Botany Commons^™

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.

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.

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.

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.

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. …

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.

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.

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.

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 …

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 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 …

Wood Anatomy And Relationships Of Montinia, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Quantitative and qualitative data are presented on wood anatomy of root, basal stem, and upper stem of Montinia caryophyllacea. Anatomy of twig wood of Kaliphora madagascariensis is compared with these results, as is the data of Ramamonjiarisoa (1980) on wood of the genus Grevea. Features common to the three genera in wood as well as other portions of the plant are reviewed; these are consistent with the interpretation that Montinia and Kaliphora are very close to each other, despite previous positions of the two genera in Saxifragaceae and Comaceae, respectively. Grevea, although more distant from Montinia than …

Assessing The Utility Of Isozyme Number For Determining Ploidal Level, Loren H. Rieseberg, Douglas E. Soltis

Aliso: A Journal of Systematic and Floristic Botany

In order to evaluate the utility of isozyme number for estimating ploidal level in ancient polyploid (paleopolyploid) plant species, isozyme number was determined for species of the putatively paleopolyploid genus Helianthus with n = 17, and compared with those of a species of Heliomeris with n = 8. Electrophoretic examination of 13 enzymes revealed the presence of nine duplicated isozymes in Helianthus annuus and Helianthus bolanderi and six duplicated isozymes in Heliomeris multiflora. Thus, there is little difference in isozyme number between ploidal levels. It is suggested that the lack of strong concordance between isozyme number and ploidal level …

Follar Flavonoids Of Keckiella Ternata, Ron Scogin

Aliso: A Journal of Systematic and Floristic Botany

The major foliar phenolics of Keckiella ternata are quercetin 3-O-glucoside, kaempferol 3-O-glucoside, and acteoside (= orobanchin). The occurrence of flavonols in K. ternata is anomalous compared with other species of Keckiella and Penstemon, in which leaf flavonoids are based on luteolin and 6-hydroxyluteolin. The occurrence of foliar flavonols in K. ternata is interpreted as an advanced, derived condition.

Taxonomy And Natural History Of Hydnora (Hydnoraceae), Lytton J. Musselman, Johann H. Visser

Aliso: A Journal of Systematic and Floristic Botany

Hydnora is a genus of subterranean holoparasitic herbs found in arid and semiarid regions of Africa, Madagascar, and the southwestern part of the Arabian peninsula. Results from field and herbarium studies suggest the genus consists of four or five species, although more than 12 have been described. The recent rediscovery of H. triceps, a plant that had remained uncollected for a century, supports the need for additional field work. Taxonomic research has been impeded by a paucity of collections, which are often fragmentary in nature and poorly preserved. Supraspecific classification, species complexes, floral biology, and uses are discussed.

Allozyme Variation In Hellianthus Praecox Ssp. Hirtus, A Rare Sunflower From Southern Texas, Loren H. Reiseberg, Michael F. Doyle

Aliso: A Journal of Systematic and Floristic Botany

Allozyme data were used to evaluate the genetic status of a rare endemic sunflower from Texas, Helianthus praecox ssp. hirtus. Comprising approximately 200 plants, the taxon is presently known from a single population in the Carrizo Springs region of Southern Texas. Electrophoretic examination of 17 enzyme loci revealed that ssp. hirtus is genetically similar to, but distinct from, the two more widespread subspecies of H. praecox: ssp. praecox and ssp. runyonii. Levels of genetic variation in the single population of ssp. hirtus (P = 0.4 7, A = 1.88, and H = 0.17) are similar to those …

Wood Anatomy Of Tasmannia, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Quantitative and qualitative data are presented for 11 collections of eight taxa. Diameter and length of tracheids are related to plant size, but populations in cooler locations have narrower and shorter tracheids than one would expect on the basis of plant size and age, and smaller tracheids are believed to be of selective value in these environments because of their resistance to embolisms. Vesturing is absent from tracheids in taxa from warmer localities but pronounced in colder places; this, too, is a probable mechanism for resistance to embolism formation. Helical thickenings are reported for one collection of T. insipida; …

Photosynthesis Of Arid And Subtropical Succulent Plants, Irwin P. Ting

Aliso: A Journal of Systematic and Floristic Botany

The hypothesis of Crassulacean acid metabolism (CAM) is that it is a physiological adaptation to arid or otherwise dry habitats. Stomata are closed during the day and open at night when the evaporative demand is low. Thus exogenous CO₂ is fixed at night with relatively little water loss. CAM is typically found in succulents occurring in desert and dry Mediterranean regions, but not in the cold deserts of Asia. Recently, it has become known that many arid tropical succulent plants are CAM as well, particularly those growing epiphytically. The vegetation of St. John, U.S. Virgin Islands, ranges from desertlike …

Wood Anatomy Of Cercidium (Fabaceae), With Emphasis On Vessel Wall Sculpture, Sherwin Carlquist

Aliso: A Journal of Systematic and Floristic Botany

Quantitative and qualitative data are presented for wood anatomy of the seven species of Cercidium (including two subspecies of C. floridum as well as the hybrid C. x sonorae) currently recognized. Data on wood of Parkinsonia are presented for purposes of comparison. Vessel walls of Cercidium show unusual sculpture: coarse excrescences termed verrucae here, crateriform pits, and grooves interconnecting pit apertures. These plus crystal distribution, presence of septa in fibers, pit diameter, presence of vasicentric tracheids, and presence of diagonal vessel aggregations are probably species distinctions to various degrees. The crystal-bearing fibers of Cercidium, some of which have …

Leaf Anatomy Of The Goetzeaceae, Scott Zona

Aliso: A Journal of Systematic and Floristic Botany

A comparative study of the leaf anatomy ofthree species of three genera of Goetzeaceae (Henoonia, Goetzea, and Espadaea) revealed a number of characteristics common to all genera, viz. anomocytic stomata, sinuous anticlinal epidermal walls, both glandular and uniseriate nonglandular trichomes, crystal sand and druses in the mesophyll (often in the same cell), and intraxylary phloem. The mid veins of these species exhibit secondary growth and parenchymatous rays. The unifying anatomical features of this family are, however, not uncommon in the Solanaceae. The results of this study support placement of the Goetzeaceae in or very near Solanaceae. …

Distribution Of Vessel Diameter In Ring-Porous Trees, D. W. Woodcock

Aliso: A Journal of Systematic and Floristic Botany

The wood anatomy of ring-porous trees presents difficulties of description and measurement. Information regarding the distribution of vessel diameters within the yearly growth increment may be of use of interpreting wood anatomy and function. Two distributional patterns can be recognized in the trunk xylem of the five ring-porous species investigated. The following terms are proposed: graduated-unimodal, to refer to ring-porous woods with one population of vessels, and graduated-bimodal, to refer to woods with two distinct peaks in vessel frequency.

Taxonomy And Morphology Of Aporomyces (Laboulbeniales), Richard K. Benjamin

Aliso: A Journal of Systematic and Floristic Botany

Thaxter's original circumscription of Aporomyces (Laboulbeniales) is emended in this study of the eight known species of the genus, three of them new: A. byrrhini, A. lutrochi, and A. physemi. The new species, as well as A. subulatus, A. szaboi, A. trinitatis, and A. uniflagellatus (type), are dioecious and occur on beetles belonging to the Limnichidae (Coleoptera: Dryopoidea). The eighth species, A. perpusillus, appears to be monoecious and occurs on Staphylinidae (Coleoptera: Staphylinoidea). All taxa are described and illustrated with line drawings and/or photographs. Aspects of thalloid structure and development are summarized. Aporomyces …

Factors Limiting Sexual Reproduction In Platanus Wrightii In Southeastern Arizona, Jane H. Bock, Carl E. Bock

Aliso: A Journal of Systematic and Floristic Botany

Arizona sycamore (Platanus wrightii: Platanaceae) is a riparian tree of the southwestern United States and adjacent Mexico. It is failing to reproduce in certain canyons where mature, seed-producing trees of this species occur. Three hypotheses were tested to explain this reproductive failure: I) the presence of domestic cattle prevents reproduction, 2) seeds produced in certain canyons are inviable, and 3) annual flash floods destroy seedlings and young saplings but not the large, mature trees.

Canyons, either grazed or ungrazed by domestic animals, were surveyed for the presence of seedlings and young trees. In the laboratory, seeds were tested …

Systematics Of Nama (Hydrophyllaceae), John D. Bacon

Aliso: A Journal of Systematic and Floristic Botany

Lemmonia has been maintained as a monotypic genus, despite the fact that it is morphologically very similar to several species of Nama. The major basis for this separation resides in the reportedly coalescent filament bases of Lemmonia as contrasted with the distinct filaments of Nama. Examination of corollas of Lemmonia with the scanning electron microscope has revealed that the filaments of the taxon are distinct. There is, then, no qualitative basis upon which to found Lemmonia, and the taxon is transferred to Nama.

Plant Taxonomy In My Time, Lincoln Constance

Aliso: A Journal of Systematic and Floristic Botany

No abstract provided.

High-Elevation Draba (Cruciferae) Of The White Mountains Of California And Nevada, Reed C. Rollins, Robert A. Price

Aliso: A Journal of Systematic and Floristic Botany

Accurate identification of the species of Draba at high elevations in the White Mountains of eastern California and adjacent Nevada has been impossible because of frequent misinterpretations in the literature and the lack of a coherent source of information. A preliminary investigation of newly collected material suggested that several species of Draba, endemic or nearly so to these mountains, had not been recognized. Descriptions and relevant comparisons are given for a new combination, D. californica, and two new species, D. monoensis and D. subumbellata. Specimen citations for all taxa of Draba occurring at high elevations, roughly above …