Dear members, I have the uncomfortable feeling that this discussion is proceeding from "First, let us define our terms" rather than "Here is something I don't understand, do our definitions fit?" I don't think that is what was intended. (I wrote this before reading Jim McK's last post, so it says many of the same things in slightly different words) My understanding of seed germination is a little different than much of what has been discussed so far, and hopefully some comments will add to the understanding of this process--and it is a process, not a single event. 1) Germination--occurs not when a seed or root emerges, but when the seed changes from a resting state to an active state--usually after absorbing moisture, and often after certain other changes, which may involve after-ripening of the seed, whether from maturing of the seed, or caused by temperature changes, leaching of inhibitors, exposure to smoke chemicals, etc. In some instances, a seed germinates without ever emerging from the original seed--and when and how leaves and bulb are formed is an afterward-occurring part of the process of plant formation. > If we take the words literally as used for dicots, they simply do not apply > usefully to monocots, it seems to me. By the way, I didn't make up the > definitions cited; they are Ed McRae's in his book, "Lilies." > > What occurs in some plants is that the germinating seed first produces a > plant without involving photosynthesis. First, a bulb, root, or rhizome is > formed underground -- regardless of where the seed was lying. Then, > sometime later, that bulb or rhizome produces a green leaf -- hence a true > leaf, not a cotyledon regardless of what shape the leaf has. 2) The way I read this, a crinum seed which germinates on the seed/ flower stalk, is not a bulb? The same for a seed which falls to the ground, is not covered up, but still forms leaves, roots, and what appears to be a bulb? In neither case is the plantlet underground. Yet, they form leaves, bulbs, and exhibit photosynthesis. Further, it has often been observed in lily seed exposed to light, (such as has been held in a plastic bag of moist media), normally hypogeal germinating seed will proceed to grow without exposure to the normally required cool resting period. Such light-exposed seed grown bulbs may also turn green where exposed to light--with no leaves present, although leaves develop later. These plantlets grown in plastic bags are not--have never been--underground, so are they supposed to be considered epigeal despite how they formed bulbs, roots, leaves? > > A different sort of plant produces a green leaf or cotyledon shortly after > germinating, and probably before the first rudimentary bulb has started to > form. This germination is "photomorphogenic" from almost the beginning of > the process. This first green leaf could maybe be a cotyledon, but I don't > know whether or not it ever is in monocots. 3) This presumably corresponds to what is usually called epigeal or immediate epigeal, lily seed. The term hypocotyl has been used for this "cotyledon", but the definitions I've seen are confusing. Think of an onion seedling. > In Ed McRae's definitions, the epigeal lilies produce a green leaf sometime > during the first season of growth, while the hypogeal lilies produce the > first leaf only after a period of cold dormancy, so in the second season of > growth. > As Jim McK. defined "epigeal germination" and "hypogeal germination" -- > where the seed germinates rather than how -- the terms are trivial and > almost meaningless, 4) Ed McRae was trying to provide advice on how beginners could produce/ propagate lilies. He didn't try to provide all the exceptions to the rules, and there are numerous exceptions. Jan de Graff, Ed McRae's first employer, gave more complex rules, and listed immediate and delayed epigeal germination, immediate and delayed hypogeal germination, then proceeded to list L. brownii australe, L. parryi, and L. speciosum as lilies which normally form bulblets before forming leaves (hypogeal germination), but which without ever taking a rest period or needing exposure to cool temperatures, would proceed to form leaves reasonably prolifically the first growing season. 5) Where a bulb forms may be an accident--above ground or under. How a bulb forms is more diagnostic. Bulbs form in two main ways--either some growth is sent up immediately, or the seed first forms a bulb, then sends up growth. Those lilies which send up a leaf immediately can be recognized because the leaf is narrow and linear. They usually have the seed on the tip of the leaf, and may resemble an onion seedling. Lilies which form a bulb first, then send up leaves, have leaves that are fatter/much broader, not narrow and linear. The seed does not perch on the tip of the first leaf to come up. While some of the lilies in this class require a warm period to form the bulblet, western american lilies require a cool period to form a bulblet, but can germinate, form a bulblet and send up a leaf within about three weeks under the right conditions. This would presumably also fit immediate hypogeal germination. Since it can happen to seeds lying on top of a seedbed, it could also be called epigeal germination, even though a bulblet was formed before a leaf appeared? Am I confused yet? Ken Ken