Search

The biology of the weed goat’s-rue, Galega officinalis (Fabaceae), is reviewed. Introduced to Canada in the late 19th Century as an ornamental, it has become established at scattered localities and is spreading locally in southern Ontario. The plant is considered a noxious weed and is legally regulated in many jurisdictions due to the production of toxic alkaloids and its invasive characteristics. Primarily a weed of pastures, grasslands and perennial crops, it also displaces native vegetation in areas where it becomes established. Originally endemic in the Black Sea region, it was spread by humans through Europe and eastward to Pakistan as a herbal medicine. More recently it has been introduced widely as a forage and ornamental plant. As a folk remedy it has been used primarily to treat diabetes in humans and to enhance milk production in both humans and livestock. The plant has also been used as a forage by limiting consumption to early growth stages and the quantity ingested. Effective control has been achieved with 2,4-D, dicamba, tryclopyr, metsulfuron methyl and other herbicides. Goat’s-rue forms a highly specific nitrogen-fixing symbiosis with the soil bacterium Neorhizobium galegae symbiovar officinalis. Successful establishment of Goat’s rue in new regions depends on the co-introduction of plant and bacterium. The lack of long-distance dispersal adaptations, soil pH requirements and its symbiont dependency, reduces the ability of G. officinalis to spread into novel areas without anthropogenic activities. These constraints to establishment may facilitate management and eradication strategies.

The toxic legume plant, Galega officinalis, is native to the Eastern Mediterranean and Black Sea regions. This legume is considered to be a noxious weed, and its establishment in Canada may have resulted from ornamental planting and/or field trials. In its native range, a highly specific nitrogen‐fixing symbiosis with the bacterium, Neorhizobium galegae symbiovar (sv.) officinalis, is required for normal growth. In North America, nothing is known about the bacterial symbionts of G. officinalis. Our purpose was to determine the species and symbiovar identity of symbiotic bacteria associated with invasive plants of G. officinalis at five sites in the province of Ontario, Canada. Sequence analysis of four housekeeping (16S rRNA, atpD, glnII, and recA) and two symbiosis (nodC and nifH) genes showed that all 50 bacterial isolates from root nodules of G. officinalis at the five Canadian sites were identical to strains of N. galegae sv. officinalis originating either from Europe or the Caucasus. Plant tests indicated that soils collected from four Canadian sites without a history of agriculture or presence of G. officinalis were deficient in symbiotic bacteria capable of eliciting nodules on this plant. Collectively our data support the hypothesis of anthropogenic co‐introduction of G. officinalis and its specific symbiotic bacterium into Canada from the Old World. Factors that may limit the spread of G. officinalis in new environments are discussed.

The principal economic species of the genus Melilotus are white sweet-clover (Melilotus albus) and the extremely similar yellow sweet-clover (M. officinalis). Although they are widely recognized as distinct species, some influential references in North America reduce the former to a subspecific rank or even merely a conspecific synonym of the latter. Given their importance and the large numbers of germplasm collections, the doubt needs to be resolved. This review of relevant published evidence finds that in addition to the difference in floral colour, the traditional segregation of the two as distinct species is best supported by very strong reproductive barriers as well as divergent DNA sequences in three barcoding genes. Additional but weaker confirmation of separateness is provided by studies reporting differences in external morphology, biochemistry, seed protein profiles, karyotype and DNA microsatellites.

Altai Fescue, Festuca altaica Trinius, is an amphi-Beringian grass species also known from isolated, but widespread, locations in northeastern North America. The occurrence reported here, at the southern limit of eastern alpine habitat in Canada, represents the first for Nova Scotia.

The freshwater aquatic plant species Stratiotes aloides (water soldier) is native to Europe and central Asia, where it occurs in seasonally pleustonic or submergent populations. It has been imported into and cultivated in Canada as an ornamental plant. Recently it has been found escaped or persisting at five locations in south-central Ontario. A large population has established in the Trent River where it was likely present for several years prior to its discovery in 2008. The tendency of S. aloides to form dense floating mats can alter aquatic communities through competition and allelopathy, and is likely to inhibit navigation and recreational activities in the Great Lakes-St. Lawrence drainage system should it spread more widely in eastern North America. In Europe it is often abundant in ditches where it impedes flow and increases sedimentation. Moderate success at control has been achieved using herbicides (diquat) in the Trent River population, but manual removal has been inefficient. In spite of these control efforts, the plant is continuing to spread vegetatively downstream. An integrated management plan has been proposed to address its control by: (i) prevention of new introductions (pathway restriction); (ii) early detection and rapid response (newly established or found populations); and, (iii) eradication of known populations.

The toxic legume plant, Galega officinalis, is native to the Eastern Mediterranean and Black Sea regions. This legume is considered to be a noxious weed, and its establishment in Canada may have resulted from ornamental planting and/or field trials. In its native range, a highly specific nitrogen‐fixing symbiosis with the bacterium, Neorhizobium galegae symbiovar (sv.) officinalis, is required for normal growth. In North America, nothing is known about the bacterial symbionts of G. officinalis. Our purpose was to determine the species and symbiovar identity of symbiotic bacteria associated with invasive plants of G. officinalis at five sites in the province of Ontario, Canada. Sequence analysis of four housekeeping (16S rRNA, atpD, glnII, and recA) and two symbiosis (nodC and nifH) genes showed that all 50 bacterial isolates from root nodules of G. officinalis at the five Canadian sites were identical to strains of N. galegae sv. officinalis originating either from Europe or the Caucasus. Plant tests indicated that soils collected from four Canadian sites without a history of agriculture or presence of G. officinalis were deficient in symbiotic bacteria capable of eliciting nodules on this plant. Collectively our data support the hypothesis of anthropogenic co‐introduction of G. officinalis and its specific symbiotic bacterium into Canada from the Old World. Factors that may limit the spread of G. officinalis in new environments are discussed.

Japanese hedgeparsley is an annual (or sometimes biennial) forb introduced from Eurasia and found throughout much of the eastern United States and parts of extreme southern Canada. In North America, Japanese hedgeparsley is commonly found in ruderal habitats, such as roadsides, railroad rights-of-way, forest edges, and urban waste spaces. This species has not yet been listed as a noxious invasive, but its expanding populations have caused concern in several Midwestern states. The primary threat from Japanese hedgeparsley is its vigorous growth habit, which creates dense patches, and its dispersal ability, facilitated by its clinging, burr-like fruits. Some confusion on identification exists within theTorilisgenus, with similar species (particularlyT. arvensis) frequently misidentified in herbaria and the literature. Here, we review aspects of the etymology, taxonomy, biology, distribution, and management of Japanese hedgeparsley with the objective of increasing awareness of the potential threat posed by this species and its closely related congeners.

Darbyshire, S. J., Francis, A., Mulligan, G. A. and Graham, G. 2014. The Biology of Canadian Weeds. 153. Stachys palustris L. Can. J. Plant Sci. 94: 709–722. Marsh hedge-nettle, Stachys palustris, is a perennial Eurasian member of the mint family, which has become naturalized and weedy in some parts of eastern North America. It is a hexaploid member of a holarctic species complex, which differs morphologically from the primarily tetraploid North American forms. The production of fleshy tuberous rhizomes is the most significant distinctive feature. In Canada, it has been a weed of potato and root crops in Nova Scotia, New Brunswick and Prince Edward Island, although other crops and areas, such as soybean in Ontario, are also affected. Usually considered a wetland plant, it readily spreads into drier arable fields from adjacent ditches and wetlands. Several herbicides available for use in Canada have been found to provide limited long-term suppression in agricultural systems, with the best results obtained using combined pre-emergent and post-emergent applications.

The seed predation of woolly cupgrass (Eriochloa villosa), an invasive weed of East-Asian origin, was compared to that of yellow foxtail (Setaria pumila), an established and widespread weed, along a field border in Canada. The seeds of both species were glued to sandpaper cards and their removal in field conditions was recorded from July to September during the 3 years of 2009, 2010 and 2011. Predator exclusion cages allowed the evaluation of seed loss to be attributed to invertebrates, vertebrates and total seed loss due to predation for both species. Pitfall traps were installed and collected once in 2010 and during all the seed sampling dates in 2011 in order to evaluate predatory pressure from ground beetles and crickets. The average amount of seed loss that could be attributed to invertebrates was higher for S. pumila than for E. villosa, while the amount of seed loss that could be attributed to vertebrates was higher for E. villosa than for S. pumila in 2009 and 2010. The level of S. pumila seed loss to invertebrates was correlated with the sum of crickets (Gryllus pennsylvanicus) and beetles (Harpalus spp. and Ophonus rufibarbis) trapped during the 2011 season. During the same period, correlations between E. villosa seed loss to invertebrates and trapped insects were not observed. Reduced postdispersal seed predation by invertebrates could increase the local fall survival of the unburied seeds of invasive E. villosa populations, compared to other naturalized, smaller-seeded weedy grasses.

In the mid-1960s the founding of the Canadian Botanical Association provided a forum for the discussion of new botanical initiatives in Canada. At that time there was, coincidentally, a much increased interest in several areas of botany that had previously been little studied or ignored (e.g., plant autecology, plant population biology). As a result, many research projects became focused on individual species or small groups of closely related species. Botanists studying the native flora as well as those working with weed species became aware of the need for the compilation of all available information on important species, essentially in the format pioneered in Great Britain in the ‘‘Biological Flora of the British Isles’’. Botanists from the Central Experimental Farm in Ottawa (the Plant Research Institute) and the Botany Department at the University of Western Ontario in London decided to prepare a manuscript format for a Canadian version of the Biological Flora. Gerald Mulligan and Paul Cavers agreed to undertake this work. The initial plan was to ask the Editorial Board of the Canadian Journal of Botany to initiate a series with a tentative title ‘‘The Biological Flora of Canada’’. However, the Editor of the Canadian Journal of Botany did not accept this proposal. When we re-examined all the letters and other material received while the original proposal was being prepared, it was evident that by far the greatest support had come from scientists studying weeds and invasive plant species. In particular, many members of the Canada Weed Committee (later known as the Expert Committee on Weeds and currently as the Canadian Weed Science Society) enthusiastically recommended that this series be established. The Agricultural Institute of Canada, publishers of the Canadian Journal of Plant Science, agreed to publish the series under the title ‘‘The Biology of Canadian Weeds’’. We quickly revised the manuscript format to include aspects of weed biology not featured in the original proposal and published it in July 1972 (Cavers, P. B. and Mulligan, G. A. 1972. A new series The Biology of Canadian Weeds. Canadian Journal of Plant Science 52: 651 654). Gerry Mulligan was the first Editor of the series and Paul Cavers took the lead in finding authors and maintaining a list of Accounts in Preparation. The first account, published in October 1973, dealt with sheep-laurel (Kalmia angustifolia L.), a native species that is a weed of lowbush blueberry fields and pastures in eastern Canada. Since then, more than 150 accounts have been published, many on two or more species. In recent years, updates of several of the early accounts have been published. These updated accounts incorporate information on well-studied species published after the original account appeared. The series was popular from the outset, in fact there was such a great demand for many articles that the authors’ stocks of reprints soon were exhausted. In 1979, a book containing the first 32 accounts in the series was published by Agriculture Canada. Gerald Mulligan was the Editor and Compiler. In 1984, a second volume containing the next 29 accounts, with the same Editor/ Compiler and publisher, was printed. Volumes 3, 4 and 5 were published with Paul Cavers as the Editor/ Compiler by the Agricultural Institute of Canada in 1995, 2000 and 2005. In total, 129 original accounts plus three updated accounts were published in these five volumes (Table 1). In 2003, a new complimentary series was started, ‘‘The Biology of Invasive Alien Plants in Canada’’, in response to an expanding need for information on plants newly established or showing increased expansion in Canada, but for which there may be relatively little information available in a Canadian context. This series was intended to be similar in style and scope, but to concentrate on non-native plant species that have been more recently introduced into Canada than many of our common agricultural weeds, and for which there is substantial evidence that they may generate adverse economic impacts and management difficulties in agricultural systems or a broader landscape. The format for the Biology of Canadian Weeds has changed little over the years. Each contribution consists of 13 sections. The first section lists the currently accepted scientific name and the English and French vernacular names plus any synonyms that appear in the weed literature. The second section begins with a brief

Darbyshire, S. J., Francis, A., DiTommaso, A. and Clements, D. R. 2012. The Biology of Canadian weeds. 150 Erechtites hieraciifolius (L.) Raf. ex DC. Can. J. Plant Sci. 92: 729–746. Erechtites hieraciifolius, American burnweed, is a herbaceous annual in the Asteraceae native to forest zones of eastern North America, but introduced to parts of Europe and the Pacific region. Confusion sometimes arises in distinguishing it from other weedy rayless composites in Canada, such as Senecio vulgaris (common groundsel) and Conyza canadensis (Canada fleabane). A pioneer therophyte species of forest zones, it occurs in large numbers when associated with major disturbances such as forest fires, but is also common in areas of smaller scale disturbance such as shores, forest edges and wind-throws. Soil conditions may vary greatly in nutrient content, moisture content, pH and salinity. In Canada, it is generally considered a minor garden and agricultural weed. It is most common in crops such as lowbush blueberry (Vaccinium spp.), cranberry (Vaccinium macrocarpon), strawberry (Fragaria×ananassa) and vegetable crops; however, it occasionally occurs in other field and forage crops. Impacts include a variety of problems contributing to increased production costs or crop yield losses, including herbicide resistance, resource competition, and as a reservoir harbouring crop pathogens. It has been valued as a medicinal herb for treating a variety of ailments. Populations may grow rapidly in response to disturbances typical of managed landscapes, but E. hieraciifolius can usually be effectively controlled by chemical, cultural or manual weed control tactics.

Biodiversity is threatened by humankind's continuing usurpation of our planet's physical space and resources, and the associated damage to the landscape and atmosphere. Food production is widely ac...

Francis, A., Darbyshire, S. J., Clements, D. R. and DiTommaso, A. 2011. The Biology of Canadian Weeds. 146.Lapsana communis L. Can. J. Plant Sci. 91: 553–569. Nipplewort, Lapsana communis, is an annual weed of the Asteraceae native to Europe and western Asia, first detected in northeastern and Pacific northwestern regions of North America in the 19th century. It appears to have been introduced as a contaminant of imported garden material and seeds, but may also have been deliberately introduced as a medicinal herb. After a century of remaining close to its original points of introduction in gardens and ruderal habitats, it spread to neighbouring areas, and now occurs across southern Canada and in many areas of the United States. Possible reasons for this range expansion include forest clearance and changing crop management practices as was observed in Europe, where this plant has become an important weed in grain, forage and vegetable crops. In Ontario, L. communis has recently emerged as a weed in wheat ...

Darbyshire, S. J., Francis, A., Crompton, C. W. and Swanton, C. J. 2011. The Biology of Canadian Weeds. 145. Muhlenbergia frondosa (Poir.) Fernald. Can. J. Plant Sci. 91: 205–219. Muhlenbergia frondosa is a perennial grass native to eastern North America, which naturally inhabits moist to wet forest margins and openings, freshwater littoral habitats, and grasslands. In Canada, its spread as a weed appears to have coincided with changes in cultivation practices during the past few decades. Infestations in such crops as maize and soya bean have been reported mainly from southern Ontario and Quebec, and the Midwest and northeastern areas of the United States, where it reduces yields and can be difficult to control. It is shade tolerant and able to compete under the closed canopy of crops. Although this weed can be controlled by herbicides, its ability to spread by regrowth from rhizomes, and its abundant seed production, cause ongoing problems in arable fields, particularly in conservation-tillage systems. As a warm-season C4grass, growth begins relatively late in the season (early June in Canada), after most intensive weed control measures have already been taken. Timing herbicide application with active growth stages (10–30 cm) is most effective and the use of herbicide-tolerant crops provides additional control opportunities after crop planting.

Hemp dogbane, Apocynum cannabinum (Apocynaceae), is a perennial herb with white to greenish flowers in terminal clusters that produces pencil-like pods 12-20 cm long. A highly variable plant, A. cannabinum may be distinguished from spreading dogbane (Apocynum androsaemifolium) by its shorter corolla (2-6 mm compared with 5-10 mm), erect greenish-white petals (compared with recurved or spreading pinkish petals), seeds more than 3 mm long (compared with seeds less than 3 mm), and more erect leaves (compared with spreading or drooping leaves), although frequent hybridization between the two species obscures the identity of some individuals. Hemp dogbane is native to the United States and southern Canada, but most abundant in the upper Mississippi River Valley and east to the Atlantic coast. It has been increasing in other areas, and becoming more of a problem where conservation tillage is adopted. It infests crops such as corn (Zea mays), soybeans (Glycine max), wheat (Triticum aestivum), sorghum (Sorghum bicolor) and forages, and may cause livestock poisoning due to cardiac glycosides within its milky sap (but livestock generally avoid it). Potential medicinal uses of these compounds have been investigated, and the roots are a source of fibre. Control of A. cannabinum with various herbicides is difficult due to a thick cuticle, and one solution may be to target susceptible stages, such as seedlings or early spring growth. Cultivation may also control A. cannabinum, but care must be taken not to promote the proliferation of the plant through regrowth from fragmented roots and rhizomes. Rotation with alfalfa also reduces populations of A. cannabinum.Key words: Hemp dogbane, APCCA, Apocynum cannabinum, Apocynaceae, weed biology

Setaria faberi, commonly known as giant foxtail, is an annual graminaceous weed that is native to eastern China, has colonized eastern North America and is expanding its range westward. This species is primarily self-pollinated and the only mechanism of reproduction is by seed. Adult plants may reach 2 m in height and produce over 2000 seeds per panicle. Seeds may possess non-deep physiological dormancy when freshly produced, and can form small persistent seed banks. If not controlled, S. faberi populations can cause severe yield reductions in corn and soybean crops. Several herbicides are available to provide chemical control; however, resistance to some modes of action, (ALS, ACCase, and Photosystem II) have been identified in Canada and the United States. Leaves and seeds of this species provide a food source to several species of mammals, birds, and insects. Key words: Setaria faberi, giant foxtail, growth, development, seed germination, diseases, herbicide

The freshwater aquatic species Nymphoides peltata has been introduced to Canada as an ornamental plant and has been found at sites in Newfoundland, Nova Scotia, Quebec, Ontario and British Columbia. It is currently available through the aquatic nursery trade in Canada and the United States. It may be considered as adventive in Canada since populations readily expand beyond the site of planting, but there is no evidence as yet that it is fully naturalized. In the United States it has naturalized in still or slow-moving waters at widely scattered locations where it replaces native plant communities, changes ecological processes and interferes with human navigation and recreational activities. The short rhizomes over-winter under Canadian conditions, even when complete water drainage results in freezing of the substratum. In its native range, the species has two floral morphs (i.e., is distylous) with a weak incompatibility system, but North American populations usually consist of a single flower morph. A population at Ottawa, ON, has monomorphic flowers with characteristics overlapping between the two Eurasian morphs and has been observed to produce large numbers of viable seeds. Seeds germinate in the spring either on the substratum in shallow water or at the water surface. Seedlings germinating at the water surface may float for several weeks prior to sinking and establishing on the substratum in shallow water. Vigorous stolon production promotes rapid colonization, and vegetative dispersal is readily accomplished through fragmentation of stolons and stems. Key words: Nymphoides peltata, yellow floating-heart, Menyanthaceae, faux nénuphar, NYPPE, weed biology

Voucher specimens and herbarium collections provide the foundation for many aspects of research in the plant sciences. Available for study and verification by contemporary and future workers, voucher specimens promote reproducibility in scientific method because permanent records document identification, distribution, and interspecific and intraspecific variation of species. The utility and importance of voucher specimens and herbarium collections in supporting research in weed science are discussed, and the collection, preparation, documentation, storage, and shipment of voucher specimens are detailed.

The freshwater aquatic plant Cabomba caroliniana, or fanwort, was recently reported in a lake northeast of Peterborough, Ontario, where it has successfully established and survived winter conditions since at least 1991. This is the first documented occurrence of fanwort becoming naturalized in Canada. Fanwort is a popular aquarium plant that is native to South America and possibly the southeastern United States and has been introduced in several Asian, Pacific and European countries through the discarding or deliberate planting of aquarium plants in natural waterways. It is particularly invasive in China, Japan and Australia, and in parts of the United States, where its range is spreading. Fanwort grows rapidly and forms dense stands that clog waterways, impeding flow, obstructing navigation, altering fish habitat and excluding other vegetation. It does not produce mature seed in the northern parts of its North American range, but can multiply clonally and spread quickly by stem fragmentation. It produces turion-like stems at the end of the growing season, which assist in over-wintering under adverse conditions. Fanwort is difficult to control with herbicides and is resistant to mechanical management techniques as populations can quickly re-establish from plant fragments. Populations near the Trent-Severn Waterway in Canada are extensively established and management tools are not available to attempt eradication. An integrated management plan that focuses on early detection and rapid response in surrounding water bodies may succeed in mitigating the economic and environmental impacts and limiting the spread of fanwort. Key words: Cabomba caroliniana, fanwort, cabomba de Caroline, CABCA, aquatic plant, weed biology, invasive alien

Heracleum mantegazzianum (giant hogweed) is an invasive alien plant of management concern in southern Canada where it has escaped from horticulture and established and spread in natural, ruderal, and agricultural ecosystems. It poses a threat to natural ecosystems and human health, and is also a weed in agricultural and urban areas. It is a member of the Carrot family (Apiaceae) and is closely related to the native species Heracleum maximum Bartram (cow-parsnip). It is a monocarpic perennial, which generally flowers in its 3rd or 4th year. Large size, leaf shape, dark reddish pigments in patches on stems and petioles, and fruit characteristics readily distinguish H. mantegazzianum from other plants in Canada. It is increasingly common in riparian areas, floodplains, and forest edges in or near urban areas in southwestern British Columbia and southern Ontario. Based on herbarium specimens, H. mantegazzianum was first recorded in Ontario in 1949, British Columbia in 1964, Nova Scotia in 1980, Quebec in 1990, and New Brunswick in 2000. The development of dense stands of H. mantegazzianum can also reduce the richness of native plants. Contact with H. mantegazzianum can cause phytophotodermatitis, a serious skin inflammation caused by UV photo-activation of furanocoumarins present in the sap. Control methods include herbicide application, mechanical cutting, and animal grazing, but strategies to address seed dispersal and re-establishment from dormant seed must also be adopted. Widespread establishment in southern Canada suggests that eradication is unlikely. However, range expansion and rapid population growth can be prevented through strategic management including public education. Key words: Giant hogweed, Heracleum mantegazzianum, Apiaceae, HERMZ, invasive plant, weed biology, furanocoumarins

Cynanchum rossicum (dog-strangling vine) and C. louiseae (black dog-strangling vine) are introduced, perennial herbs or small twining vines in the Milkweed family (Asclepiadaceae). Generic placement of these two species has been problematic, but are here treated as members of Cynanchum subgenus Vincetoxicum. The species occur primarily in natural upland areas, including understories of woodlands, pastures, old fields, shores, flood plains and ruderal areas of southern Ontario and Quebec and the northeastern United States. Ecosystems on well-drained, stony soils are often densely colonized, but both species can tolerate a wide moisture regime. Plants establish in full sun or under forest canopies and may form monospecific stands in all light conditions. They often form dense colonies which smother other vegetation and reduce invertebrate and vertebrate biodiversity. Reproduction is by polyembryonic, wind-dispersed seeds. Effective control is primarily by herbicides, since mechanical control is difficult and no biological control agents have been developed. A third European species, C. vincetoxicum, has been reported as an occasional garden escape in southern Ontario and the northeastern United States, but has not yet become naturalized. Information on this species is included because of its close relationship with C. rossicum and its better known biology. Key words: Dog-strangling vine, swallow-wort, Cynanchum, Vincetoxicum, CYKNI, invasive plant, weed biology

Panicum capillare L., witch grass, is an annual grass native to North America that infests field crops, small grains, grasslands, and a variety of other habitats. High seed production, a persistent seed bank, a tumble-weed seed-dispersing mechanism, and the ability to tolerate some herbicides contribute to the success of P. capillare in these habitats. Despite the widespread presence of P. capillare in crops, its actual impact on crop yield is not well documented. It is an additional host for several insect pests (e.g., cereal aphids) and diseases attacking crop species. Key words: Panicum capillare, witch grass, panic capillaire, weed biology, native weed species

Wild chervil, Anthriscus sylvestris (L.) Hoffm. (Apiaceae), is a weed of perennial crops, old fields, disturbed areas and roadsides. Introduced from Eurasia, it is widely naturalized in eastern Canada from Newfoundland to Ontario and at two sites in British Columbia. It is a monocarpic short-lived perennial, reproducing by seed and budding from the root crown. Dense populations achieved through vegetative reproduction can exclude most other vegetation. The rust, Puccinia pimpinellae subsp. pimpinellae, was detected on a population of wild chervil from Quebec. Key words: Wild chervil, Anthriscus sylvestris, weed biology

Summary Types of names of seven taxa described by Steudel in his Synopsis plantarum glumacearum from the Labrador collections of the Moravian missionary Albrecht were examined. Information com- piled from the specimen labels as well as biographic and bibliographic sources suggest this material was collected at Hopedale between 1846 and 1848. Samples of the handwriting of Albrecht, Steudel, and possibly Hohenacker are presented. Reinterpretation of the types is pro- vided and a lectotype of Calamagrostis hirtigluma is designated. Biographical information on C. G. Albrecht, as well as several poorly known Moravian missionaries, is presented.

The new nothogenus ×Dupoa (Dupontia × Poa) is published. Nomenclature of the only known nothospecies, ×Dupoa labradorica (=Poa labradorica), is discussed. Morphology and synecology of this poorly known arctic and subarctic grass are described and a key to related taxa is given. Its morphology and ecology overlap with the putative parental taxa, Poa eminens and Dupontia fisheri ssp. psilosantha. Establishment and persistence of this sterile hybrid are related primarily to geological processes associated with glacio-eustatic rebound and seasonal ice action affecting its seashore habitats.

The name x Dupontopoa was proposed by Probatova (in Probatova & Jurcev, 1984) to accommodate hybrids between the genera Dupontia R. Br. and Arctopoa (Griseb.) Prob. (= Glyceria sect. Arctopoa Griseb. in Ledebour, Fl. Ross. 4: 392. 1852; = Poa sect. Arctopoa (Griseb.) Tsvelev, Arkt. Fl. SSSR 2: 121. 1964; = Poa subg. Arctopoa (Griseb.) Prob., Novosti Sist. Vyss. Rast. 11: 49. 1974). A single nothospecies, xDupontopoa dezhnevii Prob., from the Chukchi Peninsula of eastern Russia, was described and named as a cross between Arctopoa eminens (J. S. Presl) Prob. and Dupontia psilosantha Rupr. Poa labradorica Steudel, described from North America, has been identified as the hybrid product of the latter taxa using phytogeographical, morphological, anatomical, cytological, isozyme and DNA data (Darbyshire & al., 1992). The type of xDupontopoa dezhnevii was examined and compared with types of P labradorica in morphology and anatomy. The nomenclatural problems of P labradorica will be dealt with elsewhere.

Forty-three vascular plant specimens were found recently at the National Herbarium of Canada that were collected by Sir Joseph Banks on his voyage to Newfoundland and Labrador in 1766. A list of these specimens is presented together with a discussion of the relationship that they bear to collections at the British Museum (Natural History) in London as well as information contained in Banks's personal diary and plant catalogue.

A series of collections from Guadalupe y Calvo in southern Chihuahua State, Mexico, is described as a new species, Festuca diclina (Poaceae), and compared with similar species from Central America. Festuca diclina S. J. Darbyshire, sp. nov. TYPE: Mexico. Chihuahua: Mpio. Guadalupe y Calvo, Cerro de Mohinora, S de Guadalupe y Calvo, 3300 m, alpina-subalpina, en ladera rocosa, 27 Aug. 1987, McDonald & Martinez 2392 (holotype, DAO 661232; isotypes, TEX (ex DAO 591464), MEXU (ex DAO 592610)). Figure 1. Plantae perennes caespitosae, innovationibus intravaginalibus praeditae. Vaginae foliorum ima basi tantum integrae, vertice scabrae; ligulae 0.2-0.5 mm longae; laminae foliorum plicatae vel convolutae, 1.2-1.5 mm latae, abaxialiter ima basi scabrae, adaxialiter sparsim scabrae, 5-7-costatae, fasciculis sclerenchymaticis cum nervis infra et saepe supra conjunctis, non confluentibus. Culmi 30-75 cm longi, glabri. Paniculae 8-15 cm longae, plus minusve laxae, pyramidales, axe et ramulis glabris vel trichomatibus sparsis, ramulis interdum tortuosis. Spiculae 8-12 mm longae, (2-)3-4(-5) flosculis; glumae inferiores 2.4-4 mm longae, 1-nerviae; glumae superiores 3.5-5 mm longae, (1-)3-nerviae; rachillae trichomatibus 0.1-0.3 mm longae praeditae; lemmata lanceolata, glabra vel apice scabra, 1-3(-5)-nervia, 6-8 mm longa, interdum arista ad 1.0 mm longa; paleae 5.5-7 mm longae, bidentatae, apice piloso-hirsutae inter nervos, nervis cum trichomatibus 0.1-0.2 mm longis prope apicem; antherae interdum abortivae praesertim flosculis inferioribus, 34.2 mm longae; ovariorum apex dense pubescens. Caespitose, loosely tufted perennial (Fig. 1A); shoots intravaginal. Vegetative shoots to 25 cm tall, light green (not glaucous); sheaths rapidly decaying to fibers, the margins closed only at the base, the upper parts of the sheaths, collars, and lower abaxial blade surface retrorsely scabrous; auricles absent; ligules short, 0.2-0.5 mm long, acute to truncate, sometimes lacerate, puberulent apically and abaxially, membranous; blades plicate to convolute, adaxially sparsely scabrous, 1.2-1.5 mm wide on flattened blades (about 0.4-0.8 mm in the longest dimension of a cross section), with 7(-9) veins and 5-7 adaxial ribs; sclerenchyma in discrete fascicles opposite veins abaxially and usually adaxially (Fig. 2A-C), the fascicles usually joining veins abaxially and sometimes adaxially thus forming a girder between the epidermises through the veins (Fig. 2A). Culms 30-75 cm tall, glabrous; nodes black or brown, glabrous. Flag leaf sheath sometimes loose. Panicle open, pyramidal, 8-15 cm long; rachis glabrous below and sparsely scabrous on the angles above; branches + flexuous and sometimes sinuously undulating, 1 or 2 per node, glabrous or sparsely scabrous, the lowest 5-9 cm long. Spikelets 8-12 mm long, distal on the branches, with (2-)3-4(-5) florets; glumes chartaceous, glabrous or scabrous on the keel (especially apically), ovate-lanceolate to lanceolate with wide hyaline margins; lower glume 2.44 mm long, 1-nerved; upper glume 3.5-5 mm long, (1-)3-nerved; rachilla with hairs 0.1-0.3 mm long (Fig. 1C); lemmas 6-8 mm long, narrowly lanceolate (Fig. 1B), glabrous or scabrous-hirsute apically, 13(-5)-nerved (the lateral ones faint), the apex attenuate, sometimes with a terminal awn or mucro to 1.0 mm long; paleas subequal to the lemmas, 5.5-7 mm long, bidentate, apically pilose-hirsute between the nerves and with hairs 0.1-0.2 mm long on the nerves (Fig. 1 D, E); anthers sometimes abortive especially in lower florets, 3-4.2 mm long when developed; ovary apex densely pubescent (Fig. 1F); styles 2. Caryopses not seen. Specimen label data from the type collection describe the culms as up to 2 m high, although all specimens examined were much less. Distribution. Collections of Festuca diclina are known only from the vicinity of Guadalupe y Calvo, Sierra Madre Occidental, Mexico, in montane pine forests at altitudes of 2950-3300 m. Festuca diclina belongs to Festuca subg. Festuca and is similar to F. hintoniana E. B. Alexeev (Figs. 1G-K, 2D) but differs primarily in the loose tufts with non-persistent sheaths decaying to separate fibers (densely tufted with persistent chartaceous sheaths in F. hintoniana), scabrous upper sheaths, collars, and lower leaf blades (not glabrous), narrower leaf blades (1.6-1.9 mm on flattened blades and 0.7-1.0 mm in longest dimension of transverse section in F. hintoniana), blade sclerenchyma in discrete fascicles (more or less continuous abaxial NovoN 5: 129-132. 1995. This content downloaded from 207.46.13.168 on Sat, 09 Apr 2016 06:53:20 UTC All use subject to http://about.jstor.org/terms

Evidence from the literature of the close relationship of Festuca subg. Schedonorus to Lolium and its relatively distant relationship to Festuca subg. Festuca is briefly discussed. New combinations, Lolium subg. Schedonorus, Lolium arundinaceum, Lolium giganteum, Lolium mazzettianum, and Lolium pratense, are proposed to reconcile classification with known phylogeny. The relationship between Festuca L. and Lolium L. (Poaceae) has long been an interesting classification problem. Lolium is readily distinguished from Festuca by its spicate inflorescence and lateral spikelets with a single glume. This morphology suggests the spikelike inflorescence structure in the tribe Triticeae Dumortier, where Lolium, in early treatments, was often placed. Nevski (1934) was the first to place Lolium in the Poeae (= Festuceae) rather than the Triticeae. Information from diverse nonmorphological sources, such as hybridization and cytology (e.g., Jenkin, 1959), oligosaccharides and water-soluble polysaccharides in caryopses (MacLeod & McCorquodale, 1958), endosperm structure (Tateoka, 1962), seed protein electrophoresis (Bulinska-Rodomska & Lester, 1988; Butkute & Konarev, 1982), serology (Butkute & Konarev, 1980, 1982; Fairbrothers & Johnson, 1961; Smith, 1969; Watson & Knox, 1976), chloroplast DNA (cpDNA) restriction endonuclease site patterns (Lehvaslaiho et al., 1987; Soreng et al., 1990), cpDNA reassociation (Hilu & Johnson, 1991), and thermal denaturation of genomic DNA (King & Ingrouille, 1987), has supported the placement of Lolium in Poeae. Spontaneous hybridization occurs commonly between species of Festuca subg. Schedonorus (P. Beauvois) Petermann and chasmogamous species of Lolium, particularly the type species of the genus, L. perenne L. (Barker & Stace, 1986; Humphries, 1980; Gymer & Whittington, 1973). Hybridization between Lolium and Festuca subg. Festuca rarely occurs spontaneously and is reported only for Festuca rubra L. (Stace, 1975). The latter is, however, also reported to hybridize with species in Festuca subgenera Festuca and Schedonorus as well as Vulpia C. C. Gmelin (Ainscough et al., 1986; Knobloch, 1968; Saint-Yves 1929; Stace, 1975). Hybridization between Festuca (Schedonorus) pratensis Hudson and Lolium perenne (= x Festulolium loliaceum (Hudson) P. V. Fournier) was suspected as early as 1790 (see Jenkin, 1933). Reproductive barriers are not appreciably greater for this hybridization than for interspecific hybridization within Festuca subg. Schedonorus or between many species of Lolium (Jenkin, 1933; Stace, 1975). The degree of difficulty in producing artificial L. perenne x F. pratensis hybrids and the differential success of reciprocal crosses is similar to interspecific hybridization reported in various plant genera (e.g., Borrill et al., 1977; Gymer & Whittington, 1973). Extensive studies of artificial hybrids and their chromosome behavior (for references, see Jauhar, 1974, 1975; Terrell, 1966), as well as chromosome banding (Dawe, 1989; Thomas, 1981), have indicated the homology of chromosomes and their genetic compatibility. In auto-allotriploids and amphidiploids of L. perenne, L. multifiorum L., and F. pratensis, synapsis of homeologous chromosomes usually occurs as multivalents or even bivalents, in spite of the presence of true homologues (Jauhar, 1974, 1975). Diploid crosses of these taxa show high bivalent formation (87-100%) with 0.783-0.896 chiasmata per chromosome pair (Jauhar, 1975). Such observations have led many taxonomists and cytogeneticists to suggest that Festuca and Lolium could be combined, in whole (e.g., Jauhar, 1975; Knobloch, 1963; Love, 1963; Stebbins, 1956; Terrell, 1966; Ullmann, 1936) or in part (e.g., Tutin, 1956). Amalgamation of Festuca and Lolium has been proposed as early as 1898 (M'Alpine, 1898), but no valid combinations of Festuca subg. Schedonorus taxa within Lolium are available. Raspail (1829), however, included F. pratensis (under the name F. elatior L.) and F. loliaceum Hudson (= F. pratensis x L. perenne) in his examination of Lolium as L. festuca Raspail and L. festucoides Raspail, respectively. Proposed on the basis of morphological and ecological continua observed between these taxa and NOVON 3: 239-243. 1993. This content downloaded from 157.55.39.147 on Wed, 21 Sep 2016 05:43:37 UTC All use subject to http://about.jstor.org/terms