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The Bryologist 95(3), 1992, pp. 329-333 Copyright © 1992 by the American Bryological and Lichenological Society, Inc.

Texosporium sancti-jacobi, a Rare Western North American

BRUCE MCCUNE Department of Botany and Pathology, State University, Corvallis, OR 97331-2902

ROGER ROSENTRETER Bureau of Land Management, State Office, 3380 Americana Terrace, Boise, ID 83706

Abstract. The lichen Texosporium sancti-jacobi (Ascomycetes: ) is known from only four general locations worldwide, all in western U.S.A. Typical habitat of Texosporium has the following characteristics: arid or semiarid climate; nearly flat ground; noncalcareous, nonsaline, fine- or coarse-textured soils developed on noncalcareous parent materials; little evidence of recent disturbance; sparse vegetation; and dominance by native plant species. Within these constraints Texosporium occurs on restricted microsites: partly decomposed small mammal dung or organic matter infused with soil. The major threat to long-term survival of Texosporium is loss of habitat by extensive destruction of the soil crust by overgrazing, invasion of weedy annual grasses and resulting increases in fire frequency, and conversion of rangelands to agriculture and suburban developments. Habitat protection efforts are important to perpetuate this species.

The lichen Texosporium sancti-jacobi (Tuck.) revisited. The early collections from that area have vague Nadv. is globally ranked (conservation status G2) location data while more recent collections (1950s-1960s) by the Rare Lichen Project (S. K. were from areas that are now heavily developed and pre- sumably do not support the species. New sites were sought Pittam 1990, pers. comm.). A rating of G2 means in likely areas, especially in southwest Idaho, northern that globally the species is very rare, and that the , and eastern Oregon. At each site where Texos- United States Rare Lichen Project maintains a file porium was found we recorded approximate population on the species, notifies local governmental jurisdic- size, substrates, site characteristics, and signs of recent disturbance such as fire, grazing, and rodent burrowing. tions of occurrences, and, as warranted, seeks listing Additional unreported collections of Texosporium were on the U.S. Fish and Wildlife Service Threatened sought from ASU, CANL, COLO, ID, NY, ORE, OSC, SBM, SFSU, and Endangered List. The species is also an Idaho SRP, uc, us; the private herbaria of Ann DeBolt, Roger BLM Sensitive Species and Idaho Native Plant So- Rosentreter, and Bruce Ryan; and the herbarium (u ps) of the most recent monographer of the order Caliciales (Ti- ciety Priority 1 Species (Idaho Native Plant Society bell 1984). 1991; Moseley Groves 1990). Nomenclature of vascular follows Hitchcock and Texosporium is monotypic. It is known histori- Cronquist (1973), while that of follows Egan (1987). cally from near San Diego, (Nadvornik 1942; Tuckerman 1883), and more recently from RESULTS AND DISCUSSION Pinnacles National Monument, California (Smith Texosporium sancti-jacobi 1990), near Boise, Idaho (Rosentreter 1986), and Descriptions of are in north of Bend, Oregon (A. DeBolt, unpubl.). It is Weber (1967) and Tibell and Hofsten (1968). Brief- Texosporium part of the biotic crust that covers much of the soil ly, forms an inconspicuous whitish to surface in many semiarid and arid sites. Very little grayish crust on soil and organic matter. Its apo- has been known about its habitat requirements and thecia are quite distinctive and easier to spot in the the influences of management practices on this spe- field than the thallus. The apothecia are typically cies. circular, 0.5-1.5 mm diameter, whitish-margined, The objectives of this study were to gather infor- and with a dark-blackish, powdery center that is mation on site characteristics, disturbance history, tinged with bright yellow from the secondary prod- and vegetation at the known locations for Texos- uct calycin. The apothecia tend to occur in clusters porium, and attempt to locate additional popula- that are seldom more than 1 cm in diameter. tions by field and herbarium searches. The known distribution (Fig. 1) is very spotty, ranging from the historic sites near San Diego north to central Oregon and southwest Idaho. Site char- METHODS acteristics are summarized in the list of locations We visited sites where Texosporium had previously been below. Further details of locations, collecting his- found; however, historic sites near San Diego were not tory, and ecological data are in McCune (1992). 0007-2745/92/329-333$0.65/0 330 THE BRYOLOGIST [VOL. 95

LOCATIONS tional associated species in Idaho were Trapeliopsis The following list includes all known sites for sp. and others reported by Rosentreter (1986) The Texosporium, excluding the historical collections Chalone Creek, California population had very few with vague collection data, i.e., "San Diego." Her- soil crust associates, mainly the dark K+ red Cal- ifornia relative ofAspicilia reptans baria of the authors are indicated by MCC and RR. and several small Riccia. "BLM" refers to the United States Department of species of The ridgetop population at Pin- Interior, Bureau of Land Management. nacles in California was also associated with the California relative of Aspicilia reptans, but con- U.S.A. CALIFORNIA. SAN BENITO CO.: Pinnacles Nat. Mon., tained numerous additional species not found in the Chalone Creek, 293 m, Desjardin 1274 (SFSU, UPS), McCune Chalone Creek community: Cladonia squamules, 19114 (Mcc, us); Chalone Creek at Bear Valley, Pinnacles Nat. Mon., 290 m, Desjardin 2055 (sFsu); High Peaks Leptogium sinuatum, Xanthoparmelia coloradoen- ridge, Pinnacles Nat. Mon., 790 m, McCune 19139 (Mcc, sis, and several bryophytes. Pinnacles National Monument herbarium, us). SAN DIEGO The vascular vegetation likewise had many com- CO.: Delmar, N of Torrey Pines State Park, Weber Mc- monalities among the northern sites but little in Coy 36684 (cow); Kearney Mesa, Weber Santesson common between the northern and the California 43119 (cow); Camp Kearney, Parks L117 (COLO). I DAHO. ADA CO.: 4 km SW of Owyhee, Rosentreter 1239 (cow, sites. All of the northern sites were dominated by RR), Rosentreter 1665 (cow, mcc, RR), Rosentreter 3081 some species of Artemisia, including A. tridentata (ASU, CANL, COLO, MCC, RR, SFSU, SRP); 4 km ESE of Owy- subsp. wyomingensis (most commonly) and subsp. hee, 885 m, DeBolt Doremus, not collected; Pleasant tridentata and A. arbuscula, often with Chrysotham- Valley Road, 882 m, Rosentreter 6815 (RR); Tenmile Ridge, nus nauseosus, 900 in, DeBolt 1521 (Boise District BLM herbarium). ELM- a seral species. All northern sites had ORE CO.: 1-84 Simco Road, 1,000 m, Rosentreter 6819b Poa sandbergii and other bunchgrasses, especially (RR). OREGON. JEFFERSON CO.: Big Canyon, 730 m, Mc- Agropyron spicatum, Sitanion hystrix, and Stipa Cune, not collected; The Island, 730 m, DeBolt Rosen- species. The Oregon locations also had widely scat- treter 6514 (Prineville District BLM herbarium, RR), tered Juniperus. The sites at Pinnacles had widely McCune 18973 (Mcc, us). scattered Adenostoma fasciculatum but otherwise had little in common with each other or the Oregon HABITAT and Idaho sites. The Chalone Creek site was largely Texosporium was always found in arid to semi- bare, with a few sprigs of Festuca octoflora and Bro- arid grasslands, shrublands, or savannas, at eleva- mus rubens, bordered by Adenostoma and Eriogo- tions up to 1,000 m. Parent materials in all areas num fasciculatum. On the ridge at Pinnacles, Tex- were noncalcareous, including basalt, granite, and osporium was intimately associated with a large mat mixed alluvium. The soils developed on these par- of Selaginella, surrounded by widely scattered Ad- ent materials varied greatly, from very fine-textured enostoma and Pinus sabiniana. soils on basalt (the Oregon sites and some Idaho sites), to sandy foams (Simco Road, Idaho), to soils DISTURBANCE HISTORY high in fine or coarse sand (Pinnacles National Mon- ument). Soil texture appears to be less important The sites with Texosporium had few signs of re- than soil chemistry, as no Texosporium was found cent disturbance, although all had been grazed by on the numerous calcareous and saline sites ex- wild animals. Most of the sites from which T. sancti- amined. jacobi is known have had little or no grazing by Soil depth at Texosporium sites also varied great- domestic animals in recent years. The fair to poor ly, from thin soils over bedrock (Oregon sites and range condition at two of the Idaho locations sug- Pinnacles ridge site), to moderately thick soils re- gests a past history of intensive grazing or fire fol- stricted by a caliche layer (Snake River Plain sites), lowed by a prolonged period (> 20 years) without and deep alluvial soils (Pinnacles stream terrace). severe disturbance (Rosentreter 1986). This sug- gests that Texosporium populations can recolonize areas following severe disturbance, although the ASSOCIATED VEGETATION process is slow. The apparent recolonizing ability The associated soil crusts differed between the suggests that Texosporium would respond favorably California sites and the more northern sites. In Ida- to improved management practices and habitat pro- ho and Oregon the soil crust is typically well de- tection efforts. veloped where Texosporium is found. Associated Examination of a recently burned site formerly lichens in both Oregon and Idaho included Acaros- occupied by Texosporium and adjacent to an exist- pora schleicheri, Aspicilia reptans, Buellia punctata, ing Texosporium site showed that the population Candelariella terrigena, Cladonia pocillum, Colle- had been completely eliminated by the fire. When ma sp., Diploschistes muscorum, Lecanora muralis, burned sites become dominated by Bromus tecto- Phaeorrhiza sareptana, and Psora species. Addi- rum, the predominant pattern in recent years, it is 1992] McCUNE ROSENTRETER: TEXOSPORIUM SANCTI-JACOBI 331 not clear whether Texosporium and other soil crust species can reestablish. TEXOSPORIUM • Extant in 1991 Historical sites CAUSES OF RARITY AND MEANS OF SURVIVAL Texosporium has an unusual type of rarity (Ra- binowitz et al. 1986), having wide (but disjunct) geographic distribution, restricted habitat, and a lo- cal population size that everywhere is small. Al- though it has a wide range in North America (1,300 km north to south), it is rare both regionally (Fig. 1) and locally. That is, populations are difficult to find, and when they are found, the colonies tend to be few, small, and dispersed. Several factors may act to produce the regional rarity of Texosporium. It appears to be intolerant of calcareous, saline, and heavily disturbed sites. Numerous calcareous and saline sites with well-de- veloped soil crusts were examined in Idaho and Nevada, but no Texosporium was found on those sites. Grazing tends to disrupt the soil crust and promote conversion from bunchgrasses to weedy annual alien grasses (especially Bromus species and RU Elymus caput-medusae) which promote frequent FIGURE 1. Known world distribution of Texosporium burning (Whisenant 1990). Texosporium and the sancti-jacobi. Solid circles indicate populations confirmed biotic soil crust in general are essentially absent from in the last few years. The star near San Diego indicates these semiarid sites dominated by annual grasses. historical populations that have probably been extirpated. The widespread conversion of sagebrush—bunch- Small empty circles are major cities. The map was devel- oped from a Goode basemap, copyright University of Chi- grass communities to alien annual grasslands has cago Press. been promoted by overgrazing and fire (Whisenant 1990; Yensen 1982). Texosporium is always rare locally. Even in sites posed to the point that they crumbled with gentle where it is known to occur, it may take a trained finger pressure. Some of them had begun to lose observer an hour to locate a colony. This local rarity their original form in situ. It seems likely that where is probably the result of a very restricted range of small bunchgrasses such as Poa sandbergii are ab- suitable microhabitats. There is always an organic sent, Texosporium occurs primarily on small-mam- component to its substrate, although the particular mal dung. class of acceptable substrates is seldom abundant. Several life history characters favor its long-term Two particular substrates are most commonly col- persistence, despite its rarity and habitat restric- onized by Texosporium: dead bunchgrass stubble tions. The unusual spore characteristics of this spe- that is thoroughly impregnated with soil, and old cies may provide critically important reproductive partly decomposed small-mammal dung, especially traits. We hypothesize that the spores have an un- that of jackrabbits (Lepus) and rabbits (Sylvilagus). usually high desiccation resistance and longevity, It was not observed growing on old dung of domestic and that these characteristics are provided by the animals or wild ungulates. In Idaho and Oregon, combination of large spore size and the thick hyphal Texosporium was most often found on the typically coating of the spores. The fungal coat may provide 2-10 cm diameter lumps formed by dead Poa sand- some measure of protection against desiccation. This bergii. These are often somewhat pedestalled and protection would not only allow longer spore via- typically are fragile and susceptible to destruction bility in place, but should also improve survival by grazing animals. On the same lumps other soil during long-distance dispersal. crust species are common, especially Diploschistes The spore mass is densely infused with calycin. muscorum and Buellia punctata. Presumably this substance increases the likelihood The colonies found in Pinnacles National Mon- of maturation and longevity of the spores by pro- ument in California were always on partly decom- viding some antibiotic activity (e.g., see Lawrey posed small-mammal dung. Texosporium was also 1989). seen occasionally on those substrates in Oregon and The spore coat is very dark at maturity. This may Idaho. Typically the pellets of dung were decom- provide some protection against the high levels of 332 THE BRYOLOGIST (VOL. 95 radiation in exposed, sunny habitats. This feature 1982). Large areas have been converted to agricul- may promote spore longevity by protecting the nu- tural uses. The remaining area has mostly been cleic acids from damaging radiation. transformed by fire and Bromus tectorum into an exotic-annual grassland with a high fire frequency (Whisenant 1990) and almost no biotic soil crust, STATUS SUMMARY or overgrazed to the point of destruction of the bi- Although records of T. sancti-jacobi have in- otic crust. Thus, ensuring the long-term persistence creased in recent years, this reflects an increase in of Texosporium in southwestern Idaho will require scrutiny of possible sites by lichenologists rather some habitat protection efforts (e.g., see Pellant than any real increase in population size. To the 1990). contrary, relatively intact steppe and savanna eco- Texosporium is known from only two popula- systems, of the kind from which Texosporium is tions in Oregon, both on the dissected basalt pla- known, have been reduced to isolated remnants (de- teaus near the confluence of Crooked River, Des- tailed further below). chutes River, and the Metolius River in central Texosporium is uncommon at all sites where it is Oregon. The two populations are about 6 km apart. known. Where it occurs it constitutes much less than One site ("The Island") is in an Area of Critical 1% of the biotic crust. Most of the sites from which Environmental Concern managed by the Bureau of Texosporium is known have had little or no grazing Land Management and has historically been pro- by domestic animals in recent years (perhaps 10 or tected from domestic grazing by topography making more years). Its occurrence in fragile microsites that it inaccessible to domestic animals. It is a nearly are readily destroyed by grazing and other soil dis- flat remnant of dissected basalt plateau surrounded turbance suggests that its future is in jeopardy. How- by cliffs. The other site, on the rim of Big Canyon ever, it occurs at several sites in Idaho that were northwest of The Island is apparently used on oc- historically heavily grazed or burned but have had casion for hunting camps. Texosporium is absent little or no grazing or fire in recent years (Rosentreter from the immediate vicinity of the camps, probably 1986). This suggests that Texosporium can respond due to disturbance by horses. The population is best favorably to habitat protection and restoration ef- developed in very rocky, thin-soil areas near the forts, at least in those areas where remnant popu- rim that probably have had less horse and cattle use lations exist (such as southwest Idaho). in the past and have probably burned less often The earliest known populations of T. sancti-ja- because of sparse fuels. These natural protections cobi were from near San Diego, especially in the will probably continue to foster Texosporium in this Kearney Mesa area. Because of suburban devel- area. opment in this area, most or all of those populations may have been destroyed. However, this area was not visited in the course of this study. Attempts IS THIS SPECIES IMPORTANT? should be made to locate remnant populations in Is Texosporium a significant resource, such that the San Diego area. efforts and expense should be expended to ensure The populations in Pinnacles National Monu- its survival as a species? Although the species has ment appear healthy and are likely to persist under no direct economic value at present, it does have Monument protection. The overgrazing and soil considerable scientific importance. disturbance observed outside the Monument have Texosporium is important to science in part be- been so thorough that populations are probably few cause it is the only known species of its . Fur- and far between. No Texosporium was found in thermore, its habitat and growth form are unusual grazed areas examined outside the Monument. for the Caliciales. But the most distinctive feature More populations of Texosporium are known in of this species is its spores, which are quite different southwestern Idaho than from any other area. This from those of virtually all other spore-producing may be due partly to favorable habitat and partly organisms. As the spores of Texosporium develop, to the extensive observations in that area by Ro- the ascus bursts, then the surrounding hyphae in the sentreter and A. DeBolt. Despite the relatively large mazedium reorganize to form a thick tight covering number of populations known for this area, the pop- over each spore (Tibell Hofsten 1968). ulations are clustered in only three sites. Texospori- Functionally, the fungal spore coat may be similar um is threatened by the ongoing loss of good-con- to the protective coverings found in seed plants. dition Artemisia tridentata subsp. wyomingensis This lichen has evolved a structure apparently anal- rangelands on the Snake River Plain. Although Ar- ogous to the seed coat or dry fruits of many flowering temisia steppe was historically the dominant veg- plants. As such, it appears to provide an extreme etation on the valley floor, most of this ecosystem example of convergent evolution, in this case be- has been destroyed or severely degraded (Yensen tween organisms from two different kingdoms. 1992] McCUNE ROSENTRETER: TEXOSPORIUM SANCTI-JACOBI 333

Perhaps the morphology of the spores is inti- MOSELEY, R. C. GROVES. 1990. Rare, threatened and mately related to Texosporiums ability to survive endangered plants and animals of Idaho. Natural Her- over a broad area despite its rarity. Two possible itage Section, Idaho Department of Fish and Game. Boise. functions for the fungal coat are providing resistance NADVORNIK, J. 1942. Beitrage zur Kenntniss der aus- to excessive drying and protecting the spore during sereuropdischen coniocarpen Flechten. Annales My- passage through the gut of an animal. cologici 40: 133-139. Texosporium is also potentially valuable as an PELLANT, M. 1990. The cheatgrass-wildfire cycle-are there any solutions?, pp. 11-18. In E. D. McArthur et indicator of long periods without overgrazing and al. (eds.), Proceedings-Symposium on Cheatgrass In- fire in sagebrush steppe communities. Although its vasion, Shrub Die-off, and Other Aspects of Shrub rarity and inconspicuousness lessen its utility as a Biology and Management. U.S.D.A. Forest Service general indicator of range condition, it may be one General Technical Report INT-276. Ogden. of a collection of species that in various combina- RABINOWITZ, D., S. CAIRNS T. DILLON. 1986. Seven forms of rarity and their frequency in the flora of the tions indicate disturbance history. However, we need British Isles, pp. 182-204. In M. E. Soule (ed.), Con- to learn much more about the dynamics of biotic servation Biology. Sunderland. crusts and their initial reaction and resilience to ROSENTRETER, R. 1986. Compositional patterns within various kinds of disturbances before we can fully a rabbitbrush (Chrysothamnus) community of the Ida- ho Snake River Plain, pp. 273-277. In E. D. McArthur appreciate Texosporiums place in arid ecosystems B. L. Welch (eds.), Proceedings-Symposium on the of the West. Biology of Artemisia and Chrysothamnus, Provo, , July 9-13, 1984. U.S.D.A. Forest Service General ACKNOWLEDGMENTS Technical Report INT-200. Ogden. SMITH, C. W. 1990. Toward an inventory of lichens of We appreciate the assistance of Charis Bratt, Steve Pinnacles National Monument, pp. 159-168. In C. van DeBenedetti, Ann DeBolt, Dennis Desjardin, Patricia Muir, Riper III et al. (eds.), National Park Service Trans- Sherry Pittam, William Reese, James Sleznick, Leif Tibell, actions and Proceedings Series No. 8, Examples of William Weber, and the curators of the herbaria contacted. Resource Inventory and Monitoring in National Parks Partial funding was provided by the Bureau of Land Man- of California. National Park Service, , D.C. agement, Boise District Office, Idaho. TIBELL, L. 1984. A reappraisal of the of Cal- iciales. Nova Hedwigia 79: 597-713. A. VAN HOFSTEN. 1968. Spore evolution of the LITERATURE CITED lichen Texosporium sancti-jacobi (Cyphelium sancti- EGAN, R. S. 1987. A fifth checklist of the lichen-forming, jacobi). Mycologia 110: 553-558. lichenicolous and allied fungi of the continental United TUCKERMAN, E. 1883. New western lichens. Bulletin of States and Canada. THE BRYOLOGIST 90: 77-173. the Torrey Botanical Club 10: 21-23. HITCHCOCK, C. L. A. CRONQUIST. 1973. Flora of the WEBER, W. A. 1967. A synopsis of the North American Pacific Northwest. Seattle. species of Cyphelium. THE BRYOLOGIST 70: 197-201. IDAHO NATIVE PLANT SOCIETY. 1991. Results of Seventh WHISENANT, S. G. 1990. Changing fire frequencies on Annual Idaho Rare Plant Conference. February 12- Idahos Snake River Plains: ecological and manage- 13,1991. Boise. ment implications, pp. 4-10. In E. D. McArthur et al. LAWREY, J. D. 1989. Lichen secondary compounds: ev- (eds.), Proceedings-Symposium on Cheatgrass In- idence for a correspondence between antiherbivore and vasion, Shrub Die-off, and Other Aspects of Shrub antimicrobial function. THE BRYOLOGIST 92: 326-328. Biology and Management. U.S.D.A. Forest Service McCuNE, B. 1992. Status of a globally ranked (G2) rare General Technical Report INT-276. Ogden. lichen species, Texosporium sancti-jacobi. Coopera- YENSEN, D. 1982. A grazing history of southwestern Ida- tive Challenge Cost Share Project, Final Report. Bu- ho with emphasis on the Birds of Prey Study Area. reau of Land Management, Boise District Office. Boise. U.S.D.I. Bureau of Land Management. Boise. STOR Texosporium sancti-jacobi, a Rare Western North American Lichen Author(s): Bruce McCune and Roger Rosentreter Source: The Bryologist, Vol. 95, No. 3, (Autumn, 1992), pp. 329-333 Published by: American Bryological and Lichenological Society Stable URL: http://www.jstor.orgistablc13243492 Accessed: 07/06/2008 15:48

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