2014 ADS Classification and
Handbook of Dahlias


Glossary of Terms

BLEND
Two or more evenly merging harmonious or pleasingly contrasting colors.
CENTRAL RAYS
The short or immature ray florets comprising the central portion of the fully double flowers when at their prime stage.
DISC
A more or less flat, circular group of tubular florets fully visible in open-centered type dahlias.
DISC FLORETS
Small tubular florets which make up the central part of the flower head, each with a pistil and stamens but generally no other conspicuous flower parts.
DWARF
Dahlia varieties that normally do not produce plant growth over 24 inches in height.
FLORET
One of the small flowers that collectively comprise the flower head.
FULLY DOUBLE
Flower heads with multiple rows of ray florets; the disc florets are immature and completely covered by the central rays when a bloom is at the prime stage.
INCURVED
The ray florets curve forward along their length toward the face of the flower head.
INVOLUTE
Margins of the ray florets roll forward along their longitudinal axis (length). When fully involute the margins touch or overlap so only the reverse of the floret is visible.
LACINIATED
The ray florets are split; there should be a twisting in the area of the split involute or revolute ray florets, to give an overall fringed effect.
MARGIN
The edge of the ray floret, sometimes marked with a narrow contrasting color
MARGINAL RAYS
: Fully developed ray florets that establish and determine the maximum diameter of a bloom; mature florets rather than immature central ray florets.
PETAL
The common name for the conspicuously colored part of a ray floret.
PETALOIDS
Additional floral parts on ray florets having the form and appearance of smaller petals. Most noticeable in the collarette dahlias.
RAY FLORET
One of the broad, conspicuously colored florets, the structure of which suggests a single petal of an ordinary bloom. These form the radiating border in the open-centered type dahlias, or massed together, the flower head in fully double types.
RECURVED
The ray florets curve backward along their length toward the stem.
REFLEXED
A straight ray floret from the tip to the base that extends and drops toward the stem.
REVOLUTE
Margins of the ray florets roll backward along their longitudinal axis. When fully revolute, the margins touch or overlap.
STRAIGHT
The ray florets have little or no curvature throughout their length.


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