You might feel resistant to, or overwhelmed by, technical terminology. I've heard it referred to as Botany Techno-Babble. However, there is no other way to communicate certain ideas, so here is a short, illustrated course, but just for BLOOM words. OK?
REVOLUTE
Cactus Dahlia petals must show Revolution. This means curved away
from the midline of the petal, along its length. Sufficient revolution
will create a tubular petal which may be referred to as Fully
Revolute or Quilled. Semi-cactus Dahlia petals are revolute
for up to half their length. Straight or Incurved cactus types
are revolute for more than half their length. No cactus type is
required to be fully revolute, but it usually occurs, at least
near the tips. Common understanding is that a real cactus must
show quilling, so perhaps it is time to revise the official descriptions
to require some degree of full revolution. Many Decorative
types show a certain amount of revolution
for less than half the length of a typical petal.
INVOLUTE
This means curved towards the midline of the petal, along its
length. Sufficient involution will create a tubular petal which
may be referred to as Fully Involute or Quilled. The Ball
and Pompom Dahlias must have petals that are actually quilled
for at least half their length. The Decorative category has many
permissible characteristics and many Formal
and Informal Decoratives show a lot of Involution, but not fully
involute, especially not near the tips. The Orchid type Dahlias
must show two thirds involution and at least one third fully involute.
There are very few Double Orchids (classed as Novelty types) -
none in current cultivation. Keep tuned, I'm working on it.
REFLEXED
Dahlia petals grow out of a fleshy supporting head that is supposed
to grow and shape itself to carry the older petals at an increasingly
rearward pointing angle. Thus, the petals are said to Reflex.
The ideal for most types is that the petals will reflex back to
touch the stem and form as globular a bloom as possible. This
term is very poorly used, and confused with Recurved in many publications,
including the official ADS Classification book. The next term
is...
RECURVED
A petal is Recurved when it CURVES away from the center of the
face of the bloom. Involute petals and flat petals may show a
recurve. Revolute (Cactus) petals never recurve - I expect it
is genetically impossible. Some Dahlias
recurve so much that the petals overlap at the stem and form a
complete hollow globe.
INCURVED
A petal is Incurved when it CURVES towards the center of the face
of the bloom. Any style of petal may Incurve, but it is desirable
only in a subsection of the Cactus type. The combination of fully
revolute and Incurved petals forms a particularly light and delicate
bloom. It is very difficult for Incurved petals to have sufficient
Reflex to approach the stem and create blooms that are as deep
as they are wide, but some do.
Copyright © 1996 Wayne Holland
email to nospam_hydahlia@shaw.ca just delete the nospam part!
