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Full-Text Articles in Botany
Vasicentric Tracheids As A Drought Survival Mechanism In The Woody Flora Of Southern California And Similar Regions; Review Of Vasicentric Tracheids, Sherwin Carlquist
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
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 …
Wood Anatomy And Familial Status Of Viviania, Sherwin Carlquist
Wood Anatomy And Familial Status Of Viviania, Sherwin Carlquist
Aliso: A Journal of Systematic and Floristic Botany
Wood of three species of Viviania from Chile was studied. The wood has growth rings, moderately grouped vessels, helical sculpture in vessels, fiber-tracheids with small pits, and various degrees of storying. Axial parenchyma and rays are absent, regardless of age of stem. These facts are in accord with close relationship to other genera of Geraniaceae sl. Viviania differs from other Geraniaceae in presence of borders on imperforate tracheary elements and presence of endosperm; other differences (polyporate pollen; loculicidal capsules) are shared with some other genera which have familial status according to some authors, subfamilial status according to others. Viviania is …
Observations On Functional Wood Histology Of Vines And Lianas, Sherwin Carlquist
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 …