H Habitat—Site or place of growth. Hardwood—A collective term for broad-leaved trees, the wood of which may or may not be dense. Heartwood—The physiologically dead, central, usually darker colored portion of the tree trunk. Hybrid—A crossbreed of two species. I Increment—Growth; increase. Incised—Divided into lobes separated by narrow or acute sinuses which extend halfway or more to midrib. Indehiscent—Applied to fruits that do not split open to discharge the seeds, remaining closed at maturity. Indigenous—Applied to plants that are native to a certain locality. Not introduced. Intolerant—Not shade enduring. Requiring sunlight. Involucre—A cluster of bracts subtending a flower. L Lamina—The blade or flattened portion of a leaf. Lanceolate—Shaped like a lance; several times longer than wide, and growing to a point. Lateral—Situated on the side, as the buds along the side of the twig. Leaflets—One of the small blades or divisions of a compound leaf. Leaf-scar—The scar left after a leaf falls. Lenticel—A corky growth on young or sometimes older bark, which admits air to the interior of the twig or branch. Linear—Line-like, long and narrow, with parallel edges. Lobed—Said of leaves that have the margins more or less cut or divided. M Medullary—Pertaining to the pith or medulla. Medullary Ray—Radial lines of tissues crossing the growth of rings at right angles and extending into the bark. Midrib—The central or main rib or vein of a leaf. Monoecious—Bearing male and female flower parts in separate flowers on the same plant. Mucilaginous—Slimy or gummy when touched or chewed. Multiple fruit—A cluster of fruits of separate flowers crowded together and forming what appears to be a single fruit. Examples: mulberry, strawberry, osage-orange fruits. N Naked—Said of buds without scales, and seeds without a covering. Naval Stores—Refers to tar, turpentine, resin, etc. Node—A place on a twig where one or more leaves originate. Nut—A dry, 1-seeded, fruit with a hard indehiscent covering and encased partly or wholly in an involucre or husk. Nutlet—A small nut. O Oblique—Slanting, uneven. Uneven sided. Oblong—About twice as long as wide, the sides nearly parallel. Obovate—Reversed egg-shaped. Obtuse—Blunt Opposite—Said of leaves and buds, directly across from each other. Orbicular—Circular. Oval—Rounded. Ovate—Egg-shaped. Ovoid—Egg-shaped or nearly so.