Any discussion of bulbs and bulb anatomy is hampered by the lack of agreement among those conducting the discussion about what the term bulb really means. For my purposes in what follows, a bulb is a modular mass made up of a growth bud surrounded by fleshy storage tissue, both of these connected to what is often called the basal plate. I’m not going to use the term “basal plate” but instead I’ll call it the “perennial stem” of the plant. With that in mind, bulbs have two sets of stems: the annual stems which emerge from the ground and on which any leaves, flowers and seeds formed by the plant develop. In those bulbs which produce roots from the annual stem (many lilies do this) it helps to distinguish between the annual roots and the perennial roots. The annual roots proliferate in whatever top soil or mulch is present; the perennial roots are often deep delving and in my experience much larger. Now let’s go back to the basic definition of “bulb”, because there is a problem implied in that definition. The definition talks about a single bud surrounded by fleshy storage tissue. But all mature bulbs contain multiple growth buds attached to the perennial stem: these exist in various stages of development and to the extent that they develop with their own surrounding fleshy storage tissue they are potential bulbs. But, because they are still intimately connected to the basal plant of the oldest bud (the one which flowers), they are not modular. They are, so-to-speak, only potential bulbs. At this point, we might start a discussion about whether these are properly called bulbs or something else. Instead, let’s look at it this way: the only time in the life of a bulbous plant when it consists of only one growth bud and surrounding tissue is shortly after germination from seed. Surely the time when additional growth buds are added varies, but the addition of those additional growth buds is one of the most important, urgent things to happen in the life of a bulbous plant. If you follow me here, and accept the above, then it becomes apparent that our definition of bulb has to allow for the fact that bulbs, except in the very earliest phases of their existence, always contain more than one vegetative growth bud. In that sense, the bulb you hold in your hand is a compound structure with the potential over time to develop multiple annual stems as the perennial stem grows and expands. In some bulbs, such as tulips, the bulbs you dig in June are not the bulbs you planted in September. They are new bulbs, most of the matter of the bulb you planted in September has been used by the plant to produce a flowering stem; most but not all. Part of it survives long enough to build the perennial stems of the offset bulbs. The perennial stem of the tulip is the only part which survives from year to year. Imagine an oak tree in winter. At the tip of each branch there is a bud for vegetative growth, protected in the case of the oak by dry, scaly bracts. Now imagine that all of the oak trunk and branch work disappear, all those now detached oak buds are homologous to the bulbs of a tulip clone after many years of growth. In other bulbs, the fleshy scales seem to persist from year to year. Is the resulting mass actually a single bulb? In a sense yes, in a sense no. Yes, because it seems to form a coherent mass – and our common sense certainly urges this usage. But no in another important sense: the bud which began it all has long since disappeared and been replaced by a succession of vegetative growth buds on the perennial stem. Those old, accumulated fleshy scales no longer surround a unique bud, they simply persist with no purpose other than food storage. That’s one reason why we don’t consider them to be a cluster of bulbs: the fleshy scales are there but they do not surround a unique bud for vegetative growth. And of course, the whole mass still looks like a single bulb to us. Now to the Fritillaria question which prompted this email. When we speak of bulbs, we often make a distinction between tunicated bulbs and non-tunicated bulbs. If you give consideration to the origin of the tunic, it becomes apparent that the degree of tunication varies a lot among bulbs. The tunic is what remains of the outermost fleshy scales of the bulb. This is easily seen in the kitchen when you peel an onion, especially one where the outermost scales layers are becoming soft and mushy. In nature, these would dry into the papery layer we call onion skin. Tulips have a heavy tunic, daffodils have a flimsy one. Bulbs which mature under damp conditions are apt to have thin or defective tunics. Bulbs which mature under dry conditions are more apt to have discrete undamaged tunics. Fritillaries are usually placed among the non-tunicated bulbs. However, if you examine newly matured bulbs of Fritillaria imperialis and F. persica, you will usually be able to find patches of tissue thin tunic material. This is more easily seen in F. persica than in F. imperialis, but both species show this. In the culinary onion, you can see that the onion skin is formed when the outermost layers of the onion dry out. Those layers are the scales of the onion bulb. If the sparse tunic material seen on Fritillaria imeprialis and F. persica is formed the same way, then that indicates to me that bulb scales have dried out to form it. So , I’m in the camp which doubts that the scales seen in purchased bulbs continue to grow year after year to form larger and larger scales. However, there are instances of bulbs which do retain large scales indefinitely. In some lilies, such as Lilium superbum, the bulbs produce networks of rhizomes with the newest bulbs at the periphery. The oldest bulbs remain connected to the network, but as far as I know do not sprout again (but they can be broken up and the scales will form new plants). Nor do they increase in size. So, if those big frits are keeping big scales from year to year, they are not the only liliaceous plants to do so. Here’s a challenge for the group: get some nice new bulbs of the big frits and then either stick sterilized pins into the fleshy scales or stain the scales in some way. At digging time the next year, see where the pins or colored scale matter end up: are they still firmly inserted in a scale or part of a healthy bulb, or are they loose in the soil outside the mass of the bulb? That should answer this question about the persistence of big scales in these bulbs. Jim McKenney On Friday, June 6, 2014 7:24 PM, Jane McGary <janemcgary@earthlink.net> wrote: Ian Young certainly knows more about bulbs than I do, but if I happen to lift one of my fritillarias while it is in growth, there is a bulb of the usual size present. Laurence Hill's photos of entire fritillaria plants, in flower, also show the bulbs. I wonder if this characteristic varies among the different subgenera? For instance, subgenus Liliorrhiza (the western American species) may add new scales attached loosely to the basal plate (e.g., Fritillaria biflora and F. striata) or may maintain a slowly enlarging disc-shaped bulb with numerous loosely attached "rice grain" offsets (the F. affinis group). In both cases the bulb is present at any time in the growth cycle. In some other subgenera, I think the bulb may diminish in size during flowering, but it doesn't disappear. Nor do fritillarias produce "dropper" bulbs at the base of the stem as tulips do, although some of the American species such as F. striata will "drop" their hooked scales down early in the plant's life. Perhaps the disconnect between our observations has to do with the distinction between "layers" (as on a Narcissus or Allium) and "scales," as on a Fritillaria or Lilium? It is true that Fritillaria bulbs do not have completely enveloping layers like an onion or many of the amaryllids. I can't defend my position with photos at the moment since all the frits are dormant or nearly so, but I can measure some bulbs this summer and, if I have enough of the species, I'm willing to lift them in flower and see how different the bulb size is, if at all. Jane McGary Portland, Oregon, USA >I quote (Ian Young): > >"Classic bulbs such as Narcissus are perennial adding extra layers >each year all fritillaria bulbs are annuals, replacing themselves >completely each year with a new one that forms at the base of the >growing stem." _______________________________________________ pbs mailing list pbs@lists.ibiblio.org http://pacificbulbsociety.org/list.php http://pacificbulbsociety.org/pbswiki/