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Full-Text Articles in Plant Sciences
Wood And Bark Anatomy Of The New World Species Of Ephedra, Sherwin Carlquist
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
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 …
Wood And Bark Anatomy Of Empetraceae; Comments On Paedomorphosis In Woods Of Certain Small Shrubs, Sherwin Carlquist
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 …
Steps Toward The Natural System Of The Dicotyledons, William C. Dickison
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 …
Wood Anatomy Of Ascarina (Chloranthaceae) And The Tracheid-Vessel Element Transition, Sherwin Carlquist
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 …