Lecanopteris

Abstract: The rhizomes of all species in the fern genus Lecanopteris Reinw. contain galleries (hollow chambers) that serve as domatia (homes) for ants. Some aspects of the biology of these species have been elucidated clearly, e.g., adaptations linked to the facultative, co-ecological association between Lecanopteris species and ants have been well established. Other aspects such as the evolutionary relationships between Lecanopteris and other genera of the Polypodiaceae as well as among the thirteen species in Lecanopteris remain widely debated. Diverse leaf and rhizome features have provided numerous autapomorphic characters for diagnosing species and describing subgenera, but there are few synapomorphies to establish reliable interspecific alliances. DNA sequences of the rbcL gene and the trnL-F non-coding region were obtained to test hypotheses of evolutionary history for Lecanopteris and related taxa. Data from each DNA region were considered separately and in combined analyses. The phylogeny obtained...

Abstract: Thylacopteris is the sister to a diverse clade of polygrammoid ferns that occurs mainly in Southeast Asia and Malesia. The phylogenetic relationships are inferred from DNA sequences of three chloroplast genome regions (rbcL, rps4, rps4‐trnS IGS) for 62 taxa and a fourth cpDNA sequence (trnL‐trnF IGS) for 35 taxa. The results refute previously proposed close relationships to Polypodium s.s. but support suggested relationships to the Southeast Asiatic genus Goniophlebium. In all phylogenetic reconstructions based on more than one cpDNA region, we recovered Thylacopteris as sister to a clade in which Goniophlebium is in turn sister to several lineages, including the genera Lecanopteris, Lepisorus, Microsorum, and their relatives. Goniophlebium and allies comprise a significant component of vascular fern epiphytes in the rain forests of Southeast Asia and Malesia. The relationships of the genus Thylacopteris as at the base of the clade comprising the genera Goniophlebium, Lecanopteris, Lepisorus, Microsorum, ...

Abstract: The structure and diversity of fern spores, based on SEM studies, are assessed in relation to general evolutionary trends and systematics. A review of spores of myrmecophytic ferns includes SEM figures of eight species and the ant Iridomyrmex cordataus . The diversity, especially in Lecanopteris spores, is correlated with other characters indicating systematic differences of the species. Convergence is shown in the echinate spores of the neotropical Solanopteris and those of the paleotropical Drynaria and Selliguea . Evidence for adaptation of spore structure to transport by ants is especially clear in the development of filamentous elements, unique among pteridophytes, in Lecanopteris mirabilis . These demonstrate an unusual labile nature of the wall, and provide insight into the functional role of intricate surface formation of spores.