STALK: 1. This is the main stem of a plant, which ordinarily supports the leaves, flowers, and fruit, as a stalk of wheat or hemp. 2. Or it can describe the pedicel of a flower or the peduncle of a flower cluster, the petiole of a leaf, the stipe of an ovary, or any other similar supporting organ.
STALKLET: A secondary or small stalk.
STAMEN: The male floral organ, bearing the anther, which produces pollen.
STAMINATE: 1. Equipped with or producing stamens. 2. Male, producing stamens but no pistils.
STAMINODE: A sterile stamen.
STAMINODY: The metamorphosis of various floral organs, such as petals, bracts, pistils, etc. into stamens. Compare sepalody, petalody, pistilody.
STANDARD: 1. A tree or shrub that stands alone, unattached to any wall or support, as distinguished from a cordon or an espalier. 2. A plant that is trained to a single stem in tree form; a shrub, such as a rose, can be grafted onto an erect-growing stem; a tree-like cactus may be produced by grafting a trailing or arching species, such as Schlumbergera, onto a tall or columnar species.
STELLATE: Star-shaped.
STELLATE LEAVES: Three or more leaves that surround the stem in a whorl, or radiate like the spokes of a wheel or the points of a star.
STEM: 1. The main (usually aerial) axis of a tree, shrub, or plant; trunk, stalk. 2. The plant part that supports the leaves, flowers or fruits of a plant, as the peduncle of a fruit or the pedicel of a flower; the petiole or leaf-stem.
STEM CUTTING: A cutting taken from a portion of stem.
STEM-LEAF: This is a leaf growing from a stem; a cauline leaf.
STEMLESS: Having no stem; acaulescent.
STENOPETALOUS: Having narrow petals.
STENOPHYLLOUS: Having narrow leaves.
STERILE: 1. Unfruitful; unproductive; not fertile; barren. 2. A staminate or male flower; a fern frond without sori.
STERILIZATION: The process of making sterile; specifically, the process of freeing from living germs.
STERILIZE: 1. To disinfect pruning tools to avoid transferring disease. This is normally done by dipping in a 5% solution of household bleach. 2. To kill all living organisms in soil to control pests; done with soil solarization or chemical treatment.
STERNOTRIBE: Touching the sternum, as certain flowers, especially adapted for cross-fertilization by external aid, have stamens and styles so arranged as to touch the sternum of a visiting insect.
STIGMA: The part of the pistil of a flower, normally on the tip of the style or ovary, which receives pollen.
STIGMATIFEROUS: Having a stigma.
STING: A sharp, hollow, glandular hair that secretes an irritating or poisonous fluid, as in the nettle.
STIPE: 1. The stalk that connects pollinia and viscidium in a pollinarium (of Orchids). 2. A stalk or support, as the stalk-like prolongation of the receptacle of a flower, the petiole of a fern leaf, or the stem that supports the pileus of a mushroom.
STIPEL: A secondary stipule located at the base of the leaflets of a compound leaf.
STIPIFORM: Having the form or appearance of a stipe; stalk-like.
STIPITATE: Having or being supported by a stipe.
STIPULAR: Having or resembling stipules, as stipular glands.
STIPULARY BUDS: Accessory buds in the axils of stipules, as in the apple and pear.
STIPULATE: Having stipules, as a stipulate leaf or stalk.
STIPULE: One of a pair of usually leaf-like lateral appendages found at the base of the petiole of many leaves.
STIPULIFORM: Having the form of a stipule.
STIRPS: A race or permanent variety of plants.
STOCK: 1. The stem, stalk, or trunk of a tree or other plant, as distinguished from roots and branches. 2. A stem or root in which a bud or scion is inserted in grafting; also, a tree, stem, or plant that provides slips or cuttings.
STOLON: A horizontally spreading or arching stem that runs along the ground or just below the surface, which roots at its tip to produce a new plant. Often confused with runner.
STOMA (pl. stomata): A pore on a plant's stem or leaf, which through opening and closing, controls the exchange of gases with the outside.
STONE: 1. The hard, central portion of a drupe, as of a peach. 2. A small, hard, stone-like seed, as of a date.
STONE FRUIT: A fruit with a hard endocarp enveloped in a pulp, as the peach, cherry, and plume; a drupe or drupelet.
STOOL: n. 1. The root or stump of a tree, or of a bush, grass, cane, etc., which produces shoots each year; also, the cluster of shoots thus produced. 2. The mother plant from which young plants are propagated by the process of layering. v. 3. To produce shoots form the root; to form a stool.
STOVE PLANT: A plant from a warm climate that must be grown in a greenhouse in order for it to live.
STRAIN: A group of plants within a variety having some unique quality, such as flower color, drought resistance, or high yield.
STRATIFICATION: The storage of seeds in warm or cold conditions to break dormancy and aid germination. Some seeds won't sprout right after they ripen, but will die if they dry out. They need to have a moist, dark place for a certain period of time before they will germinate. In nature, this is accomplished as the seeds fall to the ground in the fall or early winter and are covered with falling leaves, which provide darkness and moisture. The winter months provide the low temperatures. Gardeners can mimic this by combining the seeds with sand or sand and peat moss and storing them where they will remain moist and cool. Very small seeds can be placed in between cheesecloth and covered with sand so they may be found easily. Seeds may also be mixed with slightly moist sand, placed in jars and stored in the refrigerator.
STOPPING: The removal of the growing tip of a plant with the finger and thumb to encourage bushy growth. Also known as "pinching out".
STREPTOMYCIN: A bactericide used to control several plant diseases, including fire blight.
STRESS: A term used for the total energy with which water is held in the soil. Expressed in any convenient pressure unit.
STRIATE: Striped or streaked; marked with fine lines or channels.
STRIGA: A sharp-pointed appressed bristle or hair-like scale.
STRIGOSE: Rough with strigae; covered with sharp and appressed straight and rigid bristles or hairs, as a strigose leaf or stem.
STRIKE: To take root, as of a slip of a plant.
STRIOLATE: Minutely striate, or striped.
STROBILACEOUS: 1. Resembling or relating to a strobile. 2. Bearing strobiles.
STROBILE: 1. A cone-like structure of sporophylls, as in the horsetails and club mosses. 2. A gymnosperm cone or a hop inflorescence.
STOBILOID: Resembling or relating to a strobile.
STRUMA: A cushion-like swelling of or on an organ, especially at one side of the base of the capsule in many mosses.
STRUMOSE: Bearing a struma.
STUNT: To retard or stop plant growth, usually by accident through exposure to harsh weather or lack of water or nutrients.
STUPOSE: Bearing tufts or matted filaments, like tow.
STYLATE: Having a persistent style.
STYLE: The part of the flower on which the stigma is carried; the ordinarily slender, elongated part of the pistil between the ovary and stigma. (See illustration above in Stigma.)
STYLIFEROUS: Style-bearing; bearing one or more styles.
STYLOPODIUM: One of the double fleshy disks from which the styles in the Umbelliferae (Carrot or Parsley family) arise.