Give It a Whorl: Exploring the Intricacies of Poly, Double and Multi-Form Daylilies

Posted by @LALAMBCHOP on
What's in a whorl? Would a whorl by any other name be as sweet? There seems to be confusion in the daylily world as to what constitutes polymerous, double and multi-form daylilies. This article will look at each to help you learn to identify them with ease.

We need look no further than the AHS website for much information on this subject. Here you will find the whorl defined as: "One of the layers of modified leaves that make a flower; a complete flower has four whorls: sepals, petals, stamens, and pistil..." What lay persons think of as "petals", the two outside whorls, are called "tepals" collectively. The outermost whorl comprises the sepals. The outside of these is what shows before the bud opens. When the flower blooms it displays the inside of the sepals in the outer ring, or whorl, and the true "petals" in the next layer. Single blooms have sets of threes, three sepals and three petals. The third whorl contains stamen while the fourth and final whorl houses the pistil which has three carpels, or tubes, in the long shaft, or style. The style leads to the ovary which has three sections and if successfully pollinated will create a seed pod with three chambers. Whew! With me so far? Why this is important will become clear in a moment.

Back at the AHS website we learn this about polys: "Polymerous (formerly polytepal) is an adjective used to designate a daylily with more than the normal number of segments in each floral whorl, i.e., more than the normal three sepals (usually four or five) in the outer whorl and more than three petals (usually the same number as sepals) in the inner whorl. Polymerous daylilies have the extra sepals and petals evenly spaced in their respective whorls.

Did you know that the number of stamen correspond to the number of sets of tepals? Look closely at the following images. A single bloom will have three sets of sepals and petals (tepals) with a corresponding stamen for each. A 4x4 polymerous bloom will have four sets of tepals with 8 stamen and a pentamerous poly bloom or 5x5 will have five sets tepals and 10 stamen. Pretty neat, huh?

Blue Racer (Stamile-Pierce, 2011) shows six tepals, six stamen.


Moose Man (Mauck 2008) demonstrates a 4x4 poly bloom with eight tepals and eight stamen.


Moose Man - 5x5 poly blooms with ten tepals and ten stamen for each.


This 5 chambered pod came from a pentamerous bloom.


From the AHS:

"Single flowers consist of two whorls (layers) of perianth segments: the sepals and the petals. A double flower has more than one petal whorl (hose-in-hose double), or a stamen whorl that contains petaloid (petal-like) stamens (peony type double). In the peony type, carpels may also be petaloid. Individual flowers may be a combination of both double types."

Huh? What does all that mean? Let's look at some pictures.

Some double blooms, the hose-in-hose or layered doubles, have extra whorls of petals. They have layer on layer of petals. Here is Ted Petit's INNER SPACE two extra rows of petals:


Peony style doubles have petal like material formed on the stamen whorl. Sometimes the stamen are included in this extra tissue, sometimes not. Here is INNER SPACE again. This time as a peony style double. You can see the anthers attached to the fluffy tissue in the middle.


Sometimes a double bloom will have aspects of both the layered and petaloid styles. Yet another look for INNER SPACE. The outer whorls are layered with peony style tissue in the center. As you can imagine, with stamen being incorporated into the bloom tissue and partially formed anthers, hybridizing with doubles can be a challenge. Note that none of the INNER SPACE blooms offer anthers full of pollen.


The deer that ate ALL of my daylily buds a couple of years ago left this remnant. It was from a double bloom and shows the two outer floral whorls plus bits of the inner petaloid tissue.


Now we know that polys are single blooms with extra tepal(s) on their two floral whorls and doubles are blooms with extra floral whorls or extra petaloid tissue on their stamen whorl. What in the whorl, then, (sorry, I couldn't resist), is a multiform you say? Let us take one last dip into the AHS well of definitions. It defines multiforms thus:

"This term is used where the daylily in question has been registered correctly as exhibiting two or more of the forms spider, unusual form, polymerous, or double.

A spider is a flower with a 4.0:1 or greater petal length to width ratio. An unusual form bloom is one which consistently has 3 petals or 3 sepals that cascade or are crispate or spatulate. So a multiform could be a poly double, an UF double, a poly spider, an UF poly, etc.

My INEZ MORGAN ECHERD is an UF cascade.


Like it's sibling above, GET OFF MY TUTU has sepals that cascade but it's also a double which makes it a multiform.


Since it frequently throws poly blooms, under today's standards, David Kirchoff could have registred SCHNICKEL FRITZ as a multiform poly double,


and Don Her could have registered STAR POLY as an UF (crispate) poly.


Part of the confusion about these various forms stems from grouping of polymerous and double daylilies in the same class for AHS daylily shows. Hopefully polys will have their own class soon as they are clearly not the same as doubles.

Thanks for sticking with me to the end. I hope the article has helped to expand your understanding in the whorl of daylilies!

Leslie (Lalambchop) Mauck

All photos were taken by the author and may be used if credit is given.

Comments and discussion:
Thread Title Last Reply Replies
very elucidating by Dragonkeep Mar 14, 2017 8:56 PM 0
great job by tink3472 Aug 2, 2014 6:46 PM 9
Can you help me with this one? by blue23rose Oct 12, 2012 2:49 PM 2

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