Yes, the tiny offsets are just baby tubers. I'm not familiar with all plant forms since I spend my time trying to understand aroids Corm is just not a useful word when talking about aroids since it does not fit the definition. Certainly, tubers are corm-like but a tuber is different than a corm.
While working on my article my friend and scientist Christopher Rogers wrote the following, "a corm is composed entirely of stem tissue. It is literally just an underground stem. It has an epidermal layer, a vascular cylinder with phloem and xylem and central pith. A corm can also be a starch storage organ, but it still has true stem tissue. This is why a corm has the new foliage growth coming from the top and the roots coming from the base. Corm examples are Crocus, Cyclamen and Gladiolus. A cormel is just a diminutive corm.
A tuber is just parenchyma (with some vascular tissue). It has an epidermal layer with some subdermal vascular tissue, and all the rest is parenchyma. It is almost entirely a starch storage organ. This is why the foliage and the roots all come from the top. Most plants with tubers have them borne on stolons, but that is not necessary. In Amorphophallus, Arum and Typhonium for example, the stem tissue is all encased in the small bud at the top of the tuber. That bud grows upward into a leaf or two, and outward into roots, with the tuber beneath. Other tuber examples are potatoes and Sinningia."
A bulb is composed of thick modified leaves arranged in layers that are used for food storage. An onion is a perfect example. As you can easily understand an onion is not like the tubers that grow from an aroid.
Although many authors use bulb, corm and tuber interchangeably the only term that is truly applicable to an aroid is tuber. Bulb is used far more commonly in horticulture but never in relationship to an aroid, at least by a scientist.
I realize some of Christopher's terms are technical but I'm going to do to all of you what Dr. Croat does to me all the time. He makes me go look up the terms! I would strongly suggest all of you buy a copy of the Oxford Dictionary of Plant Sciences so you can learn what terms like these really mean. It is cheap on Amazon.com
I'll give you a bit of help and tell you the xylem is just a network of hollow cells found in a plant's vascular system that transports water and soluble nutrients collected by the roots. Look up the other words and you'll start learning a bunch more about the plants you love!
Dr. Croat who I consider my mentor followed up with this after reading Christopher's distinctions, "That is an excellent distinction that you made for the difference between tuber and corm. I have always assumed that the corm was non existent in Araceae since most storage organs called stems are just a big bag of starch."
Steve
