On Some Cases of Singular Behavior of the Moss Peristome

Spores potentially dispersed to longer distances are more tolerant to ultraviolet radiation: A case study in the moss genus Orthotrichum

“…Given that clouds can significantly reduce the UV amount (particularly UV‐B) reaching the ground (Németh et al., ), the spores of hygrochastic species would be exposed to lower UV doses in the moment of release. In addition, spores dispersed under wet conditions are less likely to be transported over long distances (Lazarenko, ; Mueller and Neumann, ). Thus, spores of xerochastic species are exposed to higher UV levels in nature, which matches well with the higher UV tolerance they showed in our study.…”

Spore liberation in mosses revisited

“…In addition to the restriction of spore release to dry conditions favourable for long distance wind dispersal (when the exostome teeth have adopted the ‘opening position’), this ‘flicking mechanism’ results in a release of a portion of spores at each transition of the wet to the dry state. Lazarenko (1957) studied the particular hygroscopic movements of peristome teeth in Timmia (Timmiaceae), which also occur at the transition of the wet to the dry state and stated that they can be considered as an ‘apparatus for the ejection of spores’. Lazarenko (1957) further concluded that such movements of exostome teeth result in a spore release directly after rain or dew, and therefore under conditions of sufficient moisture for the germination of the spores.…”

“… Lazarenko (1957) studied the particular hygroscopic movements of peristome teeth in Timmia (Timmiaceae), which also occur at the transition of the wet to the dry state and stated that they can be considered as an ‘apparatus for the ejection of spores’. Lazarenko (1957) further concluded that such movements of exostome teeth result in a spore release directly after rain or dew, and therefore under conditions of sufficient moisture for the germination of the spores. The spore release in B. populeum , as analysed in the present study, apparently combines both strategies: an ejection of spores directly after rain (when substrates in direct vicinity are wet), probably beneficial for population maintenance, and a continuous sifting out of spores under ongoing dry conditions (when the wind-distributed spores are thought to cover long distances), probably beneficial for gene flow to other populations and for colonization of new habitats.…”

“…A first reference to peristome teeth functioning as veritable spore catapults during desiccation is provided by Goebel (1895) , who interprets the extensions of the inner peristome teeth as catapulting organs in some diplolepidous Hypnaceae, Mniaceae and Bryum species. Steinbrinck (1897) , Lazarenko (1957) and Ingold (1959) further describe an active spore discharge by oscillatory or flicking movements of the outer peristome teeth occurring during the transition between the dry and wet state in a variety of genera, including Brachythecium (Brachytheciaceae). These authors analyse the ontogenetic development and anatomy of the exostome in these species and conclude that differential velocity of water uptake and loss in the outer and inner layer of the outer peristome teeth is responsible for the observed movements.…”

“…These authors analyse the ontogenetic development and anatomy of the exostome in these species and conclude that differential velocity of water uptake and loss in the outer and inner layer of the outer peristome teeth is responsible for the observed movements. Lazarenko (1957) provides line drawings of the inwardly bent outer peristome teeth in wet and dry states (constituting the closed capsule states) and of the temporary outwardly bent shape at the transition between the dry and wet state (constituting the open capsule state) in Timmia bavarica (Timmiaceae). The exact nature and modes of function of these movements were not further elucidated in these studies.…”