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Morphology And Anatomy Of Foliar Nectaries And Associated Leaves In Mallotus (Euphorbiaceae), Thomas S. Elias, Sun An-Ci

Aliso: A Journal of Systematic and Floristic Botany

The morphology and anatomy of the foliar nectaries and associated leaves offour species of Mallotus (Euphorbiaceae) were studied. Light microscopic observations of paraffin- and plastic-embedded specimens were complemented with scanning electron micrographs. Leaf anatomy of the four species is typical of large mesophytic plants. Aattened foliar nectaries are shown to be composed of specialized epidermal cells. The nonvascularized nectaries consist of narrow columnar cells each with a large nucleus, numerous vacuoles, and dense cytoplasm. Subglandular parenchyma cells have more pronounced nuclei, more vacuoles and denser cytoplasm than do typical laminar parenchyma. Structurally, these nectaries are similar to those found in …

Taxonomy Of The Allium Tribracteatum (Alliaceae) Complex, William R. Mortola, Dale W. Mcneal

Aliso: A Journal of Systematic and Floristic Botany

Allium tribracteatum and related species present a confusing array in California. Previous attempts at classification have been largely unsuccessful and keys that are available are unworkable. Herbarium and field studies were initiated to ascertain if previously overlooked characteristics could be found that would elucidate relationships within the group. Members of the complex were examined morphologically and cytologically. Based on these investigations four of the seven previously described taxa are considered valid: A. cratericola, A. obtusum, A. tribracteatum, and A. yosemitense. Allium tribracteatum is redefined and A. obtusum is divided into two varieties. Allium obtusum var. conspicuum …

Observations On Functional Wood Histology Of Vines And Lianas, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Types of xylem histology in vines, rather than types of cambial activity and xylem conformation, form the focus of this survey. Scandent plants are high in conductive capability, but therefore have highly vulnerable hydrosystems; this survey attempts to see what kinds of adaptations exist for safety and in which taxa. A review of scandent dicotyledons reveals that a high proportion possesses vasicentric tracheids (22 families) or true tracheids (24 families); the majority of scandent families falls in these categories. Other features for which listings are given include vascular tracheids, fibriform vessel elements, helical sculpture in vessels, starch-rich parenchyma adjacent to …

A Taxonomic Revision Of Chilopsis (Bignoniaceae), James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

The genus Chilopsis contains one species, C. linearis, with two subspecies: subsp. linearis of the Chihuahuan Desert characterized by erect, straight leaves, and subsp. arcuata of the Sonoran and Mojave deserts with longer, arcuate leaves and other distinguishing characteristics. Populations of subsp. linearis east of the Sierra Madre Oriental in eastern Mexico have woolly stems and are described as a new variety, tomenticaulis. Relationships between Chilopsis and Catalpa are discussed and data are presented supporting continued recognition of Chilopsis as a distinct genus.

Xerospiraea, A Generic Segregate Of Spiraea (Rosaceae) From Mexico, James Henrickson

Aliso: A Journal of Systematic and Floristic Botany

The xeromorphic Mexican spiraeas (S. hartwegiana and S. northcraftii) are shown by cladistic and phenetic analysis to be more closely allied to Petrophytum, Kelseya, and Luetkea than to the more mesophytic Spiraea. Within Spiraea the Mexican spiraeas appear more closely related to the Old World subgenus Metaspiraea. The xeromorphic Mexican spiraeas, as well as Petrophytum, Kelseya and Luetkea, are considered to be New World derivitives of Old World Spiraea subgenus Metaspiraea that have become part of the Madro-Tertiary Geoflora, with each genus achieving some level of xeromorphic adaptation. The Mexican spiraeas are thus considered generically distinct and are …

Monographing In The 1980s, Ghillean T. Prance

Aliso: A Journal of Systematic and Floristic Botany

The production of taxonomic monographs is discussed in light of the modern tools that are available for their preparation. There is a great need for more monographs since much of the world's flora is not treated in contemporary revisions. These should be a balance between the traditional aspects that must still be employed such as the nomenclatural framework and the consultation of type specimens, and the use of modem techniques, computer data analysis and field work. The importance of field studies in association with monographic studies is stressed both to give a better understanding of traditional morphological features and to …

Root And Foliar Diseases Of Wheat On Sandplain In The Geraldton Region., J. Wilson

Experimental Summaries - Plant Research

A project funded by Wheat Industry Research Council and Wheat Industry Research Committee of W.A. Interactions between stubble, rotation, ripping and nitrogen, ECRS, 85C53. The effect of type of cultivation implement, and time of cultivation, ECRS, 85C54. The effect of fumigation, ECRS, 85C91. Residual ripping responses from 1984, 84C15.

The Ecology Of Skeleton Weed In Western Australia, Afghan Thistle Ecology, Reproductive Biology Of Gorteria Personata., J. Dodd

Experimental Summaries - Plant Research

1. The ecology of skeleton weed (Chondrilla juncea L.) in Western Australia. Seed production and water use in the glasshouse, 84PE18. Seed production and water use by field-grown skeleton weed, 84BA17, 84BA18. Seedling root growth 85PE54 2. Afghan thistle (Solanum hoplpetalm) ecology Winter rosette survival 84N050. Regenerative ability of S. hoplopetalum, 85PE51. 3. Reproductive biology of Gorteria personata. Gorteria personata Floral biology Seed content of burrs

The Ecology Of Skeleton Weed (Chondrilla Juncea) In Western Australia, Demographic Aspects Of Wild Radish (Raphanus Raphanistrum) Populations In Lupin Crops And Identification Of Populations Of Mesquite (Prosopis Spp) From The West Pilbara Region., F. D. Panetta

Experimental Summaries - Plant Research

To determine what forms of skeleton weed are present in Western Australia and to map their respective distribution. To determine, on the basis of climatic characteristics, the suitability of various areas within the Western Australian wheatbelt for infestation by skeleton weed. To determine the amounts, viability and dormancy status of seeds produced by field-grown plants during summer and autumn months. To determine the effectiveness of conventional tillage practices in limiting establishment of skeleton weed seedlings. To determine the regularity with which seedling establishment occurs under field conditions and how the probability of establishment is affected by the time of germination. …

Public Response To "Guidelines For Managing Aspen", Norbert V. Debyle

Aspen Bibliography

No abstract provided.

Nitrogen And Phosphorus Compound Fertilisers, M G. Mason, J. W. Bowden

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

Nitrogen and phosphorus are two vitally important elements for plant growth which are deficient in most soils throughout Western Australia's agricultural areas.

Both nitrogen and phosphorus can also be applied in appropriate compound fertilisers which can be drilled with the seed, thus making their handling much easier. However, excessively high rates can depress plant emergence and may lower crop yields.

Wind Dispersal In Californian Desert Plants: Experimental Studies And Conceptual Considerations, Jay C. Maddox, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Because of the important role wind is alleged to have in dispersal of fruits and seeds in desert plants, diaspores were collected for experimental study of 14 species from two Sonoran Desert localities of Imperial Co., California. Field observations on natural dispersal of these species also were made. Although all 14 species were not judged to be primarily adapted to anemochory, tests on air transport capability were made using a calibrated and modified seed-blowing machine. Diaspores were tested individually and results for 20 trials averaged for each experimental condition. In one series of tests, lofting ability was determined. In other …

Experimental Studies On Epizoochorous Dispersal In Californian Plants, Sherwin Carlquist, Quinn Pauly

Aliso: A Journal of Systematic and Floristic Botany

Experiments studying degrees of adherence ability to various surfaces were undertaken with presumably epizoochorous diaspores of 14 native and eight introduced species from southern California. A commonly available laboratory shaker was modified so as to provide a standard means for dislodging diaspores from surfaces. Diaspores were dropped onto a cloth-covered board and percentages of dislodged diaspores recorded after inversion and then after intervals of shaking. Three fabrics were used: a velvet with short pile, an artificial wood with short curly strands, and a furlike fabric with straight strands. Attachment to the velvet was nil for most species, showing that a …

Equilibrium Moisture Properties Of Corn Cobs, G. M. White, Thomas C. Bridges, Samuel G. Mcneill, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

Equilibrium moisture content-equilibrium relative humidity data for broken corn cobs have been determined for both desorption and adsorption conditions for three temperature levels and five moisture levels. The Modified Henderson and Chung equilibrium moisture equations have been fitted to these data by using non-linear regression procedures to estimate equation parameters. Both equations adequately represented the experimental data. A test of varietal differences indicated no significant difference in cob desorption ERH values for three selected corn varieties.

Vasicentric Tracheids As A Drought Survival Mechanism In The Woody Flora Of Southern California And Similar Regions; Review Of Vasicentric Tracheids, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Vasicentric tracheids are defined as tracheids present adjacent to vessels in a wood which also possesses libriform fibers or fiber-tracheids as imperforate tracheary elements. Vasculartracheids would correspond with this definition, but are defined as occurring only in latewood, whereas vasicentric tracheids occur throughout a growth ring or in wood of a diffuse-porous species. V asicentric tracheids offer a subsidiary conducting system which can supply stems and leaves when the vessels to which vasicentric tracheids are adjacent fail because of air embolisms. True tracheids (present as the sole imperforate tracheary element type in the woods in which they occur) have much …

Vegetative Anatomy And Familial Placement Of Tovaria, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Leaf, stem, node, and wood anatomy are examined for Tovaria pendula collections from Peru. Features claimed to separate Tovaria from Capparaceae have hitherto included exstipulate nodes and paracytic stomata. However, the presence of stipules and of anomocytic stomata is demonstrated, together with occurrence of probable myrosin cells in leaves and stems. The nodal type is one reported from Capparaceae. This leaves features of gynoecium and fruit, chiefly, as means of distinguishing Tovaria from Capparaceae: ovary nonstipitate, 6-8 loculate, with axile placentation; fruit a berry; ovules with two nucellus layers; endosperm well developed. These features are considered insufficient to maintain recognition …

Residual Value Of Legumes., J. Hamblin, R. Delane, G. Adam, A Bishop

Experimental Summaries - Plant Research

This report examines the residual value of lupins and several other species grown at ECRS in 1984 on the yield of wheat in 1985 (85 C 25). 85 C 46 examined the residual effect of several lupin species and varieties grown under different nutritional treatments in 1984 at two sites differing in rainfall on wheat yields in 1985. 85 C 47 examines the interaction between levels of applied potassium and deep cultivation (ripping) on the yield of wheat at a low K, dry site.

Report on 85 C 27, 85 C 46 and 85 C 47.

Grain Legume Agronomy Programme., G. H. Walton

Experimental Summaries - Plant Research

Lupin agronomy, 85AL4, 85AL6, 85M05, 85PE13, 81M029, 81M030, 81M027. Grain legume crop comparisons, 85LG23, 85LG24, 85LG25, 85E23, 85GE28, 85C71, 85ME35, 85KA7, 85E2, 85N5, 85N04, 85SG2, 85E34, 85LG38, 85LG40, 85MN2, 85MD25, 85MN1.

Molybdenum Nutrition., M. M. Riley

Experimental Summaries - Plant Research

Field trials. Residual value of Molybdenum on an acid soil, 81N040. Residual value of Molybdenum on an acid soil, 81M2. Residual value of Molybdenum of an acid soil, 81LG12. Residual value of Molybdenum on an acid soil, 82N07. Residual values of different Molybdenum sources, 84Me10. Residual values of different Molybdenum sources, 84Ge49 Forms and rates of soil and seed applied Molybdenum, 84Me9. Molybdenum requirements of wheat, triticale and lupins, 84Me8. Residual values of Molybdenum with different nitrogen sources, 85M40. The Molybdenum nutrition of various crop and pasture cultivars, 85Mo42. Molybdenum with pre-emergent herbicides, 85TS21. Glasshouse experiments. Reactions of Molybdenum with …

Guidelines For Managing Aspen, The Aspen Panel

Aspen Bibliography

No abstract provided.

Changes In Forest Soils Following Clearcutting Of Pine Forests In The Ouachita Mountains Of Arkansas, Harlan R. Stoin, Bajuri Bin Kadmin, Lyell F. Thompson

Journal of the Arkansas Academy of Science

Soil characteristics of the mineral surface soil (0-6 cm) on three small watersheds in the Ouachita Mountains of Arkansas from which the pine forests have been clearcut, crushed, and burned for site preparation were studied for the first two years following clearcutting and compared to soils from adjacent uncut pine forest watersheds. Following clearcutting and burning, soil pH was generally higher than in uncut forest soils. The greatest pH differences occurred within several months of burning and generally decreased through the end of the second year. Soil organic matter content was lower immediately following clearcutting and burning and increased to …

Some Effects Of Viterra 2 Hydrogel On Soil Physics And Plant Growth, Julia E. Maserang

Masters Theses

The effects of hydrogel on various aspects of plant growth and soil physics were determined for Tagetes patula (marigold) and Vinca rosea growing in 'PRO-MIX' soilless potting medium.

The addition of hydrogel at various concentrations to the potting medium increased the water-holding capacity of the medium, thus extending the hours-to-wilt of plants growing in this medium. While hydrogel had no effect on plant height, flowering time, plant color, soil pH or soil nitrate concentration, plant weight and flower number did appear to increase between the control and highest hydrogel treatment. As hydrogel concentration within the medium increased, percent total seed …

A Novel New Species Of Syncephalis, Richard K. Benjamin

Aliso: A Journal of Systematic and Floristic Botany

Syncephalis hypogena, a new species isolated from soil collected in southern California is described from cultures on Mortierella bisporalis. Salient features of its vegetative development and reproduction, both sexual and asexual, are illustrated with photographs and line drawings. The species is distinguished from all other members of the genus in typically producing merosporangia from the lower rather than the upper hemisphere of the terminal ampulla of the sporangiophore.

Response Of Five Spring Wheat Cultivars To Drought, Gregory Keith Hess

Electronic Theses and Dissertations

Response of plants to water stress are numerous and interrelated. Morphological traits and growth patterns have been studied and reviewed extensively. Root growth patterns, leaf area and thickness, presence of cuticle hair and waxes, leaf movement, and wilting are only a few traits studied. Metabolic functions and how water stress affects these processes through stomatal behavior, transpiration rates and carbon dioxide exchange rates have also been reviewed. Plant breeders are continually searching for traits which aid in selecting for high yielding genotypes in any one environment. Moisture is often limiting in South Dakota's environment, leading to relatively low grain yields …

Aspen Community Types Of Nevada, W. F. Mueggler

Aspen Bibliography

No abstract provided.

Frontiers In Plant Science: Transcripts From A Symposium Sponsored By The Minnesota Academy Of Sciences, Gretchen Hagen, David D. Biesboer

Journal of the Minnesota Academy of Science

No abstract provided.

Beating The Blackberry, J H. Moore, E. B. Hoskins

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

The blackberry is an aggressive, strongly-growing plant that has spread throughout parts of the south-west of Western Australia.

Although most blackberry infestations on agricultural land have been dramatically reduced since compulsory control measures were introduced 30 years ago, about 3,600 hectares are still infested today.

Recent research has shown that three new herbicides are highly effective against blackberry, and much safer to use than the older ones.

Effective biological control of blackberry may also be possible.

Effects Of Litter On Aquatic Macrophyte Germination And Growth, Mark F. Carter, Forrest E. Lane, James B. Grace

Journal of the Arkansas Academy of Science

In Arkansas, during seasonal drought periods, lake water levels drop leaving exposed mudflats which are primary sites for seedling establishment. Commonly, these exposed mudflats are partially covered with decomposing litter from previous stands of aquatic plants. In this study, aqueous leachates from the litter of four macrophytes, Eleocharis quadrangulata, Justicia americana, Polygonum lapathifolium, and Potamogeton nodosus, were used to test for chemical interference with germination and seedling growth. Only Justicia americana leachate was found to affect the growth of several of the test species. The potential for chemical interference by Justicia litter was evaluated further using extracts of acidified leachate. …

Observations And New Records Of Ferns Naturalizing In Arkansas, James H. Peck, Lance Peacock, William M. Shepherd

Journal of the Arkansas Academy of Science

No abstract provided.

Effects Of Gamma Radiation On Salix Nigra Marsh Cuttings, Roy Z. Gehring

Journal of the Arkansas Academy of Science

Dormant cuttings of Salix nigra Marsh, were exposed to gamma radiation from a cobalt-60 source at a dose rate of 1110 roentgens (r) per minute. Exposure doses ranged from 50 r through 100 Kr with 100% mortality at 10 Kr. Low doses of ionizing radiation apparently stimulated growth, while higher doses progressively retarded growth. The growth of the staminate catkins was inversely proportional to total exposure dose (increased dose resulted in progressively decreased growth). Determination of growth rates at different intervals post-irradiation indicated recovery of the surviving fraction of the irradiated cuttings. At ninety days, the highest growth rate occurred …