• Genus: A genus refers to a group of species of plants that share certain structural characteristics as determined by botanical study. The genus name, a noun, may come from mythology, literature, or other sources which refer to something the plant resembles.
• Species epithet: The species, an adjective, often refers to a place, the plant's characteristics/appearance, or the name of the person credited with discovering it . Species are botanically classified by analysis of the flower parts and characteristics for flowering plants, and by the seed/cone for coniferous and other non-flowering plants. This is why plants with distinctively different foliage or other characteristics can be classified as the same species. Species is abbreviated sp. or spp.
• Population:  A collection of plants within a larger grouping that can be distinguished from other members of the larger grouping.
• Variety: A subdivision of species which describes naturally occurring changes, sports, or mutations that create a distinctively different plant in appearance. The same plant may grow on two different continents but grow taller on one than the other or have identical flowers forms but different colors. These would would be an example of different forms or varieties. The key words are "naturally occurring". Those that reproduce the different characteristic without human intervention are named true varieties (var.) or forms (forma) and breed true. Those varieties that require human intervention (asexual reproduction methods), are known as cultivated varieties or "cultivars" for short. These are sometimes abbreviated cv.
• Cultivar: A subdivision of a variety/species that identifies a plant characteristic which originated in nature but can only be replicated by asexual reproduction and human intervention. Examples are variegations, growth forms, foliage or flower color, etc.
• Hybrid: A new variety of plant that is created through human intervention through sexual means (crossing the pollen of one plant with the egg, contained in the pistol, of another which results in a distinctively new plant. Continued reproduction may require the same crossing technique as rarely do seed produced from a mature plant created by hybridization or from a cultivar reproduce the same desired characteristic. Hybrid crosses are readily done among plants of the same species and rarely between plants of different genera.
• Strain:  A population within a species whose members have a different distinguishing trait, but that trait doesn't breed true.
• Mutation: A plant whose genetic information has been altered sometimes changing the observable characteristic of a plant.
• Clone:  A population of genetically identical plants.  Clones can only be produced by vegetative reproduction.
• How to correctly write plant names: When the genus and species are written together, the first letter of the noun genus is capitalized and the species is in all lower case but both are italicized. Latinized names have genders which are expressed in the last syllable. Masculine ends in "us". Feminine endings are "a" and "es". Neuter endings include "um", "n", and "ma". The species, an adjective, must agree with the gender of the noun genus. A cultivar is indicated by a single quote (') before and after the name which is not italicized. If the cultivar is named after someone or a place which is normally capitalized, the cultivar name is also capitalized. Some examples using Hollies follow:


-Ilex vomitoria (the botanical name for Yaupon Holly - this species was used by the indians to induce vomiting - the derivation of it's species name)
-Ilex vomitoria 'nana' (A dwarf form of Yaupon Holly)
-Ilex vomitoria 'Will Fleming' (A cultivar discovered by Will Fleming)
-Ilex X attenuata 'sunny foster' (a cultivar of a hybrid between I. opaca and I. Cassine which produces yellow leaves on new growth)

• Aurea, aureo -- golden (applies to yellow variegations or coloration)
• Alba, albo -- white (applies to white variegations)
• Glauca -- blue (describes a blue tinted leaf coloration)
• Glabra -- shiny, silvery (describes a leaf coloration)
• Rubra -- red (describes red colorations)
• Purpurea, atropurpurea -- purple, (describes purple coloration)
• Marginata -- marginal (describes a type of variegation)
• Medio -- middle (describes a type of variegation)
• Striata -- streaks (describes a type of variegation)
• variegata -- variegated (not specifically descriptive of the type of variegation)
• Contorta, tortulosa, monstrosa -- contorted, twisted, fused growth habits
• Zebrina, zebrinus -- striped or banded
• Tricolor -- a three color blend of variegation
• Rotunda, rotundifolia -- round shaped
• Fastigiata -- tall, slender, upright, columnar shape
• Prostrata -- low to the ground, creeping
• Pendula -- weeping growth habit
• Triangularis, obovatus, lanceolata, serrata, palmatum, etc. -- descriptions of leaf shapes which can be found in glossaries of our book recommendations. In addition, there are standard terminologies for branching forms, leaf types, inflorescence, etc. contained in these glossaries Often these are used in species or cultivar names to describe the unique plant characteristic. Take time to become familiar with them.

In addition to Botanical names, there are botanical terms to confuse you.  Although we don't intend to provide an internet glossary of terminology on horticulture,  one area of confusion in terminology is the definitions of various specialized underground roots containing food storage systems to sustain them through dormancy periods.  These include  many common garden perennials that we grow .  Let's become botanically correct by differentiating these types of plants.

BULBS:  A bulb is like a seed inasmuch as a new plant generates from the embryo contained within (all the plant structures and nutrient for growth waiting to emerge when conditions are right).  Most bulbs are round, contain a thin scaly covering.  A pointed end should always be pointing upward for stems to emerge and the other end develops new roots for the maturing plant.  (Examples: Amaryllis, Crinum, Lilies, and  Onions)

CORMS:  These are flattened swollen underground stems, the tops of which are generally flat.   Corms have scale-like leaves that protect the dormant plant but do not store food.  (Examples: Gladiolus, Freesias)

RHIZOMES:  These are swollen horizontal underground stems with roots.  They can be most any shape, slender or thick, all of which have buds on the growing end.  (Examples:  Canna, Calla, Iris, and carrots!)

TUBERS:  Thick, often lumpy structures that are fatter and shorter than rhizomes and contain growing buds on the surface in non-specific locations.  (Examples:  Caladium, cyclamen, dahlia, and yes, potatoes!)

TUBUROUS ROOTS:  Thick root sections sometimes held in clusters from which new plants can generate from a single root structure.  (Examples:  Agapanthus, Daylily, Manihot)