We provide the first and only comprehensive list of the ferns and fern allies of Bohol island, Philippines. This compendium is based on collections made from those of Cuming in 1841 to our recent survey of the karst forests of the Rajah Sikatuna Protected Landscape (RSPL) and vicinity during November, 2003 to February 2004. A total of 169 species in 63 genera and 27 families are reported here for the island, of which 91 species are new additions. Twenty-one species are Philippine endemics, five of which are previously known only from types or from very few collections. They are Ctenitis boholensis, C. humilis, Pteris whitfordii, Antrophyum williamsii, and Lomagramma merrillii. Bohol is the type locality of five fern names, namely, Ctenitis humilis, C. boholensis, Cyclosorus glaber and Thelypteris sevillana (= Pneumatopteris glabra), Cyclosorus boholensis Copel. (= Sphaerostephanos acrostichoides), and Diplazium petiolare. Two species in the genera Oleandra and Ctenitis and several specimens of Selaginella remain undetermined. Nineteen previously reported species have not been recollected or in some cases, their taxonomic identities are doubtful. Prior to this study, only one fern specimen from Bohol was accessioned at the Philippine National Herbarium (PNH). All historical collections are currently deposited in herbaria in the U.S.A. and Europe. Boholanos have successfully maintained the integrity of the wild populations of ferns, especially those species that are heavily collected in other parts of the Philippines for their ornamental value.

Leaf phenology in a population of the climbing fern Lygodium venustum was observed during a 31-month period in Veracruz, Mexico. The study site is located 100–200 m from the Gulf coast in the understory of a semideciduous lowland forest dominated by trees of Enterolobium and Ficus. Four leaf parameters: leaf growth of main and secondary axes, number of living leaves, leaf production and leaf mortality were scored monthly and correlated with two climatic factors: monthly mean temperature and precipitation. Sixty percent of the 37 individuals were supported on lianas, dead wood or shrubs. Smaller, unsupported plants with a height of less than 2.5 m had a mean number of 1.9 ± 0.27 leaves and produced 3.7 ± 0.52 leaves per year and did not become fertile. Over 50 % of the leaves died within the first 3 months, whereas over 10% lived for 12 to 30 months, resulting in a mean leaf life span of 5.6 ± 0.7 months. All leaf parameters were seasonal with the exception of the growth of the main axes. During the rainy season, leaf growth of secondary axes and leaf mortality increased approximately threefold and leaf production rose twofold. Correlations between climatic factors and leaf parameters were strongest within a time lag of one month. The strongest correlation was found between precipitation and the growth of secondary axes, indicating that water is the limiting factor. One to five dormant buds developed on 17.7% of the leaves contributing to 40.3% of the total leaf growth. The potentially long life span of the climbing leaves and the outgrowing dormant buds make this species a successful pioneer in disturbed vegetation and a competitive weed in Mexican vanilla plantations.

A treatment of Megalastrum (Dryopteridaceae - Pteridophyta) is provided for Bolivia. We recognize 14 species, of which six are described as new: M. alticola, M. aureisquama, M. bolivianum, M. ciliatum, M. marginatum, and M. rupicola. Also provided are notes and selected specimen citations for the other species, and a key to all Bolivian species of the genus.