by Grandpa Cliff     Oct 20, 2005



This webpage is not a true glossary.  It usually gives descriptions or explanations instead of technical definitions, and the terms are not arranged alphabetically.  They are grouped together so that similar terms can be compared with each other.  You can scan down the page or use Edit/Find to look for a word on this webpage.  Many plant terms are described on this website in a webpage that discusses that subject.




ORGANISM  - an individual of any kind of living thing


SCIENTIFIC NAME  - all living things have a name that has two parts, both of which are usually Latin words

    Genus    - the first part of the scientific name.  It is always capitalized, and it applies to a group of similar species.

                     Maples are a group of similar species.  Acer is the genus of all Maples.

    Species  - the second part of the scientific name.  The species always begins with a small letter unless it is a

                     proper name, in which case it must be capitalized.  The species name for Red Maple is rubrum.  

[The scientific name for Red Maple is Acer rubrum.  For man it is Homo sapiens.  For the cat it is Felis domesticus.]


BIOLOGY - the study of all living things  [Biological is the adjective form of this word.]


BOTANY - the study of plants  [Botanical is the adjective form of this word.]


ORNAMENTAL PLANT  - a plant grown in parks and around homes for its beauty or as a landscape plant. 



    Woody           - have hard stems made of wood (xylem, ZIGH-lem).  The stems grow for more than one year.

    Herbaceous  (her-BAY-shus)  - have soft stems that usually die in Northern U.S. by the time Winter arrives or

                             shortly after that



    Annual  - lives one growing season.  It must produce seeds so that future plants of that kind can grow.

    Biennial  - lives two growing seasons.  The first year it stores food.  The second year it produces the flowers and


    Perennial  - lives and grows for more than two years (like trees).  Once it matures, it may produce flowers and

                        seeds yearly.



    Evergreen   - keeps its leaves or needles all winter.  They may not fall off for many years (Pine, Rhododendron).

    Deciduous  (dee-SID-yoo-us)  - drops its leaves each Autumn in Northern U.S., and then grows new ones the

                          following Spring



    Conifers  - the seeds are found in cones  (Pine, Spruce, Fir, Hemlock, Yew, Tamarack/Larch, Cedar, Juniper)

    Softwoods    - trees with needles.  Softwoods are Conifers and are almost always evergreen

    Hardwoods  - trees with broad leaves  

        [Oak, Cherry and Maple have broad leaves.  They have harder wood than Pine which has needles.  Oak,

         Cherry, and Maple do not scratch as easily as Pine when they are made into furniture, so Pine is not used in 

         the better furniture.  Ash is a hard wood used to make baseball bats.  Pine is the common wood used to make

         houses.   Nobody cares if the boards in the walls have scratches or dents.  Some "hardwoods" such as poplar

         are actually softer than softwoods.]



    Tree    - has one trunk; grows tall

    Bush    - often has several main stems or trunks; stays short, usually under 10 feet.


PARTS OF A PLANT (and what the parts do for the plant)

    Flowers  - make seeds from which new plants of that kind will grow
    Roots  - take water and minerals from the soil.  Water and minerals are needed by all living cells in a plant

    Leaves  - use water and carbon dioxide to make sugar and oxygen to keep the plant alive

    Stems  - carry water to the leaves, and carry sugar and oxygen from the leaves to the living parts of the plant

                     that need it






1)  Bark          -  the outside layer of a tree trunk or branch. 

2)  Cambium   -  a thin layer between the sapwood and the bark; it causes the growth of a new outer ring of 

                            sapwood to grow each year.  It also adds a new layer to the inner part of the bark each year.  

                            Its technical name is the Vascular Cambium (to distinguish it from the Cork Cambium).

3)  Wood

     a)  Heartwood   -  found at the center of a trunk or large branches.  It often has a dark color.  Many branches, 

               especially the smaller ones, do not have any heartwood.  The heartwood is dead wood.  Wood is made of

               xylem (ZIGH-lem) cells.

     b)  Sapwood   -  the live, outer part of the wood.  The sap moves upward through it.  Sap is mostly water and

               minerals that the roots have taken out of the soil.   All of the wood in small or medium-sized branches is

               sapwood.  As branches get thicker, the center part may become heartwood.  Heartwood and sapwood are

               both made of xylem (ZIGH-lem) cells.

     c)  Pith   -  located at the center of a stem during the first year of growth.  It does not grow any larger after the

               first year.  It is not always visible in older wood.  It is the light center and first dark ring of the next diagram.



    Trunk  - the main stem of a tree or shrub; the stem part that attaches to the roots

    Branch  - a stem that connects to the trunk or another branch

    Branchlet  - the smallest branches on a woody plant

    Twig  - a branchlet.  Best studied without its leaves, as in the Winter or after the branchlet has died.  



    Node  - where a leaf attaches to a stem, the node is the area all the way around the stem at that point.

    Internode  - the portion of stem between two nodes ["inter" means between]


    Blade    - the flat green part that makes up most of the leaf.  Chlorophyll gives the leaf its green color.
(PET-ee-ole)  - the narrow part that connects the blade to the stem of the plant
    Midrib  - the major vein that connects the petiole to the tip of the leaf.  It carries food and oxygen (made in the

                        leaf cells) to the petiole, which takes it to the stem.  It also carries water from the stem to the cells.

    Veins    - the structures that connect the midrib to the edges of the leaf





BUD (on a woody stem)  - it is a bump that is covered with bud scales.  

1)  From a bud can grow leaves, flowers, and new stem cells.  If a bud is at the tip of the branch, when the bud cells grow the branch will get longer.  Buds on the side of a branch cause side branches to form.

        a)  Terminal Bud  - bud at the tip of a stem

        b)  Lateral Bud  - bud on the side of a stem
2)  When the bud scales fall off, they leave bud-scale scars (little grooves that look like lines around the stem) that show where they were attached.  


    Simple         - a leaf with only one blade
    Compound  - a leaf with many blades

        a)  Leaflet - the part of a compound leaf that looks like a regular leaf.

        b)  A leaf will have a bud at the base of the petiole, although the bud will not be easy to see in the Spring 

                 before it has had time to grow.

    Alternate  - only one leaf comes out at a place on the stem
    Opposite   - two leaves come out of the stem on opposite sides of it
    Whorled    - three or more leaves come out of a place on the stem.  Not common. 

    Parallel  - veins go from the bottom of the leaf to the tip; they are all beside each other  (Grass, Tulip, Lily)
    Pinnate  - the veins go from the single midrib to the edge of the leaf  (most leaves)
    Palmate  - there are 3-5 main veins instead of a single midrib; they all start at the petiole  (Maple, Sycamore)

EDGE OF LEAF  (there are many edge terms, but I included only a few here)
    Serrated  -  has small teeth along the edge (like on a serrated knife)
    Lobed      -  a lobe is the part of the blade between two deep cuts in the leaf blade.  ( Oaks & Maples)
    Entire      -  smooth edge; no teeth


PARTS OF A PLANT (see diagram)


Tomato Plant with compound leaves.

A tomato is a fruit even though it is not sweet.



FRUIT  - You know that apples, plums, and oranges are fruits.  Did you know that tomatoes, pumpkins, zucchini, green beans, peppers and cucumbers were also fruits?  A fruit is the part of a flowering plant that contains the seeds.  [Conifers are not considered to be flowering plants, so their cones are not called fruits.]


FLOWER  - Some kinds of flowering plants have the male and female reproductive parts in separate flowers.  Many flowers contain both sexes, as in the diagram below.  The pistil is the female part; the stamen is the male part.  A flower is the reproductive part of a plant from which a seed-bearing fruit develops.





    Chlorophyll  (CHLOR-o-fil) is the green chemical in leaves, some stems, and even the green parts of some flowers.  


    Photo means light.  Synthesis means "to make".  Therefore, Photosynthesis means to make using light.  During daylight, chlorophyll takes the water that comes from the roots, and combines it with the carbon dioxide which comes into the leaf through tiny holes (stomata) on the bottom surface.  The water and CO2 are used to make sugar and oxygen.  Sugar is a food for the plant just like it is for people.  Sugar contains energy that living things need.




Links to other Glossaries

   Gardening Glossary

   Ranger Rosie's Glossary  (ecology, plants, animals)

   Gardening Terms  


Other Gardening Links


   Record-sized Vegetables



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