Calcium oxalate and sulphate‐containing structures on the thallial surface of the lichen Ramalina lacera: response to polluted air and simulated acid rain

Abstract

The formation of calcium-containing structures on the thallial surface of the lichen Ramalina lacera (With.) J.R. Laund. in response to air pollution and to simulated acid rain, was studied in in situ and transplanted thalli. In situ thalli were collected from an unpolluted site and transplanted to heavily polluted and less polluted sites for a 10 month period. Additional thalli were treated either with double distilled water or with simulated acid rain. Scanning electron microscopy and infrared spectrometry revealed that thallial surfaces of in situ R. lacera samples collected in unpolluted sites were covered with two kinds of calcium oxalate crystals: whewellite and weddellite. These aggregates of calcium oxalate crystals appear to disintegrate and provide a crystal layer on the thallial surface. Infrared spectroscopy of powder scraped from thallial surfaces of transplants, retrieved from non-polluted sites, showed the presence of whewellite and weddellite, whereas powders obtained from thalli retrieved from polluted sites contained whewellite, weddellite and gypsum. It is suggested that a certain fraction of the gypsum detected in crater-like structures in transplants from polluted sites and in thalli treated with simulated acid rain is endogenous and should be considered a biomineral.

Lichens and Particulate Matter: Inter-relations and Biomonitoring with Lichens

“…An additional case of low CVs for K was observed for Ramalina lacera in the North-Eastern part of Israel which has a Mediterranean climate. The CVs obtained for K in this lichen growing in an unpolluted site (HaZorea) were 0.10 (Garty et al 1997a), 0.07 (Garty et al 1998b), 0.08 (Garty et al 2001a), and 0.14 (Garty et al 2002a). Another study (Garty et al 1998a) yielded a CV of 0.09 for K, whereas the CVs for lithophilic elements such as Al, Si, Ti, and Fe were 0.27, 0.27, 0.25, and 0.21, respectively.…”

“…(Fig. 3.7), sometimes produced in great amounts in and on the thallial surface (Garty et al 2002a)? What about calcium sulfate crystals (Fig.…”

“…What about calcium sulfate crystals (Fig. 3.8) that emerge from the thallial surface of lichens exposed to SO 2 in polluted industrial sites (Garty et al 2002a)? Do we and can we eliminate such structures by 5-8 washings, sonication, and shaking in an aquatic medium and other drastic treatments and then determine chemical elements located in a "pure" organic association?…”

Developmental morphology of the flower of Anaphyllopsis americana and its relevance to our understanding of basal Araceae

“…Extracellular crystal deposition is a characteristic feature of many lichens (Garty et al 2002), gymnosperm species (Oladele 1982;Fink 1991;Pennisi et al 2001), and angiosperms (e.g., Franceschi and Horner 1980;Borchet 1984;Fink 1991;Kuo-Huang 1992;Berg 1994;Pennisi et al 2001). D' Arcy et al (1996) reported the presence of extracellular calcium oxalate crystals (referred to as oxalate packages) mixed with pollen in some members of Araceae, such as Anthurium, Calla, and Zantedeschia.…”

On the presence of extracellular calcium oxalate crystals on the inflorescences of Araceae

“…The presence of extracellular calcium oxalate crystals is a phenomenon that appears to be more or less widespread in plants. Extracellular crystal deposition on the epidermal surface is a characteristic feature of many lichens (Garty et al ., 2002) and gymnospermous species (Oladele, 1982; Fink, 1991a,b; Pennisi et al ., 2001). In angiosperms this phenomenon has been reported for Casuarinaceae (Berg, 1994), Draceana (Fink, 1991a; Pennisi et al ., 2001), Gleditsia (Borchert, 1984), Nymphaea (Franceschi & Horner, 1980; Kuo‐Huang, 1992), Sempervivum (Fink, 1991a; Vladimirova, 1996), and Stelis (Chase & Peacor, 1987).…”