Robert E. Magill

Bryophyte Flora of the Huon Peninsula, Papua New Guinea

Meesia triquetra (Richter) Ångstr. is the only species of the family Meesiaceae occurring in Western Melanesia and New Guinea. Two collections are from high elevation wetland areas, where the plant presumably has a similar habitat ecology on wet soils as in its northern localities. Documented list of boreal to temperate northern hemisphere bryophyte species having disjunct occurrences in New Guinea, list of bipolar species, and list of widely distributed species are presented. Most of disjunct species and bipolar species are either plants of high elevation open and rocky habitats or wetland habitats such as shore meadows or bogs in New Guinea. Widely distributed species occur either in habitats created by man’s activities, or are plants of open or shaded rocky habitats, preferably cliffs.

Insolation and photoperiodic control of tree development near the equator

Tree development alternates between periods of rest (dormancy), shoot growth, and flowering. At temperate latitudes, the seasonality of tree development (= phenology) is determined mainly by the annual course of temperature. However, 100 yr ago Klebs (1914) observed that in a glasshouse saplings of European beech (Fagus sylvatica) were dormant during the short December days, but when exposed to continuous illumination in a ‘light chamber’ their resting buds openedwithin 4 wk and 15 leaves expanded during the subsequent 4-month-long period of continuous shoot growth (Supporting Information Notes S1). In the glasshouse the increase in day length in January induced bud break of dormant saplings in February. Klebs concluded from his many experiments that the autumnal decline in ‘light quantity’ (duration9 intensity) induces bud dormancy, and in January the increase in light quantity, sensed by dormant buds, breaks dormancy and triggers bud break of leafless saplings in a glasshouse. He recognized that for any given latitude day length and light intensity are coupled, because solar intensity varies significantly through the year as the sun’s path in the sky changes with the season. Implicitly, ‘light quantity’ is synonymous with ‘daily insolation’, the measure of integrated solar intensity and day length to be used in this paper (Calle et al., 2010). Subsequent studies, in which seedlings of many temperate tree species were exposed to experimental variation in day length, confirmed Klebs’ observations, but largely ignored his conclusions (Notes S1; Garner & Allard, 1923; Wareing, 1956; Romberger, 1963).Wewill use the term ‘photoperiodic control’ when referring to the control of tree development by the seasonality of daily insolation. While knowledge of photoperiodic control of dormancy in small experimental trees expanded, photoperiodic responses of mature trees received little attention (Romberger, 1963). Many years later, we observed in tropical forests at low latitudes that the phenology of many trees is highly correlated with seasonal variation in insolation (Rivera & Borchert, 2001; Rivera et al., 2002). The large size of trees precludes experimental confirmation of such field observations, but the strong correlations between seasonal variation in insolation and synchronous development of many tree species are, in fact, the results of the large-scale, long-term natural experiment conducted during the evolution of tropical trees (Calle et al., 2010). These correlations were not recognized in the past (Van Schaik et al., 1993; Thomas & Vince-Prue, 1997; Jackson, 2008). InCentral American semi-deciduous forests, a dry-season lasting from December to May alternates with a 6-month-long rainy season. Tree phenology is determined mainly by photoperiod or rainfall seasonality. Photoperiodic control is indicated by synchronous bud break or flowering of conspecific trees at the same time each year. The increase in insolation around the spring equinox induces flushing or flowering of leafless trees during the dry season (Rivera et al., 2002; Elliott et al., 2006) and its autumnal decline causes flowering of trees with mature foliage during the late rainy season (Rivera & Borchert, 2001). In other deciduous species, the timing of synchronous bud break of leafless trees varies from year to year with the first rains of the wet season, and during the dry season irrigation causes bud break within a few days (Borchert, 1984; Williams et al., 1997). At the equator, where day length is constant, many trees leaf out at irregular intervals, but others do so at the same time each year (Borchert et al., 2005a). There is no consensus regarding the environmental signal that causes synchronous greening. Seasonal variation in irradiance (Van Schaik et al., 1993), sunrise or sunset time (Borchert et al., 2005a), sunlight (Huete et al., 2006), solar radiation (Myneni et al., 2007; Morton et al., 2014) and high solar intensity (Renner, 2007; Yeang, 2007) have been considered.Most studies ignore that bud break preceding synchronous greening of tropical forests must be caused by an environmental signal perceived some weeks before leaf emergence (Klebs, 1914). The only environmental variable known to induce synchronous tree development near the equator is daily insolation, in short ‘insolation’ (Calle et al., 2009, 2010; L€ uttge, 2009; Guan et al., 2013).

A revision of Orthostichella (Neckeraceae)

Abstract Orthostichella Müll. Hal. is a genus of nine species (O. capillicaulis, O. hexasticha, O. longinervis, O. muelleri, O. pachygastrella, O. pandurifolia, O. rigida, O. versicolor and O. welwitschii) found only in tropical and subtropical regions of the New World and Africa. One species (O. hexasticha) is restricted to the Caribbean, one (O. pachygastrella) is found only in the continental regions of the New World, two (O. capillicaulis and O. pandurifolia) are restricted to continental Africa, and one (O. longinervis) is found only in Madagascar and the Mascarene Islands. The other species occur in both Africa and the New World. Orthostichella is predominantly epiphytic and often grows in dense, pendent masses. It has a complex morphology with creeping primary stems or stolons, and erect or pendent, stipitate or evenly foliose secondary stems that are irregularly branched. It lacks a stem central strand and its axillary hairs are usually reddish throughout. Its branches often end in filiform attenuations or stolons. The stolons, stems and branches can abruptly transform from one structure to another, or they can seamlessly intergrade one into another. The leaves are often spirally ranked, they have elongate, smooth, firm-walled leaf cells and weakly developed alar cells. The costae in Orthostichella are wildly variable. In some species most leaves are ecostate, however, some leaves can be found with double or single costae. In other species most leaves have a single or double costa, but ecostate leaves can also be found. In one species (O. longinervis) the leaves always have long, single, subpercurrent costae. Orthostichella has elongate-flexuose, roughened setae, ovoid to short-cylindrical capsules, long-rostrate opercula and mostly hairy, cucullate calyptrae. The Orthostichella peristome is diplolepideous and reduced. Exostomes and endostomes are yellowish white and nearly the same length. The more or less linear exostome teeth are lightly, horizontally striate on the dorsal (outer) surface at base. The endostome has a low basal membrane with filamentous, narrowly perforate segments and cilia are usually absent. Orthostichella appears best placed in the Neckeraceae by virtue of its neckeroid peristome, creeping stolons, stipitate stems with differentiated stipe leaves, foliose pseudoparaphyllia and leaves with weakly developed alar cells. Within the Neckeraceae Orthostichella seems best placed near Porotrichum, but the genus appears isolated by virtue of its non-complanate leaves that are often arranged in spiral rows. Additional new combinations include: Orthostichidium quadrangulare (Schwägr.) n. comb., Orthostichidium pentastichum (Brid.) n. comb. and Hildebrantiella phleoides (Desv. ex Brid.) n. comb.

An integrated assessment of the vascular plant species of the Americas

The vascular plants of the Americas Botanical exploration in the Americas has a history that stretches back for half a millennium, with knowledge assembled in diverse regional floras and lists. Ulloa Ulloa et al. present a comprehensive and integrated compilation of all known native New World vascular plant species (see the Perspective by Givnish). This compilation, in a publicly available, searchable database, includes 124,993 species—about one-third of the worldwide total. They further present details of the distribution of species across families and genera, the geographical foci of diversity, and the floristic relationships between regions. The rate of plant species discovery in the Americas averages almost 750 annually, so this valuable resource will continue to grow. Science, this issue p. 1614; see also p. 1535 A database of all known New World vascular plants holds almost 125,000 species, with the highest concentration in Ecuador. The cataloging of the vascular plants of the Americas has a centuries-long history, but it is only in recent decades that an overview of the entire flora has become possible. We present an integrated assessment of all known native species of vascular plants in the Americas. Twelve regional and national checklists, prepared over the past 25 years and including two large ongoing flora projects, were merged into a single list. Our publicly searchable checklist includes 124,993 species, 6227 genera, and 355 families, which correspond to 33% of the 383,671 vascular plant species known worldwide. In the past 25 years, the rate at which new species descriptions are added has averaged 744 annually for the Americas, and we can expect the total to reach about 150,000.

A review of the moss genus Hypnella

Hypnella is a neotropical genus offour species: H. leptorrhyncha, H. pallescens, H. pilifera, and H. diversifolia. These species can be divided into two groups (H. leptorrhyncha-H. pilifera and H. pallescens-H. diversifolia) in which the members of each group are more or less spatially isolated. The familial affinities of Hypnella lie with the Sematophyllaceae. Neohypnella, difering from Hypnella only by its lack of a furrow on the dorsal surface of the exostome, is placed in the synonymy of Hypnella. A new lectotype for the genus is selected. The genus Hypnella includes pleurocarpous mosses of neotropical distribution characterized by a non-complanate habit, lack of a central strand in the stem, undifferentiated alar cells, long narrow leaf cells with 3-6 papillae over the lumens, double cos- tae, mitrate calyptrae, elongated setae that are pa- pillose to scabrous at the apex, and double peri- stomes marked by transverse striae on the dorsal surface of the exostome and the complete lack of endostomal cilia. In the past Hypnella has usually been aligned with the Hookeriales. The group was first described by Miiller (1851) as a section of Hookeria. MUiller dis- tinguished the section within Hookeria by its long narrow leaf cells and densely imbricate habit that showed no sign of being plano-complanate. Jaeger (1877) gave the section generic status and excluded all species with smooth leaf cells from the group. Jaeger retained Hypnella in his family Hookerieae (sic), a placement Brotherus (1907) followed when he further characterized the genus by its double cos- tae, transversely striate exostome teeth, lack of a central strand in the stem and the absence of en-

A Reexamination of Globulinella (Musci; Pottiaceae)l

A study of available specimens of Globulinella has resulted in a re- alignment of some species and a significant range extension. Globulinella globi- fera (Hampe) Steere is reported for the first time to the United States. Gyro- weisia benoistii Ther. is transferred to Globulinella and Gyroweisia obtusifolia Broth. is removed from synonymy. During the summer of 1973 a small pottiaceous moss was collected on a calcareous outcrop in the Chisos Mountains of Big Bend National Park, Brewster County, Texas. Several months later another specimen was collected on calcareous silt in the desert be- low the mountains. The specimens were identified as Globulinella globifera, resulting in a considerable range extension for the species. A similar extension, recently reported for G. peruviana (Sharp & Bowers, 1975), indicated the need for a critical reexamina- tion of the genus. The nomenclatural history of Globulinella began when Hampe (1870) described two species, Seligeria globifera and Trichostomum obtusifolium, from specimens col- lected by Strebel in Veracruz, Mexico. Several years later Miiller (1897) published the genus Globulina for a single species, G. boliviana. In a short note under the description, Miiller suggested Seligeria globifera Hampe might be placed in Globulina. In 1902 Brotherus made the combination, Globu- lina globifera (Hampe) C.Miill., attributing it to Miiller. At the same time he provided a new name for the later homonym Trichostomum obtusifolium Hampe, i.e., Gyroweisia obtusifolia Broth. Williams (1916) added a third species to Globulina, when he de- scribed G. peruviana for a small moss collected by Cook and Gilbert near Araranca, Peru. The first reexamination of the species of Globulina was undertaken by Hilpert (1933) in his study of Trichostomaceae. Hilpert recognized G. globifera and G. peruviana as

A review of Dimerodontium (Fabroniaceae)

Abstract A revision of Dimerodontium recognizes three species: D. mendozense, D. balansae and D. pellucidum, all found in southern South America and the last two also in South Africa, mostly epiphytic or saxicolous.

Neckeropsis pocsii (Neckeraceae, Musci), a new species from Comoro Islands

Neckeropsis pocsii Enroth & Magill sp. nov. (Neckeraceae, Musci) from Mayotte, Comoro Islands, is described and illustrated. It resembles N. disticha (Hedw.) Kindb. in habit but differs in the generally wider leaf bases, more strongly serrulate to crenate leaf apices, slightly longer setae rendering the capsules fully exserted, and filiform post-fertilization paraphyses.

Mitthyridium micro-undulatum subsp. comoroensis subsp. nov. from Mayotte

Mitthyridium micro-undulatum (Dixon) H. Robinson subsp. comoroensis Reese subsp. nov. is described and illustrated from Mayotte, Comoros. The subspecies micro-undulatum is also illustrated. A collection of Mitthyridium from the island of Mayotte, Comoros-the first record of the genus from the Comoros-is similar to but distinct from the related M. micro-undulatum (Dixon) H. Rob- inson, from the Seychelles. The Comoros specimen is here described as a new subspecies of M. micro- undulatum.

A new species of Encalypta (Encalyptaceae) from west Texas

Abstract Encalypta texana is a new, gymnostomous species from west Texas, U.S.A. It differs from other small, gymnostomous, southwestern United States species of Encalypta in having oblong to elliptical, broadly acute, ventrally papillose leaves with subpercurrent costae and basally recurved margins, irregularly fringed calyptrae, non-furrowed capsules and finely pitted spores.