新疆阿尔泰山曲尾藓科2个中国新记录种

阿尔泰山是欧亚大陆最为宏伟的山脉之一,其中段的西南坡坐落于中国新疆境内,众多具温带性质的藓类植物分布于此。作者在对阿尔泰山进行苔藓植物区系调查过程中,发现了分布于阿尔泰山的喀纳斯自然保护区及布尔津县禾木乡的2个藓类植物中国新记录种——隶属曲尾藓科的短叶曲尾藓[Dicranum brevifolium(Lindb.)Lindb.]和卷叶小曲尾藓[Dicranella crispa(Hedw.)Schimp.]。由地理分布可知,短叶曲尾藓和卷叶小曲尾藓在中国皆为稀有种类。     

Sporophytes and gametophytes of Dicranaceae from the Santonian (Late Cretaceous) of Georgia, USA

A new species (Campylopodium allonense) of the moss family Dicranaceae is described for fossil sporophyte capsules and associated gametophytes from the late Santonian (Late Cretaceous) Buffalo Creek Member of the Gaillard Formation in central Georgia, USA. The sporophyte capsules are most comparable to those of the living genus Campylopodium. Sporangia are curved, cylindrical, and strumose, with an obliquely rostrate operculum, cucullate calyptra, and compound annulus. The peristome is haplolepidous with 16 dicranoid, apically bifid teeth that are vertically striate on the outer surface and asymmetrically trabeculate on the inner surface. Spores are spherical, alete, and finely rugose, and thus differ from the finely papillose spores of extant Campylopodium. Associated fossil gametophytes are consistent with the morphology of extant Campylopodium and have leaves with a broad sheathing base and a narrow blade. Spores identical to those in the sporangium occur on the leaf surfaces of one of the gametophyte specimens, providing circumstantial evidence that both sporophyte and gametophyte belong to the same species. Inadequacies of the moss fossil record have led to contrasting interpretations of the timing of evolutionary change in this lineage since the Paleozoic. Campylopodium allonense unequivocally provides the earliest evidence of Dicranaceae in the fossil record. This material, along with other fossil mosses from this late Santonian locality, indicates the presence of modern families of mosses in the Cretaceous. In a phylogenetic context, these fossils from two different subclasses imply that mosses were already diverse by the Late Cretaceous.     

Dicranum scottianum Turner (Dicranaceae): synonyms,a type and the correct author

Introduction. The moss Dicranum scottianum Turner, described based on material collected in Ireland by Robert Scott, is currently known from Europe and Macaronesia (Canary Islands and the Azores). The previously proposed authorship of ‘Turner ex Robt. Scott’ and lectotype for this name proved to be erroneous.

Methods. Over 60 herbarium specimens, including types, of D. scottianum and putative allies were examined with the aim of outlining the diagnostic features of the taxon or taxa concerned, and establishing any necessary synonymy.

Key results. The true authorship of Dicranum scottianum by Turner is re-established, and the name is effectively lectotypified with extant original material from BM. The type specimen and some subsequent collections of the species are described and illustrated. New nomenclatural synonyms of D. scottianum (namely Dicranum canariense Hampe ex Müll.Hal., D. erythrodontium Hampe ex Müll.Hal. and Orthodicranum allorgei J.J.Amann & Loeske) are detailed.

Conclusions. Dicranum scottianum is characterised by its asymmetrical leaves with one side of the leaf wider than the other, the difference in the angle of insertion of the lamina with respect to the costa (one side of the leaf is inserted at a 45° angle and the other is plane but widely incurved), the laminal cells that are thick-walled with quadrate or rectangular lumina (seen in cross-section), and the wide and deep costa that has two bands of stereids.