Mum flowers, or chrysanthemums, were first cultivated in China and are widely recognized as the main flowers of autumn. Many different kinds of mum flowers exist, with a wide variety of flower colors, shapes and sizes. Some mums can resemble dahlias, while others look like daisies. Chrysanthemums are divided into 13 different classes or categories based on their flower characteristics.
Regular Incurve, Irregular Incurve and Intermediate Incurve
Regular incurve chrysanthemums have globe-shaped blooms that are equal in height and width, with smoothly inward-curving petals that form a ball-like flower. Irregular incurve mums have similarly-formed petals, but the lower or outer petals are more irregular and create a "skirt" around the bloom. Intermediate incurve mums have shorter petals than the irregular incurve types and only partially filled-in centers, creating a more open effect. Regular incurve mums have 4 to 6-inch-wide blooms and intermediate incurves have 6-inch-wide blooms, while irregular incurves have larger, 6 to 8-inch blooms.
Reflex mums have downward-curving, overlapping petals. The 4 to 6-inch-wide blooms are globe-shaped but have slightly flattened tops.
Decorative mums have flattened flowers with short petals and no visible central disk. These mum flowers are 5 inches wide or larger. Decorative chrysanthemums have upper petals that curve slightly inward and lower petals that curve downward.
Pompon mums have small, 1 to 4-inch-wide blooms that are globe-shaped but start out slightly flattened when young. The pompon mum's petals curve inward and outward or downward, hiding the central disk.
Single or Semi-Double, Spoon and Anemone
Single or semi-double mums have prominent central disks surrounded by one or more rings of petals, usually resembling a daisy. These mums grow to 4 inches in diameter or larger. Spoon chrysanthemums resemble single or semi-double mums, but their flowers have spoon-shaped petal tips. Anemone mums are somewhat similar to single or semi-double mums, but they have a cushion-like, raised central disk, making them look less daisy-like.
Spider and Quill
Spider mums are 6 inches wide or larger and have long, tube-shaped petals that often hook or coil at the tips, resembling spider legs. Quill mums are similar in size and also have tube-shaped petals, but they are straight with open tips. Quill chrysanthemums have fully-double blooms with no visible central disk.
Brush or Thistle
Thistle or brush chrysanthemums also have tubular petals, but they grow parallel to the stem and are fine. The petals can look like a paint brush or can be drooping, flattened and twisted. These mum flowers grow to less than 2 inches in diameter.
Unclassified chrysanthemums are usually 6-inches wide or larger, exotic and display characteristics of several mum classes. These mums also often have twisted flower petals.