Dahlia Classification Abbreviations

One or more rows of petals surrounding a dense group of collared, elongated disc florets.

Fully double flowers, ball-shaped or slightly flattened at the face, the ray florets blunt, rounded, or indented. Involute for most of their length, fully involute for about one-half their length, and normally displayed in a spiral arrangement. (Involute-Florets rolled forward or overlap)

C – Straight Cactus 
Petals rolled for one-half their length, straight or nearly straight.

One row of flat or slightly cupped petals surrounding a disc. These flowers have an inner set of petaloids generally multiple and irregular forming a collar around the disc. (Petaloid-Additional floral parts on the ray florets appearing smaller)

FDFormal Decorative
Flat petals with an even, regular placement throughout the flowers.

IC – Incurved Cactus
Petals rolled for their full length, with tips of the petals curving toward the center of the flower.

IDInformal Decorative
Generally flat petals, sometimes slightly rolled at the tips, but with irregular arrangement of formation.

Petals are split at the tip with the number and depth of the splits varying according to the size of the flower.

MBMiniature Ball
Except for the size, miniature ball and ball dahlias possess the same form features.

MSMignon Single
Single row of petals, with a flower diameter under 2″.

NONovelty Open (Disc) Center
Characteristics distinct and different from the present classification. Center is open.

NXNovelty Double Center
Same features as Novelty Open with a double center.

Open centered flowers with one of ray florets surrounding a disc. The florets involute for two-thirds or more of their length. Usually partially overlapping.

Fully double flowers almost round in shape with tightly quilled petals. Flower size 2″ or less.

Open centered flowers with two or more rows of petals surrounding a disc. Petals may be irregularly formed.

SSingle Single
Single row of flat petals surrounding a disc.

SC Semi-Cactus
Petals flat at the base, with less than half of the petals rolled or quilled.

Decorative shaped flowers with petals being creased causing them to be narrow and involute with a slight recurve to the stem.

Closed center with multiple rows of ray florets normally broad and flat or slightly incurved, depth usually less than one half the diameter.