Morphology, or the study of the shapes of plants and their flowers, is fundamental to the study of plants and to their classification. Plants are often grouped or classified according to the shapes of their flowers and plants with similar flowers are usually closely related. For instance, most members of the daisy and sunflower family (Asteraceae) have distinct, easily-recognized, flower shapes as do the parsley and carrot family (Apiaceae) with flowers that look like Queen Anne's lace.
Plant names, both botanical and common, can often give a clue to the flower's shape and sometimes even its color. The botanical name of the common sunflower is Helianthus, from the Greek work for sun (helios) and flower (anthos). Snapdragons are in the genus Antirrhinum, from the Greek word meaning "like a nose or snout." The nasturtium also owes its name to its form; the botanical name, Tropaeolum, comes from tropaion, the Greek word for trophy. The legendary taxonomist Carl Linnaeus thought its flowers and round leaves looked like a classical battlefield trophy made up of the shields and bloodied helmets of the defeated enemy.
There are many botanical terms that serve as a sort of shorthand in describing plants and can help in their correct identification. For example, flowers can be arranged in a cyme, a corymb, or an umbrel (like Queen Anne's lace) depending on how the individual flower stalks arise from the main stem. Learning some of these terms can help you recognize and appreciate the great beauty and variety of flower shapes and provide a new way of looking at your garden.
Shapes create an atmosphere and make a statement in your garden. Form adds texture and depth in any garden design. By incorporating different forms, your eyes will travel from one shape to another, creating a more interesting image. Comparing and contrasting flower shapes can help you discover what makes interesting and exciting combinations apart from flower color. Monochromatic or one-color gardens rely almost entirely on shape to carry the design. Here is a guide to some basic flower forms and how they might be used in your garden.
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Daisies - create a natural meadow look. Coneflower (Echinacea), black-eyed Susan (Rudbeckia), shasta daisy (Leucanthemum), and sunflowers (Helianthus) are all examples. The bolder plants dominate their space; the more slender flowers mix well with others. Different colors and shapes look wonderful in combination. In the NYBG perennial garden, white coneflower (Echinacea) and black-eyed Susan (Rudbeckia) create a simple yet textured combination through continuity of shape and contrast in color. |
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Umbels or flat-headed flowers - The horizontal lines give the eye a quiet resting point. They have a loose, cottage-garden feel and mingle well with other flowers. Yarrow (Achillea) sedum (Sedum) and cherry pie (Heliotropium) are examples. These flowers are the experts in the floral, cocktail party scene - they know how to mingle gracefully with just about anyone. Their broad, flat lines and airy, open texture blend seamlessly with other floral shapes. |
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Panicles or clusters - These plants are bold and make a statement. While this shape mixes and matches with many others, it is bold enough to stand on its own. It creates an elegant feel to any garden. Phlox (Phlox), hydrangea (Hydrangea) and Joe-Pye weed (Eupatorium) are good examples. |
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Plumes - have a graceful, feathery texture with a shape so attractive and fluffy that they can look glamorous on their own or complement both bold and fine textures. Examples are goat's beard (Aruncus), the versatile astible (Astilbe), and the fragrant bugbane (Cimicifuga or Actaea). In the NYBG perennial garden we have them paired with big leaf hydrangeas (Hydrangea macrophylla), where they act as a light contrast, and conversely we have them partnered with Japanese forest grass (Hakonechloa), where they add a bold accent. |
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Globes - this shape can be fun! They stand out and make wonderful focal points or mix well with other plants. Ornamental onions (Alliums), globe thistle (Echinops), spider flower (Cleome) and dahlias (Dahlia) are examples. The larger flowers are so bold that they can be interspersed loosely in a larger perennial bed. |
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Spires or spikes - add height and create vertical accents that act as exclamation point to catch your attention. Red-hot poker (Kniphofia), blazing star (Liatris), Russian sage (Perovskia) and tall salvias (Salvia) are examples. These shapes are very effective when repeated through a perennial border creating a sense of unity and repetition. |
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Trumpets - are the brassy element in any garden design. They are divas, crying out "look at me". Daylilies (Hemerocallis) and lilies (Lilium) are two examples. |
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Bells - often look like little pixie hats. This is a fun and fanciful shape in the garden, with a graceful flare. Campanula (Campanula), fritillaria (Fritillaria) flowering-maples (Abutilon) and some clematis (Clematis) have bell-shaped flowers. |
Gardening with Shape, Line, and Texture by 
