Herbaceous Dicotyledons Research Articles

Cell length, light and14C-labelled indol-3yl-acetic acid transport inPisum satisum L. andPhaseolus vulgaris L

The putative auxin-transporting cells of the intact herbaceous dicotyledon are the young, differentiating vascular elements. The length of these cells was found to be considerably greater in dwarf (Meteor) than in tall (Alderman) varieties ofPisum sativum L., and to be greater in etiolated than in light-grown plants ofP. sativum cv Meteor andPhaseolus vulgaris L. cv Mexican Black. Under given light conditions during transport these large differences in cell length did not influence the shapes of the transport profiles or the velocity of transport of(14)C-labelled indol-3yl-acetic acid (IAA) applied to the apical bud. However, in both etiolated and light-grown bean and dwarf pea plants the velocity of transport in darkness was ca. 25% lower than that in light. Under the same conditions of transport velocities in bean were about twice those observed in the dwarf pea. Exposure to light during transport increased the rate of export of(14)C from the labelled shoot apex in green dwarf pea plants but not in etiolated plants. The light conditions to which the plants were exposed during growth and transport had little effect on the rates of uptake of IAA from the applied solutions. The results indicate that the velocity of auxin transport is independent of the frequency of cell-to-cell interfaces along the transport pathway and it is suggested that in intact plants auxin transport is entirely symplastic.

Effects of environmental factors and agronomic and storage practices on quality of sugarbeet

The sugarbeet is an herbaceous dicotyledon. The annual world production of sugarbeet exceeds 200 million tons. It supplies 40% of the world's sugar. The sugarbeet, a biennial, normally completes its vegetative cycle in 2 years. During the first year it develops a large succulent root, in which reserve food sugar is stored. During the second year it produces flowers and seeds. Favorable environmental conditions and proper agronomic practices (such as temperatures, climate, day length, fertilization, disease control, control of late growth) are essential for producing high sugar and less impure sugarbeet. Proper nitrogen fertilization increases the yield, but decreases the sugar percentage and juice purity of sugarbeet. Nitrate is the principle source of nitrogen used by sugarbeets. Nitrate uptake and metabolism require energy which is derived at the expense of sugar accumulation. Glutamine in sugarbeet is synthesized mainly in the roots and is transported to the leaves. Estimation and application of the op...

Occurrence of shikimic and quinic acids in angiosperms

Leaves of 83 angiosperms have been made surveyed for quinic and shikimic acids. The quinic acid content was higher in woody dicotyledons than in herbaceous dicotyledons or in the monocotyledons, substantiating the view that its presence may be correlated with the lignification in plants.

Vascular transfer cells in Angiosperm leaves A taxonomic and morphological survey

A study of the fine structure of minor veins of mature leaves of 975 species and 242 families of Angiosperms shows that transfer cells are widespread amongst herbaceous Dicotyledons, are much rarer in woody Dicotyledons, and are virtually absent from the Monocotyledons. The evolutionary significance of the distribution of the cells amongst and within orders, families and minor groupings is discussed.

Developmental Changes in the Vascular Cambium of Polygonum lapathifolium

Developmental changes in the vascular cambium of Polygonum lapathifolium were determined primarily by an analysis of the secondary xylem. The cambium and xylem consist of fascicular and interfascicular regions in this herbaceous dicotyledon. Near the pith vessels are restricted to the fascicular regions of the xylem. During secondary growth vessels are formed in some radial files in the interfascicular regions. Anticlinal divisions are of two types, oblique and lateral. In interfascicular files consisting of fibers only, about two-thirds of the anticlinal divisions are oblique. The oblique partition averages 31% of the length of the dividing initials. In interfascicular files consisting of vessel elements and fibers, there are almost equal numbers of oblique and lateral divisions. The oblique partition averages 37% of the length of the dividing initials in these files. Lateral divisions account for approximately three-fifths of the anticlinal divisions in the fascicular regions, consisting of vessel elements and fibers. The partitions formed in oblique anticlinal divisions average 64% of the length of the dividing cells in the fascicular regions. The frequency of anticlinal division is much higher in files consisting of vessel elements and fibers than in those consisting of fibers only. There is no loss of fusiform initials, except by ray formation. Ray initiation occurs by simple subdivision of fusiform initials. The findings are discussed in relation to the developmental changes in the vascular cambium in plants of different habits.

DEVELOPMENTAL CHANGES IN THE VASCULAR CAMBIUM OF POLYGONUM LAPATHIFOLIUM

Developmental changes in the vascular cambium of Polygonum lapathifolium were determined primarily by an analysis of the secondary xylem. The cambium and xylem consist of fascicular and interfascicular regions in this herbaceous dicotyledon. Near the pith vessels are restricted to the fascicular regions of the xylem. During secondary growth vessels are formed in some radial files in the interfascicular regions. Anticlinal divisions are of two types, oblique and lateral. In interfascicular files consisting of fibers only, about two‐thirds of the anticlinal divisions are oblique. The oblique partition averages 31% of the length of the dividing initials. In interfascicular files consisting of vessel elements and fibers, there are almost equal numbers of oblique and lateral divisions. The oblique partition averages 37% of the length of the dividing initials in these files. Lateral divisions account for approximately three‐fifths of the anticlinal divisions in the fascicular regions, consisting of vessel elements and fibers. The partitions formed in oblique anticlinal divisions average 64% of the length of the dividing cells in the fascicular regions. The frequency of anticlinal division is much higher in files consisting of vessel elements and fibers than in those consisting of fibers only. There is no loss of fusiform initials, except by ray formation. Ray initiation occurs by simple subdivision of fusiform initials. The findings are discussed in relation to the developmental changes in the vascular cambium in plants of different habits.

THE DEVELOPMENTAL ANATOMY OF THE ANNONACEAE. I. EMBRYO AND EARLY SEEDLING STRUCTURE

Development of the epicotylary meristem is delayed; thus, it apparently has no immediate controlling influence on the procambium initiation either in the hypocotyl‐root axis or in the cotyledons. Contrary to the situation found in most herbaceous dicotyledons, the procambium forms a hollow cylinder in the axis of the mature embryo. The first protophloem differentiates simultaneously in the upper part of the hypocotyl‐root axis, at the base of the cotyledons, and in the cotyledons; protoxylem differentiation follows the same pattern as that of the protophloem. The direct vascular connection between the hypocotyl‐root axis and cotyledons is established early in the mature embryo, and the fundamental aspects of transition phenomena are exhibited by the procambium before mature vascular elements differentiate. In the mature embryos, the pattern of lateral differentiation is irregular in that the number of protoxylem elements present at different levels is quite variable.

Studies on the chitinase system in bean and other seeds

1. 1. Seeds of plants, beloging to one family in the monocotyledons and to ten in the woody and herbaceous dicotyledons, possess chitinase and acetylglucosaminidase activity. Then highest activity of chitinase was found in bean, wheat and cabbage, and of acetylglucosaminidase in bean, cabbage, almond and waratah. 2. 2. After ammonium sulphate precipitation, the bean enzymes were fractionated on a column of DEAE cellulose to yield two fractions of chitinase and one fraction of acetylglucosaminidase which had some chitinase activity. 3. 3. The modes of action of the two chitinases (which are free of acetylglucosaminidase) on chitin oligosaccharides differ slightly but in general the action is random. 4. 4. The significance of plant chitinase and acetylglucosaminidase is dissussed.

THE VASCULAR CAMBIUM AND XYLEM DEVELOPMENT IN HIBISCUS LASIOCARPUS

Cumbie, B. G. (U. Missouri, Columbia.) The vascular cambium and xylem development in Hibiscus lasiocarpus. Amer. Jour. Bot. 50(9): 944–951. Illus. 1963.—Circumferential growth of the vascular cambium, as determined primarily by an analysis of the secondary xylem, in Hibiscus lasiocarpus, an herbaceous dicotyledon, occurred through both radial and oblique anticlinal divisions. Divisions to produce segments were less frequent. Although the fusiform initials usually elongated somewhat between successive divisions, this accounted for very little increase in circumference of the cambium. A fusiform initial underwent a specific pattern of anticlinal divisions, determined primarily by its length, at the beginning of cambial activity. There was no loss of fusiform initials, except by ray formation. Most new rays originated only after considerable secondary xylem had been formed. The findings are discussed in relation to circumferential growth of the vascular cambium in woody dicotyledons.

Root initiation in the adult axes of a few dicotyledonous species

Six additional cases of naturally occurring shoot-borne adventive roots on adult axes of herbaceous dicotyledons have been described in this paper.

A Preliminary Key to the Herbaceous Dicotyledons of the Cherokee Strip of Southeast Kansas

This key, based as far as possible on leaf and stem characteristics, includes about 200 of the wild or uncultivated plants of the Cherokee strip of southeast Kansas which have been found and identified by the author. The scientific names have been taken from Gray's Manual of Botany4 and Britton's Man,al of Flora of the United States and Canada.2 In most cases the common names are those used in the locality where the plants were found. In other cases they are taken from Gray4, Britton2, or Georgia3. The territory is described by George I. Adams1 as being a strip of land mainly between the Neosho and Spring Rivers including most of Cherokee county and parts of Labette, Crawford and Bourbon counties, in Kansas. This key has been used and revised but is not to be thought of as being complete. It is offered with the hopes that it may be of use to others in similar attempts for their regions or possibly for entire states.

Physiological and Morphological Correlations in Herbaceous Angiosperms

1. Herbaceous Dicotyledons have developed from arboreal dicotyledonous types by the formation of storage rays about the leaf traces. 2. In the more primitive herbs the foliar rays are shallow longitudinally, but of considerable radial depth. 3. In higher herbaceous Dicotyledons the foliar rays lose in radial dimensions as a result of the thinning of the woody cylinder, but this loss is largely compensated for by their increasing vertical extension, which often carries them through several internodes. 4. In the higher herbaceous Dicotyledons the foliar traces tend to multiply in number with the increased efficiency of the leaf. 5. Another important development in advanced dicotyledonous herbs is the progressive disappearance of cambial activity in the foliar trace, which often, in spite of this, is larger in size than the bundles of the stem. 6. The increase in number and importance of the foliar traces, as well as the greater relative importance of secondary axes in high herbs, leads to the crowding of strands at the node, which in turn results on the one hand in scattered distribution of the bundles in the stem, and on the other to formation of amphivasal strands. 7. The disappearance of secondary growth in foliar traces of advanced dicotyledonous herbs appears to be explainable on the grounds of physiological advantage. 8. Absence of secondary growth extends from the leaf traces to the rest of the bundles situated in the stem, and a condition practically monocotyledonous results.

THE RÔLE OF SEDGES IN SOME COLORADO PLANT COMMUNITIES

Every botanist is well aware of the large part taken by sedges in the vegetation of lake shores and swampy areas. For the eastern United States the species involved are well known, as also their relative importance in different stages of succession. Sedges of lake shores in the Rocky Mountains have been referred to by Clements (i), Ramaley and Robbins (7), Ramaley (4), and Robbins (9). In the present paper additional facts are given as to sedges of pondsides together with a series of observations on sedges of mesophytic and xerophytic habitats. This paper is based upon studies carried on largely from the University of Colorado Mountain Laboratory at Tolland, Colorado. Statements in the paper apply chiefly to the northern part of the state and to the mountain districts rather than to the plains. All species mentioned are well-known constituents of the Colorado flora. The nomenclature employed is that of Rydberg's Flora of the Rocky Mountains and the Adjacent Plains (New York, I9I7). The various life zones are given the following names in accordance with customary usage: Plains, Foothill, Montane, Subalpine, Alpine (4). Sedges exist chiefly in primitive communities or unstable situations. An area in a region that is climatically mesophytic becomes eventually either forest or grassland in which sedges have a very small place. So also, a climatically xerophytic area grows poor in sedges as the ultimate type of vegetation appears. Most sedges are aquatics or marsh plants or else they are xerophytes. Only a few are true mesophytes, and even these are likely to become crowded out by grasses and herbaceous dicotyledons in a meadow which has developed from marsh. Meadow or prairie of xerarch origin is also typically without sedges, the xerophytic sedges of more primitive stages disappearing before the meadow stage is reached. In the following systematic account the various genera of Cyperaceae are briefly considered, but chief attention is given to Carex.

Societies and Academies

PARISAcademy of Sciences, Sept. 20.—Résumé of the observations of the sun and of the planets Mercury, Venus, Mars, Jupiter, Saturn, and Uranus, made at the Par s Observatory during the year 1874, by M. Leverrier.—On a remarkable anatomical peculiarity of the rhinoceros, by MM. Paul and Henri Gervais.—Addition to the note relating to M. Bienayme's theorem, by M. J. Bertrand.—Chemical and spectroscopic characters of a new metal, Gallium, discovered in a blende from the Pierrefitte mine, Argeles Valley, Pyrenees, by M. Lecoq de Boisbaudran. An account of this metal has already appeared in our columns.—Theorem on the composition of co-variants, by M. C. Jordan.—Preliminary note on the function of the protective sheath in herbaceous Dicotyledons, by M. J. Veique.— On a vertical column of vapour observed from a balloon, by M. W. de Fonvielie.—On the development and structure of interior foliaceous glands, by M. Joannes Chatin.—Existence and development of the Avicula contorta zone in the Isle of Corsica, by MM. L. Dieulafait and Hollande.—On the theory of hail, by M. E, Renou.—On hailstones picked up at Criel-sur-Mer during the storm of August 12, 1875, by M. A. Landrin.