This bibliography contains 395 entries, all the scientific publications of Warren H. Wagner, Jr. The bibliography is based on a list maintained by Prof. Wagner, with additional comments and entries by Dr. Florence S. Wagner and Dr. Richard Rabeler. It includes abstracts, ephemera, reports, and reviews. The bibliography is in rough chronological order of publication. Exact publication dates were found for most journal articles. However, month or estimated dates were used for other publications, especially books, which usually are not datable within a year. All the entries are contained in a searchable database now maintained by Florence S. Wagner. The database categorizes the publications according to their subject matter and includes the more or less exact publication dates that are the basis for the chronological list.

Genetic loads, estimated from sporophyte production by isolated gametophyte cultures, indicate mating systems of intragametophytic selfing in Campyloneurum angustifolium (in part), C. phyllitidis, Phlebodium aureum and Phymatosorus scolopendria, and intergametophytic mating in C. angustifolium (in part), Microgramma heterophylla and Polypodium pellucidum. Polyploidy characterizes the intragametophytic-selfing species, whereas the intergametophytic-mating taxa are diploid. The duplicated loci of polyploid taxa may mitigate the expression of recessive lethal alleles caused by intragametophytic selfing, whereas genetic load probably maintains the mating systems of the intergametophytically mating taxa. Enzyme electrophoretic patterns of fixed heterozygosity support allopolyploid origins of C. phyllitidis and P. aureum and confirm their intragametophytic mating systems. Antheridiogens, present in both groups, may promote intergametophytic mating in diploids through promotion of the early development of male plants in gametophyte populations and bisexuality in isolated gametophytes of polyploids if these gametophytes delay or do not attain insensitivity to their own antheridiogen. In the polyploids, antheridiogens may also alleviate low genetic variability through promotion of occasional outcrossing. The perennial, clone-forming habit of epiphytic Polypodiaceae increases the duration and the physical space occupied by derivatives of a single spore, thus expanding the chance of interaction with a later migrant. Genetic load, duplicated genes, and antheridiogens, together with a perennial and clone-forming gametophyte growth habit, interact to produce successful breeding strategies of these epiphytic species.

A significant portion of the stages of the life history of Botrychium, the gametophyte and juvenile sporophytes, are spent belowground. Surveys were conducted to determine the distribution and abundance of belowground gametophytes, juvenile sporophytes and gemmae of eight species of Botrychium. For each species, soil samples were collected in a 200 m² area, sifted through a series of soil sieves, and centrifuged to separate the lighter plant material. Only 40% of the soil samples contained belowground structures revealing a patchy distribution. The gametophytes of B. montanum are most dense, followed by B. mormo with 738 and 728 gametophytes m⁻² respectively. Botrychium hesperium also has a relatively high density of 478 gametophytes m⁻². Botrychium gallicomontanum is the least dense with 10 gametophytes m⁻². Botrychium campestre and B. gallicomontanum both have abundant gemmae and few gametophytes. The density of individuals in the belowground structure bank greatly exceeds the aboveground population. The size and health of the belowground structure bank is critical in sustaining the long-term aboveground population and in buffering it from extinction.

Recent fieldwork on Saba, Netherlands Antilles, has resulted in the discovery of nine fern species unrecorded for the island. All are known from other islands in the Antilles, as well as from other tropical areas.

A review of the literature regarding Hawaiian pteridophytes, examination of herbarium specimens, and much field work resulted in the need to publish two new varieties and to make thirteen new combinations.

Three new species (Adiantum squamulosum, Pteris boliviensis, and P. krameri) from South America are described and illustrated. We also provide a new name for an endemic species of Cheilanthes from Brazil and a new record of Pteris for Bolivia.

Resumo.—Três novas espécies (Adiantum squamulosum, Pteris boliviensis e P. krameri) da América do Sul são descritas e ilustradas. São também apresentados um nome novo para uma espécie endêmica de Cheilanthes do Brasil e um novo registro de ocorrência para Pteris na Bolívia.

A previous study examined the sexual expression of cultured gametophytes of the Hawaiian endemics Sadleria cyatheoides and S. pallida grown on mineral-enriched agar. In the present work, we conducted field studies on the sexual expression of natural populations of Sadleria spp. gametophytes. Our primary goal was to compare field-collected data to the laboratory-based data of the earlier study to assess if the laboratory data were an accurate reflection of what is occurring in nature. Our results suggested that for generally inferring mating systems operating in nature, agar-based laboratory studies of gametophytes lead to the same conclusions as would observations of field-collected gametophytes. For detailed studies of gametophyte sexuality and development, however, an agar-based medium produces significantly different results than what is found among natural populations, although this may be true for any lab-based study regardless of growth medium. Thus, we suggest caution in the use of agar as a growth medium, and the use of laboratory conditions in general, for studies of fern gametophyte sexual development.

An analysis of morphological data for 13 species with 33 characters and molecular data for 14 species from the chloroplast DNA intergenic spacer region trnL-F indicates that species of the genus Anemia fall into two well-supported subgenera, Anemiorrhiza and Anemia. In addition, one species of the genus Mohria appears to belong within Anemia. Although further study is required, these data support the relationships suggested by a previous study of fossil and extant representatives of the genus.

Data from three chloroplast genes (rps4 trnS spacer, trnL spacer; 1350 base pairs) for 27 of the recognized segregates show the Thelypteridaceae to be monophyletic and sister to an unresolved alliance of blechnoid, athyrioid, onocleoid, and woodsioid ferns. The family comprises two primary lineages, one phegopteroid, the other thelypteroid (including cyclosoroid). The phegopteroid lineage (Macrothelypteris, Pseudophegopteris, and Phegopteris) includes those elements that are the most dissected, lack adaxial grooves on the frond axes, and are generally morphologically the most distinct elements within the family. Within the thelypteroid-cyclosoroid lineage, three predominantly north-temperate subgroups, including Thelypteris s.s., form a free-veined clade that is in turn sister to the rest of the family. All segregates possessing x=36 (Cyclosorus sensu Smith, with predominantly anastomosing veins) form a strongly supported clade. Those groups with dysploid base chromosome numbers (x=27, 29, 30, 31, 32, 33, 34, 35) form a series of smaller clades basal to Cyclosorus s.l. Although our sampling is not yet sufficient to favor one classification over another, recognition of an intermediate number of genera may be the most reasonable taxonomic course.

Botrychium tunux and Botrychium yaaxudakeit, new species of moonworts currently known only from southern Alaska, are described and illustrated. These ferns are distinguished from B. lunaria, with which they have been confused, by allozyme data and their morphological characteristics. Ploidy levels of B. tunux (diploid) and B. yaaxudakeit (tetraploid) are inferred from allozyme patterns. A key to Alaskan moonworts is presented.

Isoëtes ×herb-wagneri, the interspecific hybrid between Isoëtes bolanderi and I. echinospora, is described. The epithet commemorates Warren (Herb) Wagner for the direction and help he provided to the author.

Botrychium alaskense W. H. Wagner & J. R. Grant is described as a new species from the interior of Alaska. It is an allotetraploid of B. lunaria (L.) Sw. × B. lanceolatum (S.G. Gmel.) Ångstr., the same species parentage that gave rise to the morphologically and isozymically distinct B. pinnatum H. St. John.

The varieties of Thelypteris pilosa have been recognized as the sole New World members of the subgenus Stegnogramma. Ferns of this species complex are common throughout central and southern Mexico, Guatemala, and Honduras and exhibit an intriguing temperate disjunction in Alabama. A significant amount of morphological variation exists in the Mexican taxa; it is unclear whether these differences are due to phenotypic plasticity or genetic factors. Two regionally sympatric morphotypes, varying from deltate to lanceolate fronds, occur throughout Mexico and have been described as var. major and var. pilosa, respectively. A more distinct type, described as var. alabamensis, is endemic to north Alabama rockhouse habitats and has been reported from only a single county. Data on ecology, spore morphology, gametophyte biology, and gross frond morphology support the elevation of T. pilosa var. alabamensis to specific status under the proposed name of T. burksiorum.

Two new alien pteridophytes have become established in the Hawaiian Islands since 1996, bringing the total of naturalized alien ferns to 32. Also, established alien species continue to spread onto new islands.