Plant Sciences Commons^™

The Fascinating History Of The Early Botanical Exploration And Investigations In Southern California, Mildred E. Mathias

Aliso: A Journal of Systematic and Floristic Botany

Information on plant collectors in southern California is scattered through a number of publications, some of them obscure or not well known to botanists. This paper gives a selective account of major collectors from 1793 to 1930. The appendix lists the plant collectors with references to biographical material concerning each. It is hoped that this preliminary account will stimulate further historical studies.

Wood And Bark Anatomy Of The New World Species Of Ephedra, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Quantitative and qualitative data are presented for wood of 42 collections of 23 species of Ephedra from North and South America; data on bark anatomy are offered for most of these. For five collections, root as well as stem wood is analyzed, and for two collections, anatomy of horizontal underground stems is compared to that of upright stems. Vessel diameter, vessel element length, fiber-tracheid length, and tracheid length increase with age. Vessels and tracheids bear helical thickenings in 10 North American species (first report); thickenings are absent in Mexican and South American species. Mean total area of perforations per mm …

Wood And Bark Anatomy Of Degeneria, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Wood anatomy of the recently described Degeneria roseiflora differs from that of D. vitiensis by possessing narrower vessels, much thicker-walled vessels and fiber-tracheids, abundant uniseriate rays, and greater numbers of ethereal oil cells in rays. Because both large and smaller wood samples of D. vitiensis were studied, ontogenetic changes in the wood are presented and separated from those features that probably vary with the species. Tyloses and perforated ray cells are newly reported for Degeneria. Anatomy of mature bark of D. roseiflora is described. Wood anatomy of Degeneria is moderately primitive. Although Degeneria is often compared to Himantandraceae and …

New Species Of Scutellaria (Lamiaceae) From The Chihuahuan Desert Region, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

Three new species of Scutellaria are described from the Chihuahuan Desert Region of Mexico: S. hintoniorum from western Nuevo León, S. wendtii from eastern Chihuahua, and S. carmenensis from northern Coahuila.

Wood And Bark Anatomy Of Empetraceae; Comments On Paedomorphosis In Woods Of Certain Small Shrubs, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Wood and bark of 12 collections of Empetraceae representing three genera containing seven species (one with two subspecies) are analyzed with respect to quantitative and qualitative features. Empetraceae have vessels somewhat angular in transection, with scalariform perforation plates and scalariform to opposite vessel-ray pitting. Imperforate tracheary elements are all tracheids. Axial parenchyma is sparse and not subdivided. Rays are characteristically uniseriate and composed of upright cells (older stems have rays with both upright and procumbent cells). These features ally Empetraceae closely to Ericaceae and Epacridaceae. The narrow vessels, quite numerous per mm² , denote a high degree of wood …

Relationships Among Wood Variables In Two Species Of Ring-Porous Trees, D. W. Woodcock

Aliso: A Journal of Systematic and Floristic Botany

One way of assessing the functional significance of wood-anatomical variables is by examining the relationships among these variables. This paper presents results of factor analysis of wood variables in two species of ring-porous trees (Quercus rubra and Fraxinus americana). Factor analysis of vessel diameter and density, conductive area, and conductivity in the early- and latewood plus width of the early- and Iatewood increment reveals from three to four independent sources of variance. Generally, these can be characterized as diameter-related factors in the early- and latewood, tentatively related to water conduction, and a factor identified with width of the …

Steps Toward The Natural System Of The Dicotyledons, William C. Dickison

Aliso: A Journal of Systematic and Floristic Botany

The value of vegetative anatomy in phylogenetic analysis is documented. Examples of the use of vegetative anatomy at different taxonomic levels show the continuing role of the anatomical method in building a more natural system of classification of the dicotyledons. The importance of correlating wood and leaf anatomical features with ecological and floristic preferences of taxa is emphasized. Caution is required in basing phylogenetic interpretations upon similarities and differences in xylem structure. The transition from scalariform to simple perforation plates is the only aspect of vessel element evolution that is not potentially reversible and all phylogenetic analyses must reflect this …

A New Scandent Species Of Bidens (Asteraceae) From The Balisas River Basin, Mexico, Jose Luis Villaseñor

Aliso: A Journal of Systematic and Floristic Botany

Bidens esmartinezii from the Balsas River Basin, Michoacan and Guerrero, Mexico, differs from B. reptans var. urbanii and B. squarrosa, the only other climbing species occurring in the area, by its entire, mostly linear leaf lobes and its larger, brown achenes.

Stem And Leaf Anatomy Of The Alseuosmiaceae, William C. Dickison

Aliso: A Journal of Systematic and Floristic Botany

The stem and leaf anatomy of five species representing all three genera of the small Southwest Pacific dicotyledonous family, Alseuosmiaceae, were studied. Salient anatomical features common to all genera include: a trilacunar, three-trace leaf-node structure in which petioles are supplied with three separate vascular bundles; rosoid teeth bearing hydathodes; anomocytic stomata; unicellular, bicellular, and multicellular, unbranched, living trichomes; a superficial origin of periderm; leafmesophyll composed of a uniseriate palisade region and a loosely constructed spongy zone; and the presence of a stem and foliar endodermis. Sclerenchyma occurs in stem tissues of species belonging to all three genera and Crispiloba disperma …

A Monograph Of Sabal (Arecaceae: Coryphoideae), Scott Zona

Aliso: A Journal of Systematic and Floristic Botany

This monographic study of the New World genus Sabal (Arecaceae: Coryphoideae) recognizes 15 species. In addition to defining species limits and distributions, the study addresses broader questions concerning likely modes of speciation in the group and biogeographic radiation. The systematic treatment incorporates results from extensive field work and studies of leaf anatomy and flavonoid phytochemistry, ecology and biogeography, and morphology. Distribution maps and a key to the taxa are provided. Solutions are offered for the many nomenclatural problems that existed in the genus. A phylogenetic hypothesis, the first for the genus, is proposed. Moreover, phytochemical and anatomical features are examined …

The Genera Of Asteraceae Endemic To Mexico And Adjacent Regions, Jose Luis Villaseñor

Aliso: A Journal of Systematic and Floristic Botany

The flora of Mexico includes about 119 endemic or nearly endemic genera of Asteraceae. In this study, the genera are listed and their distribution patterns among the floristic provinces of Mexico analyzed. Results indicate strong affinities of the endemic genera for mountainous and arid or semiarid regions. Since its first appearance in Mexico, the Asteraceae diversified into these kinds of habitats, which were produced mostly by recurrent orogenic and climatic phenomena. The specialized tribes Heliantheae and Eupatorieae are richly represented, a fact that places Mexico as an important secondary center of diversification for the Asteraceae.

Dudleya Cymosa Subsp. Costafolia (Crassulaceae), A New Subspecies From The Southern Sierra Nevada, Tulare County, California, Jim A. Bartel, James R. Shevock

Aliso: A Journal of Systematic and Floristic Botany

Dudleya cymosa subsp. costafolia, a new subspecies from the southern Sierra Nevada, Tulare County, California, is described and illustrated. Along with bright yellow flowers, the cespitose plant produces numerous, small rosettes with rib-shaped linear to linear-oblanceolate leaves, which are unique to the subspecies. The authors have searched numerous other rock outcrops, especially limestone, in the general area for additional plants with no success. Dudleya cymosa subsp. costafolia evidently is restricted to a solitary limestone outcrop north of the South Fork of the Middle Fork of the Tule River.

Monardella Stebbinsii (Lamiaceae), A New Serpentine Endemic Species From The Northern Sierra Nevada, Plumas County, California, Clare B. Hardham, Jim A. Bartel

Aliso: A Journal of Systematic and Floristic Botany

Monardella stebbinsii (Lamiaceae ), a new species from the northern Sierra Nevada of Plumas County, California, is described and illustrated. Characterized by ovate leaves, multiple verticillasters per infiorascence, a matlike habit, reddish papery bracts, and purplish-red leaves with a soft white pubescence, the species is not closely related to any other species of the genus. The new species is apparently restricted to the central portion of a serpentine outcrop located north and east of the confluence of the North Fork of the Feather River and its East Branch.

Protecting The Remnants, Glenis Ayling

Journal of the Department of Agriculture, Western Australia, Series 4

Our native flora and fauna do best in their own environment, so one way of protecting them is to conserve and maintain areas of remnant vegetation throughout our farmlands. This is the aim of the Remnant Vegetation Protection Scheme in which the State Government helps private landholders to voluntarily fence off and manage areas of native vegetation on farms.

Seed Phosphorus : Its Effect On Plant Production, Mike Bolland, Mike Riley, Brett Thomson, Blakely Paynter, Mike Baker

Journal of the Department of Agriculture, Western Australia, Series 4

The amount of phosphorus in the seed of annual crop and pasture species influences production of plants grown from that seed. It appears the more phosphorus there is in the seed, the better the potential yield irrespective of whether fertilizer phosphorus is applied to the soil or not. This article discusses the influence of phosphorus concentration in the seed of annual crop and pasture species on subsequent production. It also explains the difference between phosphorus concentration and phosphorus content in the seed

Coping With Brown Spot And Root Rots Of Lupins, Mark Sweetingham

Journal of the Department of Agriculture, Western Australia, Series 4

There is increasing concern that brown spot and root diseases may limit the long term viability of lupin cultivation in close rotations in the agricultural areas of Western Australia. Research has found several useful strategies to reduce the impact of brown spot and Pleiochaeta root rot so that losses can be kept to a minimum. Rhizoctonia has proved more difficult to combat. Although less widespread than Pleiochaeta, it has caused severe losses and appears to be increasing in incidence, particularly in the northern wheatbelt. Research has vastly expanded our knowledge of the strains of Rhizoctonia present in our soils and …

Phosphorus Retention Of Sandy Horticultural Soils On The Swan Coastal Plain, Ian Mcpharlin, Neil Delroy, Bob Jeffery, Greg Dellar, Maurice Eales

Journal of the Department of Agriculture, Western Australia, Series 4

Soils can be ranked according to their phosphorus retention capacity by the phosphorus retention index (PRI). This is the ratio of phosphorus adsorbed by soil to that remaining in solution under a set of standard conditions. Although it is a laboratory measurement, the PRI seems to be a good indication of what happens in practice.

Monitoring Western Australia's Rangelands, Ron Hacker, David Beurle, George Gardiner

Journal of the Department of Agriculture, Western Australia, Series 4

Rangelands, native pastures used for grazing domestic livestock, occupy about 100 million hectares or 40 per cent of Western Australia, extending from the tropical grasslands of the Kimberley to the arid shrub steppe of the Nullarbor Plain.

The rangelands are characterized by highly variable seasonal conditions. Carrying capacity can fluctuate dramatically from year to year. Grazing management requires a tactical approach from one season to the next because of the great variation in the capacity of the land to support stock.

Rangeland monitoring provides pastoralists with objective information on these changes to assist their management decision making. The Western Australian …

A New Species Of Leucospora (Scrophulariaceae) From The Chihuahuan Desert Of Mexico, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

A new species, Leucospora coahuilensis, is described that is similar to Schistophragma intermedia in vegetative and floral characteristics, but has seed characteristics of Leucospora showing the value of combining the two genera under the latter genus.

Morphological Stasis Abd Molecular Divergence In The Intercontinental Disjunct Genus Datisca (Datiscaceae), Aaron Liston, Loren H. Rieseberg, Thomas S. Elias

Aliso: A Journal of Systematic and Floristic Botany

The genus Datisca comprises two species and has an intercontinentally disjunct distribution: D. cannabina is native to southwest and central Asia, whereas D. glomerata is distributed from northern California to northern Baja California. In 1975, Axelrod proposed a geohistorical scenario to account for such "Madrean-Tethyan links," suggesting that these disjunctions resulted from migration across the mid-Atlantic from the Paleogene up to the Neogene, approximately 23 to 65 m.y.a. The two species are quite similar in most phenotypic traits which have been studied to date. The major difference between the two involves their breeding system: D. cannabina is dioecious while D. …

Wood Anatomy Of Ascarina (Chloranthaceae) And The Tracheid-Vessel Element Transition, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Quantitative and qualitative features are presented for 13 collections of 8 species of Ascarina. Wood anatomy is maximally primitive in most respects; moderate exception occurs in the imperforate tracheary elements, which range from tracheidlike (A. solmsiana) to fiber-tracheids (septate in two species). Perforation plates are scalariform, average more than 100 bars per plate, and have bordered bars. Even more significantly, portions of the primary walls in perforations characteristically fail to dissolve; these pit membrane portions range from nearly intact (much like the pit membranes in pits on end walls of tracheids of vesselless dicotyledons) to remnant strands …

Additions And Corrections To The Rust Fungus Flora Of Minnesota, John W. Mccain

Journal of the Minnesota Academy of Science

Ten taxa of rust fungi (Coleosporium campanulae, Puccinia amphigena, P. caulicola, P.longipes var. brevipes, P. mcclatchieana, P. magnusiana, P.punctata var. troglodytes, Tranzschelia arthurii, Uromyces dictyosperma, and U. plumbarius) are reported for the first time from Minnesota. Seven other rust species (Puccinia adoxae, P. distichlidis, P. interoeniens, P. pygmaea, P. typhae, Uromyces andropogonis, and U. geranit) should be removed from the state flora list. Puccinia typhaealso is excluded from the U.S. rust flora list. New Minnesota host plants are reported for fifteen rust pathogens. One host species is deleted for P. polygoniamphibii. Intrastate 200-mile range extensions are reported for four rust …

Dominance Relationships Of Cycloheximide-Resistant Mutants Of Schizophyllum Commune Fr., Marjorie Meier Eerdmans, Sally A. Amundson, Todd A. Reinhart, Keith K. Klein

Journal of the Minnesota Academy of Science

We have isolated several mutants of Schizophyllum commune Fr. able to grow on media containing cycloheximide in concentrations up to 30 mg/L. Genetic analyses of the resistant phenotypes show them to be due to the action of a single gene located on the first linkage group between the A-mating type factor and a gene for an adenine requirement (ade-ll). We have analyzed the growth and development of dikaryons made homoallelic for either the resistant or sensitive alleles as well as the heteroallelic dikaryon. These dikaryons showed different abilities to fruit when placed on media containing various concentrations of cycloheximide. Homoallelic …

Waterlogging : How It Reduces Plant Growth And How Plants Can Overcome Its Effects, Tim Setter, Bob Belford

Journal of the Department of Agriculture, Western Australia, Series 4

Lack of oxygen is the major cause of limited plant growth in waterlogged soils. When soils become waterlogged less gas diffuses to and from the roots through the soil pores; there are changes in concentrations of mineral elements in soil solutions; and toxic products of roots and soil microorganisms begin to accumulate. These changes adversely affect germination, growth and development of plants.

Plant Growth And Survival In Saline, Waterlogged Soils, Ed Barrett-Lennard, Neil Davidson, Richard Galloway

Journal of the Department of Agriculture, Western Australia, Series 4

Waterlogged soils in Western Australia are often salt-affected. Recent research has shown that the interaction between waterlogging and salinity has a far greater adverse effect on plant groivth and survival than either of these two factors individually. The consequences of the combined effects of salt and waterlogging for most plant species are increased salt uptake, reduced growth, chlorosis (yellowing of leaves), defoliation, and death. Salt sensitive agricultural species (nonhalophytes) are more severely affected by this interaction than salt tolerant species (halophytes).

Vegetation Of Saratoga Landing Blackland Prairie, Thomas L. Foti

Journal of the Arkansas Academy of Science

Saratoga Landing Blackland Prairie is a 75-ha site owned by the U.S. Army Corps of Engineers and managed cooperatively with the Arkansas Natural Heritage Commission to protect its blackland prairie community and rare plant species. The site is a complex of prairies and forests, as interpreted from aerial photos and maps. It was substantially prairie at the time of settlement, and forest cover did not increase greatly until after 1951, apparently due to effective suppression of wildfires after that time. Plot sampling characterizes an individual prairie on the site as being dominated by a herbaceous canopy, but with a substantial …

Photosynthetic Competence Of An Endangered Shrub, Lindera Melissifolia, Robert D. Wright

Journal of the Arkansas Academy of Science

Net photosynthesis and water relations were investigated in situ for a population of Lindera melissifolia in northeast Arkansas. Photosynthetic light use efficiency was found to be characteristic of a shade plant. Response of photosynthesis to temperature and CO₂ was insensitive over ranges found during the growing season. High water use efficiency was demonstrated, but under typical conditions of low light this was marginally beneficial. In comparison -with competing understory plants, the species proved to be photosynthetically competent. The data are evaluated in terms of the survival potential of the species.

Sexual Dimorphism And Intersexual Differences In Resource Allocations Of A Dioecious Shrub, Lindera Melissifolia (Walt.) Blume, Dennis J. Richardson, Robert D. Wright, Shannon Walker

Journal of the Arkansas Academy of Science

Morphometric data were gathered to make intersexual comparisons on the morphology and reproductive resource allocation patterns of the rare, dioecious shrub, Lindera melissifolia. Females produced significantly fewer flowers and leaves than did males. No other significant differences could be detected in morphology. Female "clones" exhibit low area coverage and low stem density, which suggests higher costs of reproduction. If this is the case, the deficits produced in resource allocations directed toward sexual reproduction seem to result in increased mortality and/or reduced vegetative reproduction.

Integrated Control Of Soil Insect Pests Of Potatoes, Stewart Learmonth, John Matthiesson

Journal of the Department of Agriculture, Western Australia, Series 4

One of the more difficult aspects of growing potatoes in Western Australia is controlling soil insect pests. These pests have become more troublesome because the highly effective and persistent organochlorine insecticides previously used to control the main soil pests, African black beetle and whitefringed weevil, were deregistered for agricultural use in 1987. Entomologists from the Department of Agriculture and CSIRO in Western Australia are collaborating to develop new management strategies for these pests that rely less on the use of chemical insecticides

Export Oaten Hay For The Japanese Market, Mick Poole, Rob Nussey

Journal of the Department of Agriculture, Western Australia, Series 4

Western Australian hay producers have a foothold in the lucrative Japanese market for forage products. The industry hopes to export about 30,000 tonnes in 1990-91.