Systematic Revision of Elaphoglossum (Dryopteridaceae) in French Polynesia, with the Description of Three New Species

Species descriptions and a key for the nine species of Elaphoglossum (Dryopteridaceae) in French Polynesia are provided. Three new species are described: E. austromarquesense from the southern Marquesas Islands, E. florencei from Raiatea and Moorea, and E. meyeri from Rapa. Each species is illustrated by a line drawing of the habit, and spore images using a scanning electron microscope. Images of scales, one of the most important diagnostic characters in the genus, are also included. © 2008 The Linnean Society of London

Sex and the Single Gametophyte: Revising the Homosporous Vascular Plant Life Cycle in Light of Contemporary Research

Homosporous vascular plants are typically depicted as extreme inbreeders, with bisexual gametophytes that produce strictly homozygous sporophytes. This view is promulgated in textbook life cycles despite ample evidence that natural populations of most species regularly outcross. We review research on a variety of mechanisms, including genetic load, asynchronous production of eggs and sperm, and pheromonal control of gamete production, that actively promote heterozygosity in ferns and lycophytes. Evolution of the land plants cannot be reconstructed without accurate depictions of the unique life cycle that has helped make ferns the second most diverse lineage of vascular plants on Earth. With revised illustrations and definitions, we provide scientists, educators, and students with a contemporary understanding of fern and lycophyte reproduction, revealing them as evolutionarily dynamic and exploiting a wide range of mating systems

Monograph of the Neotropical Fern Genus Polybotrya (Dryopteridaceae)

The genus Polybotrya (Dryopteridaceae) includes 35 species of neotropical ferns. It is distinguished by 1) strongly dimorphic leaves with fertile leaves that resemble skeletons of the sterile, photosynthetic ones; 2) usually high-climbing stems that are covered with scales; and 3) a unique stem anatomy with 5 to 12 circularly arranged meristeles, each surrounded by a black sclerenchymatous sheath, with numerous tiny leaf traces arching between adjacent meristeles. The center of diversity of the genus is the Andes, where 23 species occur, 12 of which are endemic. The coastal mountains of southeastern Brazil are notable because they contain 5 species, all endemic. The range of Polybotrya is from Chiapas, Mexico, southward through Central America; the West Indies; northern South America southward along the Andes to Bolivia and Paraguay and eastward to the Guiana Highlands; the Amazon River basin and the Matto Grosso; and southeastern Brazil. Species of the genus typically inhabit wet, shaded, primary tropical forests from sea level to 2500 m, most often occurring at middle altitudes between 500 and 2000 m. Polybotrya is divided into three subgenera: 1) Soromanes, leaves simply pinnate and veins anastomosing; 2) Sorhifolia, leaves simply or twice pinnate and veins free, close, and parallel; and 3) Polybotrya, leaves decompound and veins free. Polybotrya cervina, a species usually included in Polybotrya, is removed to the monotypic genus Olfersia (Moran 1986). Polybotrya is related to dryopteroid genera such as Arachniodes, Cyclodium, Maxonia. Olfersia, and Polystichopsis. Carl Christensen, the father of modem fern taxonomy, observed (1916) that Polybotrya may have arisen from Maxonia because both have high-climbing stems and strongly dimorphic leaves. The morphological and anatomical evidence presented here suggests that Polybotrya may have evolved instead from a Cyclodium-like ancestor. I chose Polybotrya for study because two aspects of the genus immediately intrigued me: its strongly differentiated sterile and fertile leaves and its long, creeping hemiepiphytic stem (Fig. 1). Since these features evolved separately in unrelated fern genera, studying Polybotrya might well provide insight into broader questions of fern evolution. Polybotrya was suited to monographic study because the number of species (35), all of which are neotropical, was manageable. Finally, no previous monographic work had been done on Polybotrya and many problems of nomenclature and identification remained to be solved.published or submitted for publicationis peer reviewe

Sandstone Rock Crevices, an Exceptional New Habitat for Thelypteris simulata

Volume: 70Start Page: 136End Page: 13

Pleopeltis coenosora (Polypodiaceae), a New Species from Peru

Volume: 20Start Page: 311End Page: 31

The Asplenium trichomanes Complex in the United States and Adjacent Canada

Volume: 72Start Page: 5End Page: 1

Cystopteris tennesseensis in Illinois

Volume: 72Start Page: 93End Page: 9

Cystopteris X illinoensis: A New Natural Hybrid Fern

Volume: 72Start Page: 41End Page: 4

Coryphopteris simulata

Pteridophyte

Flora of Taiwan, Second Edition, Volume 1. Pteridophyta, Gymnospermae

Volume: 85Start Page: 66End Page: 6