Showing papers in "American Fern Journal in 1998"

Old World Climbing Fern (Lygodium microphyllum), a Dangerous Invasive Weed in Florida

Abstract: -Lygodium microphyllum, a native of the warm and wet regions of the Old World, was first detected to be naturalized in southeastern Florida in 1965. This fern has become an aggressive invader of natural vegetation in many different habitats that are frequently dominated by the weed. Aerial surveys conducted in 1993, 1995, and 1997 detected increasing densities and continued expansion of its distribution in Florida. The fern is expected to continue to increase in Florida and could spread by spores to suitable habitats in Texas and Mexico. No effective method of control for the plant exists. Lygodium microphyllum (Cav.) R. Br. (Schizaeaceae), or Old World climbing fern, is native to wet tropical and subtropical regions of the Old World. It has become a serious weed in southeastern Florida, where it is increasing in density and range. In the present paper we discuss the ecological problems associated with the fern and its naturalization and spread, probable origin, and potential to spread, and the control attempts to date. The companion paper (Pemberton, 1998) discusses the potential of biological control to reduce populations of this plant and to limit its spread. The fern's native distribution and taxonomic relations, both essential information for a biological control program, are also reported.

The Potential of Biological Control to Manage Old World Climbing Fern (Lygodium microphyllum), an Invasive Weed in Florida

Abstract: -Lygodium microphyllum is native to wet tropical and subtropical Africa, Asia, Australia, and the Pacific islands. The genus Lygodium is taxonomically isolated and has only one native species in North America. Specialized natural enemies of L. microphyllum are predicted to exist that can be safely employed to control the fern in Florida, where it is a severe problem. Lygodium microphyllum (Cav.) R. Br., or Old World climbing fern, is a serious weed in southern Florida, as described in the companion to this paper (Pemberton and Ferriter, 1998). In an attempt to reduce populations of this plant and to limit its spread, a biological control research effort is being initiated. The theory of biological control and the suitability of this approach to reduce and manage L. microphyllum are discussed. To help lay the groundwork for the biological control effort, the native range and taxonomic relations of the fern are defined. This information is used to plan and conduct surveys for natural enemies as well as research to define the potential host ranges of candidate biological control agents. The question of whether insects and other natural enemies can be expected to be associated with L. microphyllum is addressed.

Distribution of Tree Ferns (Cyatheaceae) across the Successional Mosaic in an Andean Cloud Forest, Narino, Colombia

Abstract: Approximately eleven species of tree ferns (Cyatheaceae, Dicksonia, and Lophosoria) occur in the cloud forest of La Reserva Natural La Planada, Narifo, Colombia. We used 500 m2 (50X10 m) plots, 10 each in primary forest, secondary forest, and abandoned pasture, to measure the density and species distribution of tree ferns. Abandoned pasture and secondary forest had approximately equal tree fern densities, with density in primary forest significantly lower. Species richness was highest in secondary forest due to the mixture of early and late successional species. Pasture and secondary forest habitats were dominated by Cyathea caracasana; higher diversity recorded in abandoned pasture is due to high relative abundances of two subordinate species: Lophosoria quadripinnata and Dicksonia sellowiana. Primary forest was dominated by a single species, Cyathea planadae, with very low relative abundance of the other species recorded. The dominance transition during regeneration appears to begin after approximately 20 years of re- growth, suggesting that the disturbance mosaic and the resulting environmental heterogeneity in Andean forests is important in maintaining species diversity in tree ferns. Two recommendations for conservation emerge: 1) Conservation of tree fern diversity depends on the maintenance of a variety of successional habitats within the forest; 2) Tree ferns are an important component of species that colonize abandoned open sites in Andean forests. Their rapid growth rate and pref- erence for open habitat suggest that some tree fern species may be useful in restoration strategies in cloud forests.

The Effect of Sterilization and Storage Conditions on the Viability of the Spores of Cyathea delgadii

Abstract: Tests were conducted to evaluate the effects of various sterilization procedures on spores of Cyathea delgadii stored under different conditions with the intent of developing a strat- egy of ex-situ spore conservation of this declining species. Although the percentage of germination after two years of storage was relatively low for all storage and sterilization parameters, dry storage at -12?C resulted in the best survival rate. Elimination of bacterial and fungal contaminants was best when the spores were washed, treated with calcium hypochlorite, incubated, filtered, and washed again before sowing on medium containing Nystatin. The spores of some tree ferns in the Cyatheaceae lose their viability after a few weeks of storage (Page, 1979). The viabilility of Cyathea delgadii Sternb. spores is already decreased after only two months storage at 12?C and low humidity (Randi and Felippe, 1988a) and percent spore germination is signif- icantly decreased after six months of storage under the same conditions (Mar- condes-Ferreira and Felippe, 1984). In general, it is advisable to store fern spores at low temperature and low humidity, sometimes with the use of des- iccators (Dyer, 1979a). More recently, storage in darkness at room temperature and high humidity (imbibed) has been advised for some species (Lindsay et al., 1991). Before storing imbibed spores in the laboratory or before germination of spores stored dry, there is the need to sterilize them. Several chemicals have been used for this purpose (Dyer, 1979b), and either sodium hypochlorite (NaOCl) or calcium hypochlorite (Ca(OCl2)J4H2O) are the most commonly used. Unfortunately, most treatments that kill contaminant fungi and bacteria also reduce fern spore germination. Different concentrations of chemicals and duration of application have been used. Before germination, it is advisable to incubate the spores in darkness for a period of time: the fungi and bacteria start to grow and become more sensitive to the chemicals used for sterilization (Voeller, 1964; Schedlbauer, 1976). The objective of this investigation was to study different sterilization meth- ods and storage conditions in order to develop a procedure for maintaining a source of viable spores of Cyathea delgadii for "ex situ" conservation, because this species is rapidly disappearing from the Brazilian forests as consequence of commercial exploitation.

Germination of Spores of the Lycopodiaceae in Axenic Culture

Abstract: Spores from four species of Huperzia, three species of Lycopodiella, and three species of Lycopodium were germinated in axenic culture. The ten species included species with subterra- nean mycorrhizal gametophytes and others with surficial photosynthetic gametophytes. The germi- nation of spores from species with mycorrhizal gametophytes was slow, but much faster than pre- viously reported. It occurred in the dark in a few months for most species instead of years as reported by Bruchmann (1910). Although species of Lycopodiella are expected to have rapid germination, spores from two species had slow germination. It appears that not all the species of the Lycopodi- aceae with photosynthetic gametophytes exhibit rapid spore germination as reported by Treub (1884). Germinating the spores of the Lycopodiaceae in axenic culture is difficult. It generally takes a considerable length of time and the percentage of germi- nation is low (Whittier, 1977, 1981; Whittier and Webster, 1986). Efforts over the years to germinate these spores under more natural conditions (i.e., on soil) have demonstrated that spores of the Lycopodiaceae fall into two classes according to how rapidly they germinate (Bierhorst, 1971). The spores of spe- cies with subterranean, mycorrhizal gametophytes germinate slowly (Bruch- mann, 1910; Barrows, 1935) and those of species with photosynthetic, surficial gametophytes germinate more rapidly (DeBary, 1858 (see Chamberlain, 1917, or Barrows, 1935) and Treub, 1884, 1888). Studies on the germination of spores from species of the Lycopodiaceae with mycorrhizal gametophytes provide limited information (Table 1). Bruchmann (1910) germinated the spores of Lycopodium selago L. (Huperzia selago (L.) Bernh. ex Schrank & Mart.), L. annotinum L., and L. clavatum L. in soil cul- tures. Barrows (1935) investigated spore germination with Lycopodium com- planatum L. var. flabelliforme Fernald (L. digitatum Dill. ex A. Br.) and ob- tained 16% germination after one year. More recent attempts to germinate these spores have been carried out in axenic culture (Table 1) but less than 0.1% of the spores germinated. It is probably advantageous for spores forming subterranean gametophytes to germinate slowly and be down in the soil before gametophyte development starts. Indications from earlier studies (Whittier, 1977, 1981; Whittier and Web- ster, 1986) are that spores producing mycorrhizal gametophytes only germinate in the dark, which would stop germination until the spores are covered by soil. However, why these spores of the Lycopodiaceae need long times in the dark before they germinate and why they have such low percentages of germination is not understood. In other pteridophytes with mycorrhizal gametophytes, spore germination is more rapid and can exceed 50% after a few months in axenic culture (Melan and Whittier, 1990; Whittier and Braggins, 1994).

Cyathea planadae, a Remarkable New Creeping Tree Fern from Colombia, South America

Abstract: A new species within the Cyathaceae is described from the mid-elevation cloud for- ests of the Andes in southwestern Colombia. Cyathea planadae N.C. Arens & A.R. Smith has fragile, ephemeral, sphaeropteroid indusia surrounding inframedial to medial sori, which are typ- ical of many Cyathea; however it is unusual in possessing a creeping stem. Decumbent stems (above-ground rhizomes) bearing adventitious roots and buds give rise to narrow, glabrous upright shoots upon which three or four twice-pinnate-pinnatified fronds are typically displayed. Cyathea planadae is very common and patchily distributed in the understory of primary forest habitats in montane forests. The species is also noteworthy for an apparent association with an ant species, which appears to feed from pads of tissue at the base of the pinnae. Tree ferns of the family Cyatheaceae are a common, abundant, and ecolog- ically important part of the flora of montane and premontane wet forests in the Andes of Colombia. Taxonomic note of this group was first made in the mid eighteenth century with initial floristic surveys of the Andes by Spanish botanists such as Jose Celestino Mutis (Diaz-Piedrahita, 1991). A taxonomic revision of Cyathea and related genera in the Andes was undertaken in the 1960s and 1970s by Rolla Tryon and his students. Recent and ongoing studies

SEM Studies on Vessels in Ferns. 5. Woodsia scopulina

Abstract: -Scanning electron microscopy (SEM) studies of macerations reveal that vessels are present in both roots and rhizomes of Woodsia scopulina. In rhizomes, there is less differentiation between lateral walls and end walls. In both root and rhizome vessels, there are perforation plates both on end walls and on lateral walls; because of the grouping of tracheary elements, more than one cell facet at a cell tip can qualify as an end wall. Lateral wall perforation plates are less specialized than end wall perforation plates. Lateral wall perforations often have porose pit membranes, whereas end wall perforations often lack pit membrane remnants, especially in roots. Tracheids may be present in addition to vessels, but because one cannot see all facets of a cell and many cells are broken or overlain, absence of perforation plates on all tracheary elements cannot be established with certainty. Woodsia obtusa has less specialized vessels: end wall perforation plates have porose pit membranes, and lateral perforation plates are apparently lacking. Greater specialization of vessels characterizes adaptation to more seasonal habitats in angiosperms; this correlation appears to apply to ferns as well. Woodsia scopulina tends to occupy sites of higher latitude or altitude than those of W. obtusa. Vessels have been reported for ferns in the case of Pteridium (Russow, 1873; Bliss, 1939; Carlquist and Schneider, 1997a), and these reports have been widely accepted. Vessels were described in roots of Marsilea by White (1961, 1962), and the vessels he illustrates have clearly defined perforation plates. Vessels were claimed by Gwynne-Vaughan (1908) for several genera of ferns, but that report was discounted by Bancroft (1911). White (1962) suggested there might be vessels in ferns other than Pteridium and Marsilea, but he was appropriately cautious, because demonstration of presence or absence of pit membranes in end walls of tracheary elements by means of light microscopy, the tool available to him, is difficult or impossible. However, White (1962) singled out Woodsia (Dryopteridaceae) as a genus likely to have vessels (he designated them as "presumptive vessels") in roots, although not in rhizomes. White cited eight Woodsia species has having slight differentiation of end walls (as compared to lateral walls) on tracheary elements, two as having medium differentiation, and one as having a high degree of differentiation. One of the two species cited with medium differentiation of the end walls was W scopulina D.C. Eaton. Because SEM is a definitive tool for showing presence or absence of membranes in pits on end walls and lateral walls of fern tracheary elements, we have elected to study with SEM the ferns most likely to have vessels based on differentiation between end walls and side walls as seen with light microscopy. In Pteridium (Carlquist and Schneider, 1997a), Woodsia ilvensis (L.) R. Br. (Carlquist and Schneider, in press), Microgramma nitida (J. Sm.) A.R. Sm. (Schneider and Carlquist, submitted), and Phlebodium and Polystichum This content downloaded from 157.55.39.25 on Mon, 25 Jul 2016 04:27:12 UTC All use subject to http://about.jstor.org/terms AMERICAN FERN JOURNAL: VOLUME 88 NUMBER 1 (1998) (Schneider and Carlquist, 1997), we have established the presence of welldifferentiated end wall perforation plates. We have also found lateral-wall perforation plates in these genera, although determination of what is an end wall and what is a lateral wall is not as easy in ferns as it is in angiosperms, where vessels are mostly in clear vertical series and do not form dense groupings, as they do in these ferns. In Woodsia obtusa (Spreng.) Torr. (Carlquist et al., 1997), we found end walls on tracheary elements with porose lysis of pit membranes, and therefore we claimed perforation plates as present; we did not see perforation plates on lateral walls in this species. Woodsia scopulina is of potential interest because the degree of differentiation of end walls of tracheary elements, according to the data of White (1962), is greater than in W. obtusa. If greater differentiation between end walls and lateral walls is present in W. scopulina, other tracheary element features that differ from those of W obtusa are potentially of interest. In our study of W obtusa (Carlquist et al., 1997), we were unable to determine the full extent of perforation plates because sections were used. Use of macerations in the present study permits better understanding of the three-dimensional nature of vessel elements. The fact that a number of ferns now prove to have vessels makes each genus and species in which vessels occur of potential interest. White's (1962) suggestion that vessels might be absent in rhizomes of Woodsia proves not to be true for at least some species. However, this finding leads to the question of whether rhizome vessels may be less specialized and more tracheidlike than root vessels. Also of potential interest is whether tracheids are present in addition to vessels in Woodsia. Differences among species with respect to vessel specialization of vessels are also of potential ecological interest, because more specialized perforation plates in monocotyledons and dicotyledons are associated with more highly seasonal availability of moisture (Carlquist, 1975). Woodsia scopulina occurs in areas that are cool to cold in winter, and where freezing might be a factor in water availability; warm summer temperatures and drought may characterize at least some of the localities. Brown (1964) documented the range of W scopulina from southern Alaska down the Rocky Mountains to southern California and Arizona, as well as along the northern part of the Great Plains: South Dakota, northeastern Minnesota, northern Saskatchewan, Ontario, and the Gaspe area of Quebec. He cited isolated stations in Arkansas and the Appalachian Mountain portions of North Carolina, Tennessee, Virginia, and West Virginia. MATERIALS AND METHODS The plants of W scopulina used in this study were collected in the only known locality in Arkansas, Magazine Mountain in Logan County, during October, 1996. The collectors were Don Crank, Jim Peck, and Robbin Moran. Material was sent to us in fresh condition by George Yatskievych. Segments of roots, rhizomes, and petioles of several plants were preserved in 50% aqueous ethyl alcohol. Although in our study of Woodsia obtusa (Carlquist et al., 1997) we sectioned 18 This content downloaded from 157.55.39.25 on Mon, 25 Jul 2016 04:27:12 UTC All use subject to http://about.jstor.org/terms SCHNEIDER & CARLQUIST: VESSELS IN WOODSIA SCOPULINA

Architecture of the Spermatozoid of Selaginella australiensis

Abstract: -Ultrastructural details of the mature pre-released spermatozoid of Selaginella australiensis are presented with a three-dimensional model based on these data. This sperm cell is highly elongated and coils for nearly three revolutions. A parallel band of spline microtubules runs around the periphery of the cell and forms the structural framework along which the four organelles are aligned. Numbers of microtubules in the spline begin with one at the tip of the cell and progressively increase to 19 toward the cell posterior. The locomotory apparatus consists of two staggered monomorphic basal bodies, referred to as the anterior and posterior basal bodies, and their corresponding axonemes. Typically, no remnant of the lamellar strip is visible in the mature spermatozoid. The anterior mitochondrion occupies over 1/ gyres at the front of the cell and as such is the largest organelle. It is inserted immediately behind the anterior basal body and underlies the posterior basal body/axoneme for over one revolution. The posterior axoneme is retained within the cell body over the spline and anterior mitochondrion. The nucleus extends approximately one gyre and is situated between the anterior mitochondrion and a smaller posterior mitochondrion. At the rear of the cell is a plastid that contains two large juxtaposed starch grains. Similarities of this cell with other lycophytes include the staggered monomorphic basal bodies and increase in spline microtubules from front to back. Commonalities with bryophyte and charalean spermatozoids include cellular organization and shape, and the lack of a lamellar strip in the mature cell. Selaginella is a key taxon in understanding the early events in land plant diversification (DiMichele and Skog, 1992). The fossil record of this phylogenetically significant genus dates back to the Carboniferous, making Selaginella second only to Lycopodium in geological age (Bierhorst, 1971). Living representation of this lycopsid is extremely diverse, with over 700 species worldwide (Webster, 1992; Valdespino, 1993). Yet, the precise placement of Selaginella in the plant kingdom is unclear. The paucity of detailed comparative studies on anatomical and ultrastructural features of lycopsids, and especially the ligulate taxa, has confounded resolution of relationships among these basal plant lineages (Garbary and Renzaglia, in press). Clearly, additional studies on this taxonomically complicated and phylogenetically crucial genus are warranted. Spermatogenesis has proven to be a rich source of phylogenetic information (Garbary et al., 1993; Mishler et al., 1994; Duncan et al., 1997; Maden et al., 1997). The major limitations in using male gametogenesis for phylogenetic reconstructions are the low numbers of organisms that have been investigated and the incomplete data sets for those taxa that have been observed. In bryophytes, much attention has been placed on elucidating the microanatomy of This content downloaded from 157.55.39.147 on Wed, 20 Apr 2016 04:41:16 UTC All use subject to http://about.jstor.org/terms AMERICAN FERN JOURNAL: VOLUME 88 NUMBER 1 (1998) the locomotory apparatus or blepharoplast (Carothers and Rushing, 1988; Renzaglia and Duckett, 1991). Few studies of developmental processes and mature cell structure have been undertaken (Vaughn and Renzaglia, in press). In pteridophytes, even fewer organisms and structural features have been documented than in bryophytes (Duckett 1973; 1975; Duckett and Bell, 1977). Ultrastructural observations of Selaginella spermatogenesis is limited to one species, S. kraussiana (Kunze) A. Braun. In gross morphological features, this spermatozoid bears an uncanny resemblance to those of bryophytes. Although an idealized reconstruction of the mature cell for this species was presented by Robert (1974), many details of the cellular organization remain unclear. Thus, we undertook an ultrastructural investigation of the mature sperm cell of a second species of Selaginella, S. australiensis Baker. Descriptions of precise structural features and a three-dimensional reconstruction of the cell based on these data are presented. Comparisons are made with motile gametes from a wide range of green plants, with emphasis placed on identifying similarities and differences among biflagellated gametes of Selaginella, Lycopodium sensu lato, bryophytes and Charales. MATERIALS AND METHODS Selaginella australiensis was collected in the rainforest on Mount Wilson, Blue Mountains, New South Wales, Australia, in October, 1991. Plants were maintained in the greenhouse and monitored for sporangial production. Mature microsporangia were dissected and placed on filter paper moistened with distilled water in petri plates. The plates were sealed with parafilm and placed in an incubator at 20?C with a 12 hr light/dark cycle. After 10 days, the cultures were examined daily until swimming sperm cells were detected. Because of differing rates of microgametophyte development among the several microsporangia per plate, cultures harvested at the first sign of mature spermatozoids generally contained all stages of spermatogenesis. Microsporangia were lifted from the filter paper and placed in microfuge tubes containing 6% glutaraldehyde in 0.05 M Pipes buffer (pH 7.4). Microspores were liberated from sporangia and gently cracked with the end of a flame-sealed Pasteur pipet. Without mechanical disruption of spore walls, fixative and resin will not penetrate the microgametophyte. After immersion in the primary fixative for 2-4 hr, the microspores were washed four times in 0.1 M cacodylate buffer (pH 7.2) and post fixed in 2% Os04 in the same buffer for 2 hr. Prior to withdrawing solutions, the spores were pelleted in a microcentrifuge for 30 sec. After washing with distilled water, the spores were "en bloc" stained in 1.0% aqueous uranyl acetate for 16 hr at 4?C. The specimens were rinsed in distilled water, dehydrated in a graded acetone series, replaced by propylene oxide, infiltrated slowly over approximately one week with 1:1 Spurrs/Embed 812 resin, embedded and cured at 60?C for 16 hr. Thin sections were collected on copper grids and post-stained with 2% uranyl acetate in ethanol and basic lead citrate for five min each. Grids were observed on a Philips 201 or Hitachi 7100 TEM. 2 This content downloaded from 157.55.39.147 on Wed, 20 Apr 2016 04:41:16 UTC All use subject to http://about.jstor.org/terms RENZAGLIA ET AL.: SPERMATOZOIDS OF SELAGINELLA All micrographs of cross sections are oriented as if viewing from the anterior of the cell, i.e., from the front of the MLS. In such an orientation, the triplet and double microtubules in basal bodies and flagella overlap in a counterclockwise direction. References to right and left in the text refer to this orientation.

Fern Spore Morphology and Spore Rain of a Preserved Cerrado Region in Southeast Brazil (Reserva Biologica e Estacao Experimental de Moji Guacu, Sao Paulo)

Abstract: -This paper presents a morphological and phenological study of the spores of the fern species of a preserved cerrado area, the Reserva Biol6gica e Estagao Experimental de Moji Guagu (Sao Paulo State), Brazil. Of the 40 fern species found in the Reserve, 9 occur in the cerrado, 35 in the gallery forest that surrounds the cerrado, and four species are common to both. Twentytwo species have monolete spores and 18 trilete spores. Spore rain was collected monthly at four localities: open cerrado, cerrado, gallery forest, and marsh. Spores of 16 species were present in the spore rain. The highest percentage of spores was found in the marsh and the lowest in the open cerrado. In all four localities, the highest percentage of spores was observed in the summer months of January and February. Pteridophyta can be found in all types of habitats (Raghavan, 1991), including very dry regions that may be subjected to periodic fires. The cerrado, Brazilian savanna, originally covered about 22% of the country, extending from the Equator to the Tropic of Capricorn. Much of the cerrado is subjected to prolonged and often severe winter drought lasting up to four months (Alvim and Araujo, 1952; Eiten, 1972). Esteves and Felippe (1985) described nine species of pteridophyta in the cerrado of the Reserva Biologica de Moji GuaSu, Sao Paulo state: Adiantum serratodentatum Willd., Anemia flexuosa (Sav.) Sw., A. raddiana Link, Doryopteris concolor Langsd. & Fisch., Microgramma squamulosa (Kaulf.) de la Sota, Pleopeltis angusta Humb. & Bonpl. ex Willd., Polypodium hirsutissimum Raddi, P. latipes Langsd. & Fisch., P. polypodioides (L.) Watt var. minus (F6e) Weath. These nine fern species are either drought resistant or the sporophytes are present only during the wet season. This cerrado area surrounds a gallery forest in which 35 fern species were found by Simabukuro (1995). Simabukuro et al. (1994) mentioned 36 species, but it was discovered later that Thelypteris linkiana (C. Presl) R.M. Tryon had been mistakenly identified; also Thelypteris brevisora (Ros.) Ponce is now known as Thelypteris dutrai (C.Chr. ex Dutra) Ponce. Four cerrado species were also present in the gallery forest: Microgramma squamulosa, Pleopeltis angusta, Polypodium latipes, and P. polypodioides var. minus. Thus, 40 species have been identified in the Reserva. Simabukuro et This content downloaded from 207.46.13.176 on Mon, 20 Jun 2016 05:57:57 UTC All use subject to http://about.jstor.org/terms SIMABUKURO ET AL.: CERRADO SPORE RAIN al. (1994) mentioned that Dicranopteris flexuosa (Schrad.) Underw., Pityrogramma trifoliata (L.) R.M. Tryon, and Pteridium aquilinum (L.) Kuhn var. arachnoideum (Kaulf.) Brade were invaders (weeds) of the gallery forest. In the marsh around the gallery forest were found Lycopodiella cernua (L.) PichiSerm., Pityrogramma calomelanos (L.) Link, Thelypteris interrupta (Willd.) Iwats., and Thelypteris serrata (Cav.) Alston. Only a few papers have dealt with spores of pteridophyta in pollen rain in Brazil: They were detected in very small quantities during August-October in a cerrado area in Aparecida, Goias (Salgado-Labouriau, 1973); they were also detected near the center of the city of Rio de Janeiro, with a predominance of Adiantum (Barth, 1975). This paper presents: 1) a detailed morphological study of the spores of the fern species from the gallery forest; 2) use of this spore data plus the morphological study previously published (Esteves and Melhem, 1992) to correlate the fern species of the Reserva Biologica de Moji Guagu with spore rain analyses over a period of one year. This is the first study of this kind carried out in Brazil. METHODS AND MATERIALS STUDY AREA (Fig. 1).-All 35 fern species were collected 1984-1994 on monthly visits to the gallery forest of the Reserva Biologica e Esta,ao Experimental de Moji Guagu (Simabukuro et al., 1994; Simabukuro, 1995). The species were identified by Dr. Paulo Windish (Sao Jose do Rio Preto, SP), Alexandre Salino (Belo Horizonte, MG), and Dr. Jefferson Prado (Sao Paulo, SP). The Reserve (22?18'S, 47?11'W) is located in Moji Guagu, State of Sao Paulo, Brazil (Eiten, 1963). The gallery forest is situated along the Cortado and Fundao streams. In addition to the gallery forest, the Reserve includes cerrado and marsh, and is surrounded by Pinus sp. plantations (Mantovani and Martins, 1993). In the cerrado, nine fern species occur (Esteves and Felippe, 1985). Forty total species of pteridophyta occur in the Reserve. SPORE MORPHOLOGY.-The morphology of the spores of the nine fern species that occur in the cerrado were studied previously (Esteves and Melhem, 1992). Of the gallery forest species, the majority of the spores are from herbarium specimens collected in the Reserva Biologica de Moji Guacu by Aldo Klein (AK), Eliana Akie Simabukuro (EAS), and Luciano Mauricio Esteves (LME), which are deposited in the herbarium of Universidade Estadual de Campinas, Brazil (UEC). The spore morphology of 31 species was studied (Table 1). Of the 35 species mentioned in Simabukuro (1995), five species (Microgramma squamulosa Pleopeltis angusta, Polypodium hirsutissimum, Polypodium latipes, P polypodioides var. minus) that also occur in the cerrado have been studied previously (Esteves and Melhem, 1992). The spores were treated by the acetolysis method (Erdtman, 1971) with the period of treatment adjusted for each species. The slides were gelatin-glycerin mounted according to Kisser (Erdtman, 1971). The spores were measured in 115 This content downloaded from 207.46.13.176 on Mon, 20 Jun 2016 05:57:57 UTC All use subject to http://about.jstor.org/terms AMERICAN FERN JOURNAL: VOLUME 88 NUMBER 3 (1998) 1:21.000 :.'.' :. -. i ...

Fungal Associations with Isoetes Species

Abstract: The fungal associations present in the roots and corms of four species of Isoetes found in Rajasthan, India, are described. Fungal fruiting bodies and chlamydospores are assigned to the mycorrhizal genus Glomus, and the septate branched intracellular mycelium is assigned to the genus Rhizoctonia of the Deuteromycotina.

Taxonomy and Distribution of Adiantum trapeziforme and A. pentadactylon

Abstract: Data concerning the taxonomy and geographic distribution of Adiantum trapeziforme L. and A. pentadactylon Langsd. & Fisch. are presented. Both species have been confused in the past and the distinctness between them is discussed. During the preparation of a taxonomic revision of Adiantum (Pteridaceae) in Brazil, the senior author noticed some problems involving the delimitation and distribution of A. trapeziforme and A. pentadactylon. The former species was described by Linnaeus (1753) and lectotypified by Lellinger (1977) based on an illustration by Sloane (1707: t. 59). Sloane's illustration does not clearly show the diagnostic characters for this species and it might be confused with A. pentadactylon, a related taxon. Adiantum pentadactylon was described by Langsdorff and Fischer (1810) and its type material (probably an isotype) is at G (photos BM, SP). This material resembles A. trapeziforme but represents a different species. Over the years, several authors have treated these species in different ways, sometimes erroneously. Hooker (1851) mentioned that both species belonged to the A. trapeziforme group, which is characterized by: "Fronds tripinnate or decompound; sori almost invariably short, equal or nearly so, rarely continu- ous or elongated, as in A. speciosum and fumarioides." He did not, however, clarify the differences between these species. Fee (1869) cited Glaziou 2318 (B, P) as A. trapeziforme f. B A. pentadactylon. Glaziou's material was collected in Rio de Janeiro and is a typical example of A. pentadactylon. According to Baker (1870) in Flora Brasiliensis, A. pentadactylon is a syn- onym of A. trapeziforme. Nevertheless, the material cited by Baker, located at BM (Glaziou 438) and BR and P (Glaziou 1754), are clearly A. pentadactylon, and were collected in Rio de Janeiro. Christ (1900) described A. trapeziforme var. incisum Christ based on spec- imens (Ule 51, 195) from the State of Santa Catarina, Brazil. The variety was said to differ in its less glaucous pinnules, thinner tissue, segments lobed more than half way to the base, and numerous lobes (6-7 on each side of the seg- ment) usually bifurcate and obtuse. The syntype at P (Ule 195), however, is A. pentadactylon.

A New Species of Hecistopteris from Guyana, South America

Abstract: First collected in Surinam more than 150 years ago, Hecistopteris pumila is known only from tropical America, from a few collections in herbaria, which may be due to its incon- spicuous size. A second species, H. pinnatifida, was recently described from Ecuador. Hecistop- teris kaieteurensis, the third species for this genus, is described from Guyana. For 150 years, Hecistopteris was a monotypic genus consisting of the sole species H. pumila (Spreng.) J. Sm. known only from tropical America. The genus differs from others in the Vittariaceae by having small (up to ca. 6 cm long), simple, subsessile fronds that lack a pronounced midrib and are apically or laterally lobed or cleft. The plants usually reproduce vegetatively by root proliferations, as illustrated by Kramer (1990, p. 275), on mossy tree trunks. A second species in the genus, H. pinnatifida R.C. Moran & B. 0llgaard, was recently described from Ecuador (Moran and 0llgaard, 1995, p.180). We have found a third species, here named Hecistopteris kaieteurensis, while surveying the trees of Kaieteur National Park in Guyana. The main fea- ture of the park is a waterfall with a straight drop of 741 ft. The area at the top of the falls is forested with occasional open "guiana type" savannas that are characteristic of the Roraima formation. The forests are generally along the creeks and rivers and have a canopy ranging from 20-60 meters in height. A small patch of Hecistopteris kaieteurensis was found growing in moss on a trunk of a tree approximately 1.5 m above the base. Other trees were not ex- amined at the time to see the extent of the population. According to Jefferson

The Effect of Surface Sterilization on Cultures of Ceratopteris richardii Gametophytes

Abstract: Gametophytes of Ceratopteris richardii were grown as single-spore and double spore cultures on agar to test the effects of surface sterilization of spores (with bleach) and contamination of cultures on growth and sexual expression. Hermaphroditic gametophytes were larger in double- spore than in single-spore cultures for cultures derived from both untreated and sterilized spores, whereas gametophytes were larger in single-spore than in double-spore cultures in contaminated cultures. However, gametophytes did not differ in size between double-spore and single-spore cultures derived from surface sterilized spores. The greatest antheridiogen response was observed in cultures with no treatment and the least antheridiogen response was observed in contaminated cultures. A standard method of preparing gametophyte cultures from spores involves the surface sterilization of spores using a dilute bleach (hypochlorite) solution (e.g., Banks et al., 1993). The purpose of this method is to reduce the effects of other organisms on treatments during experimental investigations of ga- metophyte growth and development. We, however, have been concerned that bleach may affect the extracellular matrix of the spore. An effect on the extra- cellular matrix of the spore could significantly affect investigations of aspects of gametophyte development such as antheridiogens, as antheridiogens must first affect the extracellular matrix of a spore or gametophyte cell to have an effect on spore germination and gametophyte development. To address the effects of contamination and surface sterilization of spores, we cultured ga- metophytes of the leptosporangiate fern Ceratopteris richardii Brongn. using untreated and surface sterlized spores, culturing untreated spores in both axe- nic and contaminated media.

Cibotium xheleniae Hyb. Nov. (C. chamissoi x C. menziesii; Cyatheaceae): A Naturally Occurring Hybrid from Oahu, Hawaii

Abstract: The hybrid between Cibotium chamissoi and C. menziesii is described from the Ha- waiian island of Oahu. Distinctions between the hybrid and its parents are detailed. The potential existence of other hybrids among the four Hawaiian Cibotium species is discussed. Intensive investigations of Hawaiian pteridophytes over the past decade have revealed many interspecific hybrids, both published (Ranker, 1992; Wag- ner, 1993; Wagner et al., 1995; Palmer, 1997) and unpublished. These are rec- ognized usually by their coexistence with the parental species, morphological intermediacy, mostly sporadic occurrence, and more or less abortive spores. Here, I describe a recently discovered natural hybrid between two of the more common Hawaiian species of tree ferns of the genus Cibotium. The genus Cibotium includes about ten species ranging from Assam through southeastern Asia to Borneo and the Ryukyus, as well as other Pacific Islands, Mexico, and Central America (Kramer, 1990), with four species recognized in Hawaii (Palmer, 1994). The present paper describes a distinctive hybrid be- tween Cibotium chamissoi Kaulf.and C. menziesii Hook., presently known only from the island of Oahu, but probably more widespread on other Hawai- ian islands.

Status of Schizaea pusilla in New York, With Notes on Some Early Collections

Abstract: The occurrence of Schizaea pusilla in New York is restricted to eastern Long Island (Suffolk County), where populations occur in moist to wet humus-rich depressions within a dy- namic system of shifting dunelands. An historical account of the earliest collections and currently known populations is presented.

Spore Morphology of Botrychium lunarioides

Abstract: Spore morphology was examined in the rare fern Botrychium lunarioides with the scanning electron microscope. Surface topography of the spore walls confirms the placement of B. lunarioides in the subgenus Sceptridium. Botrychium is a widespread genus of eusporangiate ferns classified within the family Ophioglossaceae. Clausen (1938) originally divided this genus into three subgenera based on vernation, dissection of the leaf blade, and gameto- phyte shape. Presently, four subgenera are recognized (Tryon and Tryon, 1982; Tryon and Lugardon, 1991): Botrychium, Japanobotrychium, Osmundopteris, and Sceptridium. Although some investigators (Kato, 1987 and discussion therein; Sahashi, 1976) have raised these subgenera to generic level, Wagner (1990) considered it best to retain the more conservative classification, at least for the present. Of particular use in placement of species within the proper subgenus has been spore morphology, in particular surface topography (Tryon and Lugardon, 1991). The scanning electron microscope (SEM) has proven a particularly use- ful tool for such studies. Botrychium lunarioides (Michx.) Sw. is a species restricted to the south- eastern United States. According to Warren H. Wagner (pers. comm.), "It is one of the rarest ferns in the United States, and not one botanist in a thousand has seen it." However, Watkins (1992) recently completed a status survey of this species in Alabama and while doing so discovered a number of new lo- calities. Also, Do et al. (1996) have shown this species to be more common in eastern Texas than previously thought. The species is considered to belong within the subgenus Sceptridium (Wagner and Wagner, 1993). Wagner (1992) gave an analysis of the distinctive features of B. lunarioides that differentiated it from other members of subgenus Sceptridium, and he placed it in a separate section, Hiemobotrychium. Thus, in spite of its distinctive characters, B. lu- narioides was still considered to belong to subgenus Sceptridium. However, no confirmatory evidence from spore morphology has been available. The pur- pose of this study is to provide that information. A recent study (Skoda, 1997) recommended placing B. lunarioides in a new monotypic genus as Holubiella lunarioides (Michx.) Skoda, based on a number of morphological features including tracheidal idioblasts in the leaf stalks. It remains to be seen how this proposal will be received by other pteridologists. For the purposes of the present manuscript, we shall follow the commonly

A Millenium and a Half of Fern Illustrations

Abstract: The history of fern illustration is part of the history of western botanical illustration. Drawings of ferns intertwine with the art of the 1500 years this story spans. To concentrate pri- marily on this history as it is revealed in the published works over this time, an important theme becomes evident. As in so much scientific discovery, technological advances pave the way for a growth of knowledge and more accurate perception. The advances in botanical illustration are balanced between the growing knowledge and talent of the scientific artist and the growing skill of his technician allies, the woodblock cutter, the etcher, the engraver, the lithographer, and the photographer, and the growing strengths of the techniques themselves. The earliest existence of sound recognizable botanical art is affirmed on the walls of Egyptian tombs. However, no examples of the painted Greek and Ro- man art that were the source of almost all medieval copies have survived, although it is known from Greek and Roman chronicles that such art did exist. The earliest botanical volumes that have survived were herbals. They were books about medicinal plants with descriptions and drawings of the plants for identification. Among these plants were pteridophytes thought to have medic- inal properties. At least two species, Adiantum capillus-veneris and Polypodium vulgare, are in the earliest manuscript dealing with the depiction of plants that has come down to us today. The Codex Vindobonensis (Dioscorides, 512 AD), writ- ten and illustrated in Constantinople for the daughter of the Byzantine Em- peror of the West, is a copy of the Greek text De Materia Medica by Dioscor- ides, a first century AD physician and botanist. It is believed the original work consisted of paintings by Crateuas of some 500 plants, with the written part consisting of little more than their names and healing properties. According to the British art historian Wilfred Blunt, the Codex provided "the link be- tween classical and modern botany," and the paintings "the link between an- cient Greek and modern European botanical illustration" (Blunt and Steam 1994). From a facsimile of this text is a lovely, if somewhat primitive, illustra- tion of Adiantum capillus-veneris (Fig. 1). The manuscripts that made up the source of medical and botanical knowl- edge for the Medieval era were copies of the Codex and other classical mate- rial. For nearly 1000 years, the manuscripts produced were copies of copies made by illuminators with no or little botanical knowledge so that simplifi- cations, anthropomorphisms, and mistakes made the identification of plants nearly impossible (Apulius, 1481). This problem was compounded because maintaining a fidelity to previously printed words and images was one of the disciplines of Christianity in that period, which found heresy in the observa- tion of nature itself.

The History and Classification of the Farley Fern, Adiantum tenerum 'Farleyense'

Abstract: Adiantum tenerum 'Farleyense' is confirmed as a cultivar, not as a species or as a variety, as it is treated by some authors. The horticultural history of the fern is summarized, beginning on a Barbados sugar plantation. A neotype for the species name and a standard for the cultivar name are selected and justified. 'Farleyense' is compared morphologically with wild and cultivated Adiantum tenerum, as well as other maidenhair ferns, and is found to be morpholog- ically consistent with classification as a cultivar of A. tenerum. Seldom are cultivars as prominent through time, as well known, or as trou- blesome taxonomically as the Barbados Farley fern. Discovered on a horticul- turally sophisticated Barbados sugar plantation in the mid-nineteenth century, the Farley fern won instant acclaim in British horticultural circles, and was promptly named as a species. The fern was thought, with reservations, at the time to have been derived from Adiantum tenerum Sw., which is abundant wild and cultivated in Barbados. The Farley fern spread to gardens around the globe, and has remained popular ever since. Despite-or possibly on account of-its horticultural prominence, the fern's history, biology, classification, and nomenclature are befuddled throughout the literature dealing with it. The fern has been treated variously as a species, variety, and as a cultivar. The aim of the present account is to provide an historical background on the Farley fern, to correct nomenclatural problems, and to provide a systematic morphological appraisal of its classification as a cultivar of A. tenerum.

An Autoradiographic Investigation of Protein Synthesis During Rhizoid Differentiation in Pteris vittata

Abstract: In this autoradiographic study of protein synthesis during rhizoid differentiation in P vittata, total grain counts increase seven-fold, from 42 grains in the non-differentiated stage to 295 in the premitotic corona stage. This almost doubles to 624 in the postmitotic internally- segmented rhizoid stage (irc) and increases five times to 3,079 in the wheel stage that follows; the count then doubles to 6,120 grains in the later protrusion stage and approximately doubles again to 13,487 in the final young rhizoid stage. These results show that rhizoid initiation, differentia- tion, and growth are attended by significant increases in protein syntheses. Although the grain count over the cytoplasm increases seven-fold in the corona when compared to the non-differ- entiated cell, the relative percentage distribution for this compartment remains unchanged. How- ever, grain counts over the cytoplasm of postmitotic stages increase from 80% (irc) to 96% (wheel) to 97% (protrusion) and to 99% (young rhizoid) of the total count. In contrast, nuclear labeling reached a stationary phase in the irc and in the subsequent postmitotic stages. The first rhizoid in Pteris vittata L. is produced when the spore divides mitotically at germination; however, rhizoid formation may be more clearly observed later in gametophyte development, i.e., in the enlarged, vacuolated thallus cells that mature behind the regions of cell division and enlargement (Crotty, 1967). Increases in cytoplasmic RNA in the vicinity of the spore nucleus during primary rhizoid formation in Matteuccia struthiopteris (L.) Tod. were reported by Gantt and Arnott (1965). Extensive cytochemical studies of Pteris vittata by Crotty (1961, 1967) have provided detailed descriptions and analyses of the events at the light microscope level that accompany secondary rhizoid devel- opment, including RNA, protein, and polysaccharide syntheses. Additionally, these studies described a succession of developmental stages that occurred during the pre- and postmitotic rhizoid differentiation process (Fig. 1). Using a precise autoradiographic technique, Cohen and Crotty (1979) reported that the RNA in the anastomosing cytoplasmic strands around the nucleus of the corona (first stage of rhizoid differentiation) originated in the premitotic nu- cleus of this stage. In a later autoradiographic study, Cohen and Crotty (1990) demonstrated the existence of specific patterns of RNA synthesis in the stages of rhizoid differentiation in P vittata. The purpose of this study was to determine if protein synthesis during rhi- zoid differentiation, as measured by radioactive leucine uptake, could also be quantified and resolved into specific patterns. And, if so, can the results show a meaningful relationship to the earlier studies in P. vittata? In fact, the results of this investigation demonstrate that rhizoid differentiation is attended by