Glossary of Botanical Terms

In the inventory many botanical terms are used to describe the plants, many of which are the very same terms botanists use to describe and identify plants in the wild. It is therefore understandable that in order to acquire a good design sense, it is very helpful to learn and understand many of these terms, particularly those that are used to describe the morphology of the inflorescence. Most of these have been gleaned from Newcomb’s Wildflower Guide, by Lawrence Newcomb. For a great guide to understanding plant structure from a designer’s perspective see Designing With Plants, by Piet Oudolf.

B

basal: situated at the base of the stem.
biennial: a plant that completes its life cycle in two years and then dies, i.e Digitalis sp.
bract: a very small or modified leaf, usually growing at the base of a flower or flower cluster.

C

corymb: a flat-topped or convex branched flower cluster in which the branching is typically alternate, i.e. Yarrow sp.
calyx: the outer circle of flower parts, made up of sepals.
cespitose (grass): “bunch grasses”; tend to form very tight clumps, which tend not to increase once they have reached a certain size, forming a tussock. They have a distinct shape: narrow at the base with leaves arching out, i.e. Deschampsia, Molinia, Sporobolus.
cultivar: a plant selected for desirable characteristics that can be maintained by propagation. Most cultivars have arisen in cultivation, but a few are special selections from the wild.

F

family: a group of related plants. Families are divided into genera, which are further divided into species, i.e. Apiaceae, Asteraceae, Ranunculaceae, Saxifragaceae, etc.

G

genus: (plural: genera): a group of closely related species. The genus is designated by the first word in the Latin scientific name of a species and is always capitalized, i.e. Angelica, Echinacea, Clematis, Darmera, etc.
glaucous (leaf): light bluish-gray or bluish-white, i.e. Panicum ‘Northwind’.

H

hybrid: any offspring resulting from the cross between parents of different species, often they are sterile (do not produce) seed) i.e. Agastache ‘Blue Fortune’, Aster ‘Twilight’.

I

inflorescence: the flowering part of the plant.
involucre: a circle of bracts below a flower or flower cluster.
irregular (flower): are not radially symmetrical; that is, their petals or petal-like parts are not similar in size, shape, or color. Usually, these flowers have upper and lower parts that are called lips, i.e. Lobelia, Legumes, Violets.

L

lance-shaped (leaf): broader toward one end and tapering to the other, like a lance.
lip: the upper or lower part of many irregular flowers.
lobe: one of the segments, usually rounded, of a leaf or flower, i.e. Lobelia.

M

mat (grass): spread steadily, but often slowly, to form a dense mat, i.e. Carex, Sesleria.
morphology: the study of the form and structure of animals and plants

O

oblong (leaf): longer than broad with parallel sides.
opposite: arranged in pairs on the stem
ovate (leaf): broader end at the base tapering to a point; egg-shaped.

P

palmate: with the leaflets radiating from a central point, like the fingers of a hand, i.e. Kirengeshoma palmata.
panicle: an elongated branched flower cluster, i.e. Aster, Goldenrod, etc.
pendulous: hanging down loosely, i.e. Briza media, Bromus ciliata, etc.
phenotype: the composite of an organism’s observable characteristics or traits.
pinnate (leaf): divided in such a way that the leaflets are arranged on both sides of a common stalk, like the pinnae of a feather, i.e. Sanguisorba sp.

R

raceme: an elongated flower cluster with stalked flowers arranged along a central stem, i.e. Baptisia.
ray: (1) one of the stalks of an umbel; (2) in members of the Composite (Asteraceae) Family, the strap-like or petal-like flowers encircling the disk flowers; part of radially symmetrical flowers i.e. Aster, Echinacea, Solidago.
rosette: a circular cluster of leaves, usually at the base of a plant.
regular (flower): radially symmetrical, which means their petals or petal-like parts are arranged around the center like the spokes of a wheel, i.e. Aster, Echinacea, Solidago.

S

species: a distinct kind of plant. Each species has a two-word scientific Latin name, of which the first word designates the genus and the second word the species, i.e. Angelica gigas, Echinacea purpurea, Clematis integrifolia, Darmera peltata, etc.
spike: an elongated flower cluster with stalk-less flowers arranged along a central stem, i.e. Veronicastrum, Veronica.

T

terminal: at the end of a stem or branch.
toothed (leaf): have several to many small indentations along the margin.

U

umbel: a flower cluster in which all the flower stalks radiate from the same point, like the ribs of an umbrella, i.e. Angelica, Zizia, etc.

W

whorled: wreathed; arranged in a circle around a central point, i.e. Phlomis, Monarda (flower), Veronicastrum (leaf).

Bookmark: The Glossary of Terms