Hi, All: (1) short stems; (2) slow to moderate rate of increase; (3) attractive flowers; (4), most important, low-lying or sparse foliage that will not look messy as the bulbs mature. I've been pondering this topic for a while, and am not sure I have quite grasped what is being asked. Normally I would start the other way around, meaning if I have a trough, will it have a grit topping/or bark mulch, will it represent some kind of landscape or should it be in glorious flower for a certain period, will it be summer dormant or in flower for a long period of time, will it have winter protection from frost or rain, or won't it, etc. I am assuming this is to be a master list of small (tiny?) bulbs for various uses, and hardy for me with minimal care. If I were to plant a trough, some of the smaller bulbs I'd consider would include: Olysinum (Sisyrinchium) douglasii--especially some of the color varients now becoming available. (sources??) Sisyrinchium macounii album--the nomenclature on this has probably changed, but if there is room for a plant as large as 6-8 inches tall, this is amiable and nice. White is always a good color. Other Sisyrinchium-many are herbaceous perennials, but are petite, and have small scale flowers for a long period. Blue, yellow, white, or? Some of the long season bloomers may set enough seed to be weedy, but we know how to remove weeds. Allium-Ha, bet you can't stop with just one. Choose for foliage interest as well as flowers, to extend the period of interest. A late summer or fall bloomer would be nice to extend the season. Brodia-second Diana's suggestions. I'd add Brodia coronaria. As it grows in my pasture, this is under 6", and is worthwhile because it flowers (blue of course) about the first of July when not a lot is going on. My plants may be depauperate/smaller than some forms. Calochortus--some of the small cat's ears. These deserve close-up inspection to be appreciated. In the garden they really can't be seen. Rather large leaves, but may be glaucous enough to be interesting. Delphineum menziesii-Mary Sue will forgive me for this one, I hope. This gives flowers for a fairly long period, has nice foliage which is different from many bulbous plants, and in the wild as I've seen it, can be under half an inch tall, if there are not too many flowers sticking up. There are other Delphineum, many not geophytes, but small and worthwhile. Dicentra--The small ones I've grown aren't worth growing for flowers, because they go so quickly, but the foliage makes them almost worth growing-- if only it lasted a little longer. I'd look for more small Dicentras. Narcissus-many worthwhile small/tiny ones. I'd probably try N. asturiensis, formerly N. minimus and forever Minimouse. Earlier to start flowering than many narcissus, this is worthwhile as a shock plant--the flower is bigger than the plant, if such a thing is possible. There are many small jonquils, most would be nice. Sun Disc is later than some, and worthwhile for that reason. There are many bulbocodiums, the foliage is small, and in some varieties is also flat on the soil surface, so is not obtrusive. Flowers are usually relatively large, but smaller flowers can be found. I'd like to suggest an anemonee, but haven't grown any small ones. Same with Oxalis. O. adenophylla adds foliage interest when not in flower, but may need winter protection in a trough. Cyclamen get too big after awhile, but might do for a few years, especially as foliage plants. Geranium orientale-tibeticum is probably too big, but there are other tuberous geraniums, some of which are small. I don't grow any, but I'd like to learn about them. Some species gladiolus are very small, almost like crocus, and with reed like foliage. Same with species Freesia, Ixia, etc. I could go on, but it is someone else's turn. Ken Z7 western O-regon