; Usnea species are very difficult to identify.

Note: This list of 64 lichen species is not complete. Some of the species are questionable and need to be verified by a lichenologist specializing in crustose, foliose or fruticose lichens. A detailed collection of voucher specimens from Palomar Mountain should be carefully compared with a reliable collection at a good herbarium specializing in lichens.

Palomar Mountain also has many species of non-lichenized fungi growing in the soil and on the bark of trees, including various umbrella-shaped mushrooms and toadstools (agarics and boletes), shelf and bracket fungi (polypores), puffballs and earthstars, stinkhorns, coral fungi, cup fungi and the black, gall-shaped Daldinia concentrica. Some of the soil fungi form a symbiotic (mutualistic) association with the roots of forest trees and mycotrophic wildflowers called mycorrhizae ("fungus-roots"). The fungus forms a mantle of millions of threadlike hyphal strands around the tree roots, thus greatly increasing the surface area of the roots and facilitating the absorption of water and minerals. The roots, in turn, furnish the fungus with sugars and amino acids. Mycotrophic ("fungus-nutrition") wildflowers (sometimes called saprophytes) also derive carbohydrate nutrients from this cozy, intimate, underground relationship. Mycotrophic wildflowers include the coral-root orchid (Corallorhiza maculata), pine drops (Pterospora andromedea), snow plant (Sarcodes sanguinea) and possibly the leafless wintergreen (Pyrola picta forma aphylla). There are also many species of non-lichenized unicellular and filamentous algae and cyanobacteria growing on moist soil and bark, and in ponds and streams, including species of diatoms (chrysophytes), Protococcus, Spirogyra, Oedogonium, Ulothrix, Nostoc and Anabaena. An interesting macoscopic green alga (Characeae: Nitella sp.) has been observed in small ponds on Palomar Mouintain and in Cuyamaca State Park (with Ranunculus aquatilis and Callitriche verna). The characteristic masses of black felt on the trunks of incense cedar is actually a non-lichenized cyanobacteria (also called blue-green algae). Under 400X magnification the felty mass consists of intertwined, branched filaments of prokaryotic cells, similar to Scytonema on the trunks of carob trees at Palomar College and on boulders and Mayan pyramids in Belize and Guatemala.

Fungi Native To Palomar Mountain
See The Wayne's Word Fungus Article
Cyanobacteria (Scytonema) In Guatemala
Mycotrophic Wildflowers Resembling Fungi
Photos Of Green Algae (Division Chlorophyta)


  1. Armstrong, W.P. and J.L. Platt. 1993. "The Marriage Between Algae and Fungi." Fremontia 22 (2): 3-12.

  2. Brodo, I.M., S.D. Sharnoff and S. Sharnoff. 2001. Lichens of North America. Yale University Press, New Haven & London.

  3. Egan, R.S. 1987. "A Fifth Checklist of the Lichen-Forming, Lichenicolous and Allied Fungi of the Contintental United States and Canada. The Bryologist 90 (2): 77-173.

  4. Fink, B. 1935. The Lichen Flora of the United States. University of Michigan Press, Ann Arbor.

  5. Dobson, Frank. 1979. Lichens: An Illustrated Guide. The Richmond Publishing Co. Ltd., England.

  6. Hale, Mason E., Jr. and Mariette Cole. 1968. Lichens of California. University of California Press, Berkeley.

  7. Hasse, H.E. 1913. "The Lichen Flora of Southern California." Contributions From The U.S. National Herbarium 17: 1-132.

  8. Nash, T.H. III, B.D. Ryan, C. Gries and F. Bungartz. 2002. Lichen Flora of the Greater Sonoran Desert Region. Volume I. Lichens Unlimited, Arizona State University, Tempe.

  9. Tucker, S.C. and W.P. Jordon. 1978. "A Catalog of California Lichens." The Wasmann Journal of Biology 36: 1-105.

  10. Vitt, D.H., Marsh, J.E., and R.B. Bovey. 1988. Mosses Lichens and Ferns of Northwest North America. Lone Pine Publishing, Edmonton, Alberta.

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