P Palmate—Radiately lobed or divided from the petiole; hand-like as leaflets of buckeye. Panicle—A loose, irregularly compound flower cluster with flowers on pedicels. Pedicel—The support or stem of a single flower or fruit in a cluster. Peduncle—A primary flower stalk supporting a cluster of flowers or a solitary flower, later the fruit. A fruit-stem. Perennial—Lasting for more than one year. Persistent—Remaining after blooming, fruiting, or maturing. Petiole—The stalk of a leaf. Pinnate—Feather-like with leaflets on both sides of rachis or leaf stalk. Pistil—Seed bearing organ of flower. May consist of stigma, style, and ovary. Pith—The soft central part of a twig or stem. Pod—Any dry, one chambered, dehiscent fruit. Pollen—The dust-like substance from the anthers of a flower. Pollination—The process of bringing the pollen of the male flower in contact with the stigma of the female flower. Pome—A fleshy fruit with a core, such as the apple or pear. Porous—With open tubes (through wood). Prickle—A sharp-pointed, needle-like outgrowth. Pubescent—With short, soft, down-like hairs. Pungent—Acrid or sharp to smell. Pyramidal—Shaped like a pyramid with the broadest part near the base. R Rachis—The stalk supporting the leaflets of a compound leaf. Resin-ducts—A passage for the conduction of resin found in the leaves and wood. Ring-porous—Said of wood which has pores of unequal size, the larger ones being found in the spring wood and the smaller ones in the summer wood.