California Press, 1951. Sargent, C. S. _Manual of the Trees of North America._ Second Edition. Houghton Mifflin Co., 1922 (_at Project Gutenberg_). Vines, R. A. _Native East Texas Trees._ Houston Museum of Natural History, 1953. Vines, R. A. Trees, _Shrubs and Woody Vines of the Southwest._ The University of Texas Press, 1960. [Illustration: Cross Section of the Trunk of an Oak Tree.] A. Cambium B. Inner bark C. Outer bark D. Sapwood E. Heartwood F. Pith G. Ray [Illustration: TWIG FEATURES] Terminal Bud False Terminal Bud Twig Scar Bud Scales Superposed Bud Lateral Leaf Buds Bundle Scar Flower Bud Leaf Scars Lenticel Stipule Scar Terminal Bud Scale Scars Pith Chambered Solid TWIGS AND LEAVES [Illustration: TYPES OF TWIG BRANCHING] Alternate Whorled Opposite [Illustration: LEAF TYPES] Simple Compound Doubly Compound Opposite Leaves Alternate Leaves Awl-Shaped Needles Pine Needles Scale-like Needles [Illustration: PARTS OF LEAF] Lamina or blade Base Stem Apex Leaf margin Primary vein Secondary or lateral veins Petiole (Sessile leaves have no petiole but are attached directly to the stem) LEAF SHAPES [Illustration: LEAF FORMS] Lanceolate Ovate Obovate Star-shaped Linear or Rectangular Heart-Shaped or Orbicular Oval Elliptical Deltoid [Illustration: LEAF APEXES] Acuminate Acute Obtuse Truncate Bristle Pointed Rounded [Illustration: LEAF MARGINS] Entire Dentate Toothed or Serrate Sinuate or Wavy Doubly Serrate Lobed Incised [Illustration: LEAF BASES] Wedge-Shaped or Cuneate Oblique or One-Sided Rounded Heart-Shaped or Cordate Truncate or Square [Illustration: THE COMPLETE FLOWER] Stamen Anther Filament Sepal Receptacle Petal Pistil Stigma Style Ovary Peduncle Sepals collectively designated as _calyx_. Petals collectively designated as _corolla_. The ripened ovary comprises the fruit. Ripened ovules of the ovary comprise the seed of the fruit. A flower lacking either calyx, corolla, stamens, or pistil is an incomplete flower. If the male and female flower parts occur in separate flowers on the same tree the species is said to be _monoecious_. If the male and female flowers occur on separate trees, the species is said to be _dioecious_. [Illustration: FLOWER CLUSTERS] Spike Catkin or ament Cylindrical cyme Flat-topped cyme Raceme Panicle Corymb Umbel Compound umbel Head