University of Vermont Extension 
Department of Plant and Soil Science

Anytime News Article

Flower Word Power

By Dr. Leonard Perry, Extension Professor
University of Vermont

When it comes to identifying wildflowers, or even reading about new garden flowers, knowing the words you'll invariably run across will help you feel less lost.

The main method for differentiating plants is by their flowers. This can be from traits of individual flowers, or the arrangement of many flowers into a group called an "inflorescence."

Most garden flowers have male and female parts in the same flower, or in separate flowers on the same plant. These are termed "monoecious," from the words for "one house." If plants have male and female flowers on separate plants, such as in hops, they are termed "dioecious."

If all the floral parts, male and female, are in the same flower, this flower is said to be "complete." Obviously then, "incomplete" flowers have some parts missing. The parts aren't really missing, however; they may just be separated into male "staminate" (has the stamens or male floral organs with the pollen) and female "pistillate" (has the pistil or female floral organ) flowers.

So far, the terms have covered the usually non-showy flower parts. The petals are usually the showy, colored structures familiar to most people. These were designed not for our enjoyment, rather to attract various pollinating creatures that see various colors. The petals are the inner flower parts, and collectively are termed the "corolla."

The outer flower parts, termed the "calyx," are composed of the "sepals." These may resemble petals and are sometimes so similar that they are confused with them. More often, though, they are leafy and non-showy. These may be the parts covering and protecting flower buds before they open.

When flowers are grouped together, into an "inflorescence," they may occur at the end of stems ("determinate") or all along the stems ("indeterminate"). These terms are often used with the tomato, referring to where the fruit is produced.

If flowers occur evenly spaced around a stem, the inflorescence is said to be regular or "symmetrical," as in Garden Phlox (Phlox paniculata). "Asymmetric" inflorescences have flowers on one side of the stem, as in Solomon's Seal (Polygonatum).

Now for the terms you'll encounter most often, sometimes even in the plant species names. These refer to the particular shape of the inflorescence. A "spike" has flowers attached directly to a stalk or stem as in the Spiked Blazing Star (Liatris spicata) or the Speedwell (Veronica spicata).

A "raceme" is often found in gardens with flowers attached to a main stalk by means of smaller stalks ("pedicels"). The Black Snakeroot (Cimicifuga racemosa) and loosestrifes are examples of racemes. Then, if the raceme is branched, it forms a panicle as in the phlox above. If the panicle is flat-topped or convex as in Joe-Pye Weed (Eupatorium) or yarrows, it is called a "corymb." Finally, if the panicle is coiled as in lungworts, it is called a "cyme."

If the flowers are on the short stalks (pedicels) arising from a single point, they form an "umbel." This is common to members of the Carrot Family (formerly called "Umbelliferae"), such as Dill, Fennel and Queen Anne's Lace. An umbel, only with no flower stalks, is called a flower "head" or "capitulum." The dense whorls of flowers on Bee Balm (Monarda) form flower heads.

A "composite flower" is a flower head with two flower types. This is common to members of the daisy family such as sunflowers and asters. What most people consider a daisy flower is actually a flower head. The showy outer parts of a daisy are not petals, but rather ray flowers. The inner, usually yellow, tight part of a daisy is actually many disc flowers.

So, the next time you are in your garden, look at the flowers, and see if they fit any of these descriptions. And when reading garden books and flower descriptions, and you see one of these words, pat yourself on the back for knowing what it means.

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