Phlox longifolia Nutt. (Polemoniaceae) complex of North America

Over 1,000 herbarium specimens including 24 type specimens were examined in an attempt to achieve a clearer understanding of the Phlox longifolia complex. Four variables were measured for each specimen and the data were statistically analyzed by discriminant analysis. Using a previously published system of classification for the complex, approximately 73 percent of the measured variation among the specimens was accounted for by that system. The clustering patterns produced in this first analysis indicated that a more conservative approach would be advisable. The formulation and subsequent application of a modified system produced a grouping of specimens that accounted for 95 percent of the measured variation for the four morphological characters considered. From four species and seven subspecies previously recognized, one species with five varieties is proposed. The typification of Phlox longifolia Nutt. and other related taxa is resolved.        

Typification and nomenclature of Hedysarum boreale Nutt. (Leguminosae)

The holotype of Hedysarum boreale Nutt. is convarietal with natural populations now known as Hedysarum boreale Nutt. var. cinerascens (Rydb.) Rollins instead of var. boreale. The new combination Hedysarum boreale Nutt. var. rivulare (Williams) Northstrom is proposed for populations formerly known as var. boreale.     

The genus Eriogonum Michx. (Polygonaceae) and Michel Gandoger

New species and varieties of the plant genus Eriogonum (Polygonaceae) that occur in Nevada are proposed. Eriogonum tiehmii and E. ochrocephalum var. alexanderae are endemic to Nevada, and E. lewisii is restricted to extreme northeastern Nevada and adjacent Utah. These entities belong to the subgenus Eucycla. Two varieties of E. umbellatum (of the subgenus Oligogonum) are proposed. The first, var. juniporinum , is found in eastern Nevada and in the desert ranges of southeastern California. The second is var. furcosum , which is restricted to the Sierra Nevada. One new combination is also proposed: E. nudum var. gramineum .         

Types of Nevada buckwheats ( Eriogonum: Polygonaceae)

The types and type specimens of Nevada species and varieties of Eriogonum  (Polygonaceae) are alphabetically listed. Appropriate lectotypes are selected as necessary.         

A revision of Eriogonum (Polygonaceae) subgenus Pterogonum

This revision discusses the 10 species of Eriogonum assigned to the subgenus Pterogonum. Six of the species are essentially restricted to northern Mexico; two additional species, E. hemipterum and E. nealleyi, are found primarily in Texas; and the remaining two, E. hieracifolium and E. alatum, are the most widespread species of the subgenus being found mainly in the United States and just barely entering Mexico. The subgenus is characterized by the broad, often winged or ribbed achenes, and the generally erect habit of the stems of these perennial herbs. Three new species, E. fimbriatum, E. viscanum, and E. clivosum, are described. They are related to E. ciliatum and are found in the desert foothills of north central Mexico. Two new varieties of E. atrorubens are proposed. One, var. nemorosum, is restricted to the high mountains of the Sierra Madre Occidental in northern Durango and southern Chihuahua, while the second, var. auritulum, is a plant of the Sierra Madre Oriental of Coahuila and Nuevo León. The subgenus is divided into four sections, two of which, Peregrina and Astra, are new. Cytological information is given for nearly all taxa and shows the majority of species to have a haploid number of 20. Eriogonum atrorubens var. intonsum is a polyploid with n = 40, and E. greggii is the most unusual with a haploid number of 16. Each species is described in detail, discussed, and illustrated. Distribution maps are given noting the known locations for each taxon.     

Annotated key to Eriogonum (Polygonaceae) of Nevada

Seventy - three species of Eriogonum (Polygonaceae) are reported for Nevada. A key is provided for the identification of these species along with brief notes on their distribution in the state and elsewhere.         

A new pulvinate Eriogonum (Polygonaceae) from Utah

A new species of pulvinate wild buckwheat, Eriogonum soredium (Polygonaceae, Eriogonoideae) is described from near-barren limestone slopes in the Grampian Hill area near Frisco, Beaver County, Utah. The new species is outwardly similar to E. shockleyi S. Wats, but may be readily distinguished by its glabrous (not pubescent) flowers and fruits, generally smaller leaves, more numerous involucres per head, turbinate (not campanulate) involucres with 5, rarely 4 (not 5 to 10) teeth, and the smaller flowers.     

New Nevada entities and combinations in Eriogonum (Polygonaceae)

New species and varieties of the plant genus Eriogonum (Polygonaceae) that occur in Nevada are proposed. Eriogonum tiehmii and E. ochrocephalum var. alexanderae are endemic to Nevada, and E. lewisii is restricted to extreme northeastern Nevada and adjacent Utah. These entities belong to the subgenus Eucycla. Two varieties of E. umbellatum (of the subgenus Oligogonum) are proposed. The first, var. juniporinum , is found in eastern Nevada and in the desert ranges of southeastern California. The second is var. furcosum , which is restricted to the Sierra Nevada. One new combination is also proposed: E. nudum var. gramineum .         

Two new varieties of Eriogonum (Polygonaceae) from the intermountain region

The types and type specimens of Nevada species and varieties of Eriogonum  (Polygonaceae) are alphabetically listed. Appropriate lectotypes are selected as necessary.         

Identity of Mertensia oblongifolia (Nutt.) G. Don (Boraginaceae) and its allies in western North America

The current status of Mertensia oblongifolia (Nutt.) G. Don and its allied taxa is surveyed. On the bases of continuously coherent morphological characters and/or regionally correlated variations, more than 30 taxa, including species, subspecies, varieties, and 1 forma, previously considered different from M. oblongifolia , are now placed under synonymy of this species. Those taxa currently known as M. fusiformis Greene, M. bakeri Greene, and M. bakeri var. osterhoutii Williams are among the new synonyms. Typification, taxonomy, and morphological problems of M. oblongifolia are discussed.     

Genetic differentiation of rare and common varieties of Eriogonum shockleyi (Polygonaceae) in Idaho using ISSR variability

Idaho populations of Eriogonum shockleyi are divided taxonomically into 2 varieties: E. shockleyi var. packardae , which is endemic to Idaho, and the typical variety, which is widespread in the western United States. Recent morphological investigations of E. shockleyi in Idaho have identified potentially reliable morphological characters for field identification of the subspecific taxa. This paper investigates the genetic basis for the separation of the 2 varieties of E. shockleyi using inter simple-sequence repeats (ISSR) markers. Although we found some morphological differences between the populations that correlated with the 2 varieties, we identified no molecular markers in this study to distinguish between them. Morphological measurements obtained in the field indicate that although a population may have an overall average morphology that defines the variety, some individuals in nearly all populations have putative diagnostic characters that define the other variety. The morphological characters used to distinguish the 2 varieties are most likely the result of environmental variability and could result from differences in precipitation and soil water retention. Alternatively, high levels of outcrossing through pollen flow could be obscuring selection for morphological characters at particular sites.     

Eriogonum divaricatum Hook (Polygonaceae), an intermountain species in Argentina

Erogonum divaricatum, an annual herb of clay slopes and flats in the Green and Colorado river drainage basin of the western United States, was found at the turn of the century in three locations in southern Argentina. The South American material was described in 1902 as a new species of Erogonum, E. ameghinoi Speg., and this name was the basionym for a new monotypic genus, Sanmartinia M. Buchinger, proposed in 1950. The species has not been rediscovered in Argentina, and the presence of the species in South America was probably the result of a long-distance dispersal event involving shore birds.     

Development and longevity of ephemeral and perennial leaves on Artemisia tridentata Nutt. ssp. wyomingensis

Big sagebrush ( Artemisia tridentata Nutt.) is one of the most successful plants in the Great Basin based on its abundance and wide distribution. The development of dimorphic leaves may be an important mechanism attributing to its adaptive and competitive abilities. Development, persistence, and proportions of ephemeral and perennial leaves on Wyoming big sagebrush ( Artemisia tridentata Nutt. ssp. wyomingensis ) were studied for two years. The large ephemeral leaves are the first to develop in early spring. As early developing ephemerals mature and stems elongate, new ephemeral and perennial leaves develop in the axes of these large ephemerals. Perennial leaves expanded in the summer of their first growing season, persisting on the shrub until their abscission during summer drought of the second growing season. Plants maintained 33% of their leaf weight through the winters of 1985 and 1986. Active leaf and stem growth occurred at soil water potentials above –0.2 MPa.     

On the taxonomic status of Eriogonum robustum (Polygonaceae), a rare endemic in western Nevada

Evidence from the morphology, genetics, and biogeography of a rare endemic from western Nevada, Erigonum robustum , is presented to determine the most accurate taxonomic classification. Previous authors have classified E. robustrum Greene both as a species and as a variety E. lobbii Torrey & Gray. However, results of a morphometric comparison for 9 characters establish that significant morphological differentiation exists between E. robustum and E. lobbii . In addition, results of a genetic study using protein electrophoresis indicated that genetic differentiation may exist between these 2 taxa. Furthermore, the 2 taxa are geographically, ecologically, and reproductively isolated. Finally, the selective pressures that act on E. robustum in a narrowly restricted cold-desert environment are different from those that act on E. lobbii in subalpine environment. Thus, all available data support a species-level taxonomic classification for E. robustum .     

Ecological relationships of curlleaf mountain-mahogany ( Cercocarpus ledifolius Nutt.) communities in Utah and implications for management

Curlleaf mountain-mahogany is a widely distributed shrubby tree of western North America. Well-developed stands are most often found on warm, dry, rocky ridges and slopes at high elevations on mostly southern exposures. It can, however, be found onall exposures. The species appears to be indifferent to substrate with soils which are invariably shallow and of low fertility. However, the nitrogen-fixing root nodules help overcome soil deficiencies. This highly palatable species is preferred by mountain sheep, mountain goats, deer, and elk. Its nutritive value (about 12% protein) and digestibility ratings (around 50%) in the winter are high when compared with most other associated winter browse species. Early research with curlleaf mountain-mahogany basically dealt with two major management problems: (1) how to increase available forage production on old, even-aged stands too tall for big game to browse, and (2) how to increase reproduction in these same communities. Selective dozer thinning, sometimes in conjunction with the seeding of fast-growing plants, appears to be a promising management technique providing browse until the younger curlleaf becomes established.     

Nutrient relationships between Orobanche fasciculata Nutt. and its host Artemisia pygmaea Gray in the Uinta Basin of Utah, USA

Patterns of mineral nutrient uptake and distribution within the roots, stems, and leaves of Artemisia pygmaea and in the vascular parasite Orobanche fasciculata were investigated. All nutrients studied were magnified over concentrations found in the soil into the host and parasite. Nitrogen, phosphorus, potassium, and zinc were magnified along the flow gradient of soil-roots-stems-leaves of the host. All others increased in the roots and then decreased in the stems and leaves. Orobanche fasciculata concentrated phosphorus, potassium, and sodium over soil and root concentrations while excluding to some degree all others.