Corms look a lot like bulbs on the outside but they are quite different. They have the same type of protective covering and a basal plate like the bulb does, but do not grow in layers.
Instead, the corm is the actual base for the flower stem and has a solid texture. As the flower grows, the corm actually shrivels as the nutrients are used up. Essentially the corm dies, but it does produce new corms right next to or above the dead corm. It has contractile roots that bring down the corms as they rise up to the surface of the soil which is why the flowers come back year after year. Depending on the type of flower, it may take a couple years to reach blooming size.
A corm does not have visible storage rings when cut in half. This distinguishes it from a true bulb.
Corms of a dormant colocasia (Elephant Ears) and a crocus in bloom.
Many corms produce two different types of roots. Those growing from the bottom of the corm are normal fibrous roots, they are formed as the shoots grow, and are produced from the basal area at the bottom of the corm. The second type of roots are thicker layered roots that form as the new corms are growing, they are called contractile roots and they pull the corm deeper into the soil. They are produced in response to fluctuating soil temperatures and light levels. Once the corm is deep enough within the soil where the temperature is more uniform and there is no light, the contractile roots no longer grow and the corm is no longer pulled deeper into the soil.
The newly dug corms will have cormels that are pea size formed around the top of the old corm. The remains of the old corm will be directly beneath the newly formed corms. When the corm is cleaned up and the old stem removed, the growing point of the corm will be evident. The cormels can be saved and replanted in the back of the garden until they reach flowering size.
Examples of Hardy Corms – Crocus. Arisaema, Crocosmia, Liatris
Examples of Tender Corms: Gladiolus, Colocasia, Alocasia, Bananas (Musa), Ensete, Taro, Xanthosoma
Tunicate bulbs are some of the most familiar bulbs we come in contact with both in and out of our gardens.
Many underground plant structures are generally named bulbs. A definition of a bulb is a plant that incorporates its entire life cycle in an underground storage unit. Technically true bulbs are compressed stems surrounded by fleshy leaves acting as food storage organs. They are in the Monocot family of plants.
Graphite Drawing of Onion and Garlic bulbs
Bulbs can be further classified by looking at their various growth habits. Some of these “bulbs” are actually further classified as “true” bulbs, corms, tubers and rhizomes. Examples of these bulbs respectively are: narcissus, crocus, dahlia and canna.
True bulbs are represented by two classifications, tunicate and imbricate as represented by onions and lilies in that order.
Tunicate bulbs have a dry thin paperlike sheath surrounding them which helps to prevent them from drying and improves their storage capability. The basal base plate along with the tunicate sheath hold the bulb together. Roots emerge at the bottom of the basal plate.
We enjoy these bulbs both in the kitchen and in our gardens. Our cooking is enhanced by the addition of the tunicate bulbs of onions, garlic and shallots. The joyous colors in our early spring gardens are presented by our daffodils, tulips and hyacinths.
The term “bulb” is used by most people to refer to plants that have underground, fleshy storage structures. Only some of the plants commonly called bulbs actually are bulbs. The general definition of a bulb is any plant that stores its complete life cycle in an underground storage structure. These underground storage structures store nutrient reserves to ensure the plants’ survival.
Tubers, rhizomes, corms, and bulbs actually all serve the same purpose, just in a different way. They are each a storage unit for food that gives the plant the energy it needs to grow, bloom and complete its lifecycle each and every year.
The energy is created and stored by the foliage’s photosynthesis. You’ve probably heard that it’s important not to cut back the foliage after the bloom has died. That is because the leaves need to have time to absorb energy for next year’s bloom. Each storage system takes differing amounts of time to perform this task. Examples would be Alliums and Daffodils.
Bulbs or bulb-like plants are usually perennials. They have a period of growth and flowering. This is followed by a period of dormancy where they die back to ground level at the end of each growing season.
As with perennials, there are bulbs that are hardy in our climate and others that must be overwintered as house plants or placed in dormant storage.
Bulbs can be broken down into five types of storage structures. These include: true bulbs, corms, (stem) tubers, tuberous roots and rhizomes.
“Leeks and Pearl Onions” a graphite drawing by the Artist Mary Ahern
Daffodils are classified using two parts of the flower. For the purpose of this description, the daffodil is divided into two regions, the perianth (petals) and corona (cup).
In further classifying daffodils the perianth (petals) is described by identifying first the outside edge of the petal, then the middle, and lastly the inside part next to the corona.
The information I am providing in this article is gleaned from two sources, The American Daffodil Society and Brent and Becky’s Bulbs. Both of these websites offer untold amounts of information and make enjoying the spring displays even more rich.
The Daffodil Society even has downloadable & printable coloring books for those individuals who work with children’s groups. Brent and Becky’s information filled Fall Bulb catalog arrived just in time for Spring so that we can go out to view daffodils in other gardens and make a list for next year’s display.
All daffodils are classified into one of the thirteen divisions described below:
Division 1 – Trumpet
One flower to a stem, corona (trumpet or cup) as long or longer than the perianth segments (petals).Trumpets usually produce larger bulbs than other divisions. Most have gray/green foliage ½” – 1” wide
Division 2 – Large Cup
One flower to a stem, corona (cup) more than one third but less than equal to the length of the perianth segments (petals).The group that you see the most often used in gardens; perfect for perennializing, picking, forcing and showing; some of the showiest daffodils are in this division and are the ones that give you more ‘bang for your landscape buck’.
Division 3 – Short Cup
One flower to a stem, corona (cup) not more than one third the height of the perianth segments (petals).These are long term perennializers, show flowers and late season picked flowers, often with a spicy fragrance.
Division 4 – Double
Daffodils have a clustered cup, petals or both. There can be one or more flowers per stem.Camellia or roselike flowers; with single of multiple blooms; good for shows, showy gardens, picking and bedding.
Division 5 – Triandrus
Usually more than one flower to a stem, head drooping, perianth segments often reflexed and of silky texture.Fuchia-like blooms often with a fruity fragrance; great in containers.
Division 6 – Cyclamineus
One flower to a stem, perianth significantly reflexed and corona straight and narrow. Some exceptions exist.With their faces looking like they are standing in front of a fan, they look & perform wonderfully in pots & are terrific for forcing; seem to be more tolerant to partial shade moisture as a group.
Division 7 – Jonquilla
Usually several flower heads to a stem, flowers usually fragrant, stem is round in cross-section and foliage is often rush like.Foliage is often reed-like or at least very narrow & dark green. Most like the hot baking summer sun. Better in southern gardens but some are adaptable in cooler climates. Sweetly fragrant. Most are great in pots.
Division 8 – Tazetta
Usually three to twenty flowers to a stout stem, sweet scented and very short cupped. Perianth segments rounded and often somewhat crinkled.Excellent perennialzers with a musky, sweet fragrance; good for Southern gardens & forcing.
Division 9 – Poeticus
Usually one flower to a stem. White petals sometimes stained with the corona color at the base, small flat cup edged with red.Excellent perennials with a spicy fragrance, dogwood-like blooms; good for picking.
Division 10 – Bulbocodium Hybrids
Usually one flower to a stem. Perianth segments insignificant compared with Corona.Cultivars in this division are offspring of the species bulbocodium conspicuus, often referred to as ‘Hoop Petticoat’.
Division 11 – Split Corona
Corona split – usually more than half its length.A division where the cup of the daffodil is split into segments & spreads back against the petals. Sometimes the cup is smooth, often it’s frilly & many other times it’s in between.11a) Collar Daffodils Split-corona daffodils with the corona segments opposite the perianth segments; the corona segments usually in two whorls of three11b) Papillon DaffodilsSplit-corona daffodils with the corona segments alternate to the perianth segments; the corona segments usually in a single whorl of sixColoration of the corona often appears in sunburst-like streaks.
Division 12 – Other Cultivars
Daffodils not falling into any of the previous categories.
Division 13 – Species All species and reputedly wild forms.
Ones that are referred to as species daffodils & most of which are Heirloom & suitable for restoration gardening from 1700 on.
All photos are from the Brent and Becky’s 2013 Fall Catalog.
Disclosure: We receive NO financial or other consideration from either of these organizations for linking to their websites.
Brent and Becky’s Bulbs.. Either read their print catalog or view their digital catalog online.
American Daffodil Society. Visit and learn from their information filled website.
Bulbs (which are referred to as “true bulbs”) grow in layers, much like an onion. At the very center of the bulb is a miniature version of the flower itself. It is composed of a shortened stem covered with modified leaves called scales. Helping the bulb to stay together is something called a basal plate, which is a round, flat area that are the beginnings of the roots on the bottom of the bulb.
Many plants such as daffodils form new bulbs around the original bulb. These bulbs, called offsets, develop from buds within the base of the mother bulb and produce new plants. When these bulbs become overcrowded, the flowers start to diminish in size. This is an indication that it is time to dig up and divide the bulbs.
Examples of True Bulbs: Tulips, Daffodils and Alliums commonly known as Onions
After I finished the drawing I cut up the onion and put it in a stir-fry for dinner. Yummy!
TRUE BULBS ANATOMY
The true bulb has five major parts.
BASEL PLATE: bottom of the bulb which hold the bulb together and from which the roots grow
primary storage tissue
skin-like covering that protects the fleshy scales
consisting of developing flower and leaf buds
develop into bulblets or offsets
Grape muscari, otherwise known as Grape Hyacinths live close to the ground. For years I never took much notice of them except for the little spots of brilliant purple that bounced so nicely against the bright yellow daffodils they bloomed along with in April.
Then I got down. Hands and knees down.
What a surprise! How intricate the little flowers are. Little bells dance around a central stem forming a small pyramid. This inflorescence changes shape as it ages and can be more and less tightly knit.
The individual purple doesn’t seem to change on each bell but the overall purple varies when viewed at a distance based upon the tightness of the overall flower.
I enjoyed these 4″ bulbs so much in my garden that I bought a bag of them from Costco one year and low and behold the next spring the flowers that bloomed were very different from my originals. They were more blue than purple and were more rounded than pyramidal.
So I googled Grape Muscari and found a world of cultivars I didn’t previously know existed. That’s one of the things that is so much fun about gardening. You are constantly in a learning mode. You are in for surprises every year and every season. The knowledge and information you acquire just keeps on growing, along with your garden.
So now I know that so far in my garden I have Muscari armeniacum and M. azureaum. Next year I’m sure to have more.
When I made my Digital Mixed Media Painting of my Grape Muscari I was careful to recreate the basal growth of the leaves. It would not have been accurate if I’d placed the leaves higher on the stem. The painting would have looked like a plant Frankenstein. As a Garden Artist, that is not what I’m trying to create.
You can view this Grape Muscari piece in my Store.
© Mary Ahern. Grape Muscari. Prints available in my Art Shop in various sizes on canvas, fine art paper, metal and acrylic.
Sometimes the most fascinating aspect of a flower is before it even arrives. I love to watch the progressive morphing of the Allium bulgaricum as it pushes through the ground early in my perennial bed, usually before I’ve even managed to clean off the winter debris.
These tall, 36″ stalks are very strong and have never needed staking. These particular bulbs have been living in my garden since 2003 after I bought them at an after-season sale at Home Depot. I always scour the sales in various Home Depot stores in my area to capture the treasures left behind by the undiscerning customers.
Allium bulgaricum breaking through the tunicate.
As the flower grows you can see it bulging through the paper thin protective membrane covering.
I walk daily through my perennial bed waiting for the first tear in the parchment like shield. I would liken it to the first beak marks I’ve seen when a chick is breaking out of it’s shell. Not that I’ve seen chicks very often since I was raised in Brooklyn, which is not noted for farmland.
Allium bulgaricum stretching it’s wings
The flowers pounce forth in a gleeful display of empowerment and spread their wings in umbel fashion sitting proudly on tall stalks overlooking a still short, unfolding and early season perennial garden. These are not glamorous flowers in my opinion but they always add weeks of drama to my early spring theater.
Allium bulgaricum in full bloom
Daffodil in my front garden entryway.
I have a number of varieties of White Daffodils growing in my garden but I don’t feel that I ever have enough. Since I am over run by squirrels I try to focus away from crocus and my beloved tulips. (After all, both my parents were born in Holland!) Squirrels consider the bulbs as an entrée and the flowers, if they arrive, as a delectable garnish but they leave my daffodils alone.
The abundant shade in my garden causes challenges to many of my daffodil plantings but I still crave the color in early spring. One of the fun parts of designing gardens is figuring out how to hide the declining leaves on the daffodils as they absorb the chlorophyll for next year’s growth.
I’ve been known to hide them using daylilies, Siberian iris and ornamental grasses. I’ve stopped braiding the leaves since it seems so demeaning to their dignity plus is reduces their exposure to sunlight which helps photosynthesis.
I created a Designer Print from one of these white daffodils. I love the way daffodil leaves have a slight twist to them. One of the things I kept in mind when composing the piece is that the stem is offset where it enters the back of the flower, unlike a tulip which is a straight up vertical.
Another issue is making sure that I paint the shadows different from when the “light” hits the round stem vs. when it hits a flat leaf.
You can see this Single White Daffodil on a Black Background is available in my Shop. in a variety of sizes on canvas, fine art paper, metal and acrylic. I think it has a rather heroic feel to the composition don’t you!
I know I’m suffering from a pretty awful case of cabin fever. So last Friday, January 22 my Hogging buddy, Elisabeth and I spent a wonderful day at the New York Botanical Gardens in the Bronx, NY.
- Snowdrops are put on this planet to bring a smile to your face in winter
- Galanthus elwesii in bloom in the Jane Watson Irwin Perennial Garden, NYBG
Walking through the Jane Watson Irwin Perennial Gardens on the way to the Conservatory, what do we see but the heralding of spring. The Galanthus elwesii and Helleborus niger were in bloom. Right out there, smack in the cold misery of January.
If you need a boost to get you through the next few weeks, seeing these in bloom is just the ticket.
- Hellebore niger were in bloom as were the less showy Hellebore foetidus
- In my own garden I have many cultivars of Hellebore but no Christmas roses
Check your own gardens for what buds are beginning to swell and whether your daffodils are starting to push through the mulch. When I came home from the NYBG I did just that and found a whole host of growth going on right outside my windows.