Glossary Of Houseplant Terms

Author: Celeste BoothNo Comments

Blooming, Care and Culture, Classification, Diseases, Growing Indoors, Growing Outdoors, Insects, Propagation

If you’re not sure about the meaning of a word the following short definitions should help.

• Acidic – Soil with a pH below 6.5, as is typical of soil comprised of peat moss or tree by-products, such as bark. Acidity can be reduced by adding lime, a mineral powder made from ground limestone (look at your plant’s specific growing guidelines to be sure this process won’t be harmful).

• Adventitious Root – A root that emerges from above the soil line, often in unusual places such as leaves or nodes. Plants that develop adventitious roots are easy to propagate from stem cuttings.

• Aerial Root – A root that emerges from a plant’s stem above the soil line. An aerial root may eventually reach down into the soil or attach itself to a support post.

• Alkaline – Soil with a pH above 7.0, which naturally occurs in low rainfall areas and some other places where abundant weathered limestone is present. Alkaline soil can be made more acidic by adding sulphur, which is produced from ground sulphuric rock (again, look at your plant’s specific growing guidelines to be sure this process won’t be harmful).

• Annual – A plant that grows from seed, to flower, and then to seed again within one year.

• Anther – The male reproductive part of a flower that bears the blossom’s pollen supply. The stalk-like structure that supports the anther is called the stamen.

• Areole – A plant structure unique to cacti from which spines or hair emerge. Areoles are often round, raised bumps, but in some species they are difficult to see.

• Auxins – Plant hormones that stimulate plant cell growth, particularly the growth of new roots. Auxins are usually sold as rooting powder, but nurseries also use liquid forms for some plants.

• Bonsai – Training method in which plants are maintained at a small size and often set in miniature landscapes that dramatize primal forces of nature such as wind, gravity, and the passage of time.

• Bract – A specialized leaf that frames a plant’s true flower. Bracts may be very leaf like, as in poinsettia, or they may resemble blossoms, as in bromeliads. Bracts are usually more long-lived than a plant’s flowers, which are typically fleshy and fragile.

• Bulb – A type of storage root that includes cells that are poised to grow into leaves and flowers. Most bulbs are comprised of layered scales, like an onion’s. Leaves and flowering stems emerge from the center of the top of a true bulb.

• Cachepot – A container, usually decorative, in which a slightly smaller container can be placed.

• Callus – A cut plant part that dries to form a solid surface that prevents the loss of plant sap while sealing out water, fungi, and bacteria.

• Chloroplasts – Special cells within plant leaves that take in light and transform it into energy.

• Chlorosis – Yellowing of leaves, due to the failure of chloroplasts, this may be caused by nutritional problems, environmental stress, or old age.

• Corm – A type of underground storage root, found at the base of a stem. Most corms are dense and somewhat woody compared to bulbs, rhizomes, or tubers.

• Crawler – The juvenile, most mobile form of scale insects.

• Crown – A cluster of stems, closely attached to each other just below or above the soil’s surface that emerges from the roots together as a visible tuft or clump.

• Cultivar – A distinct variety of a plant that is propagated vegetatively to preserve its unique or desirable characteristics.

• Deadheading – The removal of aged or dead flowers, which often encourages a plant to produce additional blossoms.

• Deciduous – A plant that sheds its leaves and then grows new ones, usually after a period of dormancy.

• Dish Garden – A single container planted with several different plants.

• Dominant Bud – The bud at the tip of a stem, where most new growth occurs. Removing the dominant buds often causes latent buds, located farther down the stem, to begin growing.

• Dormant – A natural part of a plant’s life cycle when it grows very little, often without benefit of leaves or stems, as do many bulbs, corms, and tubers.

• Double Flowers – Flowers with roughly twice the number of petals present in the single-flowered version of that plant. Double flowers usually have two layers of petals.

• Epiphyte – A plant that lives on another plant, as do some bromeliads, cacti, and orchids that live on tree branches in tropical forests. Epiphytes are not true parasites because they do not take nutrients from the plant on which they live.

• Epsom Salts – Used in very small amounts, this drugstore staple can provide magnesium for selected houseplants.

• Evergreen – A plant that retains its leaves year-round, even when grown outdoors.

• Family – A large group of plants that have botanical similarities, which are further divided into genera.

• Foot-Candle – The amount of light cast by a candle 1 foot away. Low-light indoor plants need 100-300 foot-candles of light. Those that need medium light need 300-600 foot-candles, while high-light plants need a minimum of 700-1200 foot-candles.

• Frond – A type of leaf comprised of finely divided sections, which are characteristic of ferns and some other plants.

• Fungus – A primitive, plantlike organism that lacks chlorophyll and is usually a parasite, drawing nutrients from a host plant or animal.

• Genus – A group of similar plants within a plant family. The first word in a botanical name is the plant’s genus.

• Glochid – A hooked spine present on some cacti.

• Graft – The union where the rooted portion of one plant grows together with the stem or leaf of a different plant. Some cacti, trees, and shrubs are grafted plants.

• Honeydew – the sticky liquid excreted by insect pests that suck juices from houseplants.

• Hybrid – A novel plant developed by crossing different parent plants when they flower, usually by transferring pollen of one parent to the ovary of another. When the seeds mature, the generation grown from those seeds is the hybrid. In houseplants, once a hybrid is created, it is usually propagated vegetatively rather than by seed. Complex hybrids often involve hybrid parents created by crossing different species. These often include an X in the variety name.

• Hydroponics – The practice of growing plants in nutrient-enriched water that is continuously circulated around the plants’ roots.

• Hygrometer – An instrument that measures the amount of water vapor present in the air.

• Isolate – To separate new or pest-ridden plants from other plants by a distance of at least 10 feet.

• Keikis – Small plantlets that develop on the flower stem, close to the parent plant, of certain orchids, including some Phalaenopsis and Dendrobium orchids.

• Latent Bulbs – Growing tips, often not visible, that plants possess along their stems, usual at leaf nodes. The dominant bud, or tip bud, is removed, latent buds begin to grow.

• Lateral – A branch or stem that emerges sideways from another stem. Pinching off a stem tip often leads to the development of lateral branches.

• Latex – A milky sap present in some plants, which often tasted bitter and become sticky as it dries.

• Leaflet – A small leaf that is part of a larger arrangement comprising a compound leaf, as is seen in schefflera.

• Leggy – Term used to describe overly tall or elongated plants. The condition often results when plants are not pruned or are deprived of sufficient light.

• Micronutrients – Nutrients that are needed by plants in very small amounts, such as calcium, iron, magnesium, and copper. Fresh potting soil contains micronutrients, as do some fertilizers. Micronutrient sprays made from seaweed or synthetic substances can be applied to plants to provide micronutrients.

• Monopodial – Term used to describe orchids that grow upright fro a crown, or foot, as do lady’s slippers (Paphiolpedilum) and most moth orchids (Phalaenopsis).

• Node – The place where leaves attach to stems. When cuttings are set to root, new roots usually emerge from the nodes.

• Oedema – A condition caused by low light and overwatering in which leaves and stems rupture, evidenced by weeping of water droplets from leaves, or the appearance of raised bumps or ridges on leaves and stems.

• Offset – A small plant that grows from a new crown while still attached to the parent plant. Offsets receive moisture and nutrients from the parent plant until they develop their own set of roots.

• Orchid Mix – A mixture of coarsely chopped fir bark, redwood bark, and small amounts of peat moss, perlite, or vermiculite, or a similar mix, created especially for orchids.

• Osmunda Post – A moisture-retentive plant support made from the roots of osmunda ferns.

• Ovary – The female part of a flower, often hidden fro view at the base of the petals, where seeds form.

• Peat Moss – Dark brown, acidic, organic matter harvested from peat bogs, which absorbs water well and hosts few plant diseases. Peat moss may be a whole and stringy (sphagnum peat) or milled into a coarse powder.

• Pendant – Growth habit in which flowers or plantlets are produced on stem ends, like jewels at the end of a chain.

• Perennial – A plant that re-grows for 2 years or more after dying back and becoming dormant (or semi-dormant) for several weeks, or sometimes months.

• Perlite – Popcorn-like pieces of chemically inert volcanic rock that are infused with tiny openings as a result of being exposed to high heat. Perlite lightens a potting soil’s texture and improves its ability to hold water and air.

• Petiole – The thickened leaf vein, resembling a stalk that attaches a leaf to the stem. Plants such as African violets, begonias, and peperomias have lone, fleshy petioles.

• Photoperiod – Time period, usually measured in hours, that light is available to a plant. Many plants bloom in response to changes in the photoperiod.

• Photosynthesis – The process plants use to create growth by taking in light energy and combining it with energy from moisture and nutrients.

• Phototropism – The tendency of plants to stretch or turn toward the best source of available light.

• Pinch – Removing new growth from stem tips, usually by pinching it off with one’s fingers. Stem tips also can be trimmed using scissors or pruning shears.

• Pistil – The female part of a flower, which supports the stigma, the organ that receives male pollen.

• Plantlet – A small plant that may grow from a stem, root, or leaf and will grow into a new plant if it is given a suitable environment for developing roots.

• Plug – A term used by plant growers to describe little wedges or thimbles of soil containing very young plantlets that have been raised from seed or tissue culture.

• Pot-Bound – Word used to describe plants in which roots have become so dense within the container that no new root growth can occur.

• Pseudobulb – A swollen stem common in several types of orchids that is used by the plant to store moisture and nutrients.

• Rhizome – A type of storage root that develops from a modified stem, usually with an elongated shape, and often featuring several nodes that can grow into new stems or roots.

• Rooting Powder – Natural or synthetic plant hormones (auxins) that help stimulate the growth of roots in stem cuttings.

• Rosette – A cluster of leaves of similar size that bunch together, often in a circular pattern.

• Runner – A long stem or stolon (surface root) that develops roots and leaf buds to form new plants.

• Seedling – A young plant grown from a germinated seed.

• Spathe – A fleshy bract that is joined to a flower spike, as is seen in anthuriums and spathiphyllums.

• Species – A distinctive form of a plant within a genus. The second word in a botanical name is the species name. If there is a third word, it is called the subspecies.

• Sphagnum Moss – Stringy, un-milled peat moss.

• Spore – A small reproductive structure produced by ferns and fungi, which germinates and grows but does not have stored nutrition or specialized cells typical of seeds.

• Stamen – The male flower part that supports the pollen-bearing anther.

• Standard – A lean, upright plant form comprised of a main stem topped by a mass of foliage, sometimes called tree-form. Standards are pruned and trained plants that may also include grafts.

• Stigma – a female flower part, usually located at the outer end of the pistil that accepts male pollen.

• Stolon – A modified stem that spreads out from the parent plant and has buds capable of growing into new plants.

• Stomata – Pores in plant leaves that “breathe” by exchanging gases.

• Style – The female flower part that attaches the stigma to the ovary.

• Sympodial – Term used to describe the growth habit of some orchids, which develop shallow creeping rhizomes. The tip of the rhizome sends out a green shoot that eventually flowers. Cattleya, Dendrobium, and Oncidium orchids are usually sympodial.

• Systemic Pesticides – Pesticides that are taken up by the plant and spread through its sap and tissues, which are then taken up by insects as they feed. Most (but not all) systemic pesticides should not be used indoors.

• Tissue Culture – A vegetative propagation method in which new plants are grown from a few cells taken from a parent plant. Tissue-cultured plants are sometimes called clones.

• Top-Dress – To replace the topmost layer of the soil in a large container with fresh potting soil. Or, to spread fertilizer, compost, or other substance over the top of the soil above a plant’s roots.

• Topiary – Method of training plants to assume the shape of their support, which is usually a wire form filled with moss.

• Trademarked Plant – A plant with a unique parentage for which a patent has been obtained. Trademarked or patented plants cannot be propagated for sale without permission of the patent holder.

• Tuber – A specialized underground root that stores nutrients and features buds that can grow into new stems and roots.

• Variegated – Foliage in which some of the natural green color has been replaced by other colors, such as white, cream, or red.

• Variety – A distinctive form of a species, which can be a hybrid or simply a form that has unique or remarkable characteristics. In a botanical name, the variety name follows the Latin name, is usually within single quotation marks, and is not italicized.

• Vermiculite – Mica-like material made from naturally occurring mineral deposits that lighten the texture of potting soil and improve its ability to hold water and air.