Lacecap Describes the Unique Flower Structure on Several Hydrangeas
Lacecap Flowers Are the Original Wild Types
Did you know that the wild types of smooth hydrangea, bigleaf hydrangea, climbing hydrangea, and mountain hydrangea (the blue lacecaps pictured above) are not mopheads, rather they are mostly lacecaps in their native forests?
Hydrangea arborescens is the Appalachian-area smooth hydrangea. Hydrangea macrophylla, native to Japan, is the bigleaf hydrangea and Hydrangea serrata is the mountain hydrangea, also native to Japan.
The climbing hydrangea species most commonly grown is Hydrangea anomala subsp. petiolaris and we've only seen it as a lacecap form. If you ever see a mophead version, please let us know so we can get it!
The unique structure of lacecap flowers is the way they attract pollinators and reproduce in the wild.
A Little Botany
Before we explain the lacecap flower, a few terms need to be defined. I am writing these definitions off the top of my head, so if you want textbook definitions, please consult your favorite botanical reference or the on-line Dictionary of Botany.
Inflorescence - A hydrangea flower is also known as a flower head or inflorescence, so I may use these words interchangeably. Then it gets a little more complicated because what we call a hydrangea flower is really a bunch of flowers held together on one head.
Floret - When a flower is complicated like that, each individual flower is called a "floret." A floret is one flower on an inflorescence. Many florets comprise a hydrangea flower.
Sepal - Here's the big surprise: hydrangeas don't have petals. What you see colored pink, blue, or white are called sepals and sepals are . . . modified leaves!
Lacecap Flower Structure
Lacecap hydrangeas are set up by nature to have two kinds of florets in the lacy flower head - fertile and sterile florets.
The showy sterile florets ring the edge of the flower head. They have large, showy sepals because it's their job is to attract pollinating insects to the inner fertile florets. The fertile florets are small, but numerous. The fertile florets don't have sepals because they don't need to be showy.
There are only comparatively few of these showy florets needed to attract pollinators, but the fertile florets are in great quantity to ensure pollination. It's the job of the fertile flowers to make fruit/seeds and reproduce so the species lives on in the woods.
Mophead Flower Structure
The mophead types are, literally, the Garden Variety flower types. They were selected by people to grow in their gardens because they are bigger and therefore there's more mass of color and, in the case of bigleaf hydrangea, more of a spectacle. This whole mophead craze started in Japan hundreds of years ago.
The mopheads are made up of many more showy sterile florets that take up the area fertile florets usually occupy. The showy ones crowd out the fertile florets - to varying degrees in different varieties. For this reason, mophead types attract less pollinators - there simply aren't as many fertile florets to provide insect food.
Balsam smooth hydrangea - see how there are some fertile florets nestled amongst the sterile florets in this mophead?
Mopheads are the Well-known Hydrangea
Mophead hydrangeas are the iconic hydrangea flower, being the most popular in gardens for several hundred years - all the way back to when they were taken out of Japanese forests and planted in nearby gardens.
Mopheads are the flowers of arrangements, pattern design, home decor, and the focus of modern hydrangea breeding. A mophead flower is what you likely picture in your mind when you hear the word hydrangea.
Clearly, Mopheads Have Overshadowed Lacecaps
In our plant booth at the Penny McHenry Hydrangea Festival in Douglasville, Georgia, I was surprised to find people approaching our Irish Lace, Lady in Red, Veitchii, and White Wave plants with a sense of wonder. They had never seen a lacecap before.
It was fun for us to be a part of their plant journeys and to witness their delight in beholding and learning about lacecaps for the first time.
I was personally thrilled because lacecaps have long appealed to me. A modest collection of three white lacecaps were the only bigleaf hydrangeas I planted in my first small garden. Lacecaps are not bodacious, rather they are refined and delicate-looking, having the appeal of an ethereal objet d'art.
More Lacecap Hydrangea Cultivars are Coming
Same as their showier relatives, lacecap flowers come in the classic hydrangea colors of pink, blue, and white with similar variations and permutations to mopheads, such as double florets.
As breeders are developing new plants, they seem to be turning their attention to the lacecaps hydrangeas - finally!
An new lacecap hydrangea with hot pink flower heads is turning human heads. It's called Cherry Explosion and that's a great name for it. It will radiate color in your garden. A neat thing about this new one is that it seems to hold the dark pink very well in different pH levels. We have seen it purple once, it what was likely a highly acidic soil. When purple, it was also color saturated and quite compelling (follow a link to see a pic of the purple).