Margeurite, as far as I know, shrub is not a scientific term, rather a gardening term that has worked its way into general use. For myself, a shrub must have a permanent set of woody stems and branches that continue into growth each season. Some shrubs are very large, such as some Magnolia, while others are quite small, as we find in Rhododenron. In my garden Phygelius is a small shrub reaching about 2 meters. Yucca is not woody, therefore I wouldn't call any of its relatives shrubs. Some people may argue this, but the stems of woody plants and succulents are structurally quite different. The term sub-shrub is bantered about without real definition, imo. I have imagined it as a small shrub-like perennial, such as Thymus or Salvia have, that is too ephemeral to truly overwinter/rest. We may place Penstemon in this category, as well. They do form shrubs, but they do not last. If not for their rootstock, they would not survive. What I see as true shrubs, if the entire top was removed (not simply cut back hard), the root stock would probably not recover. For me this is a practical division, but I doubt sound enough for scientific definition. Using this definition, I would consider Fuchsia a shrub, but perhaps not in all species and all climates. Hope this helps. It is really just another educated opinion. Jamie V. Cologne Germany Zone 8 Marguerite English schrieb: > I have been doing some studying about garden terms and have a botanical > question. I was looking at Phygelius information and it was identified > as a shrub. I had previously called it a perennial. So what > differentiates a shrub from other perennials? I noticed some authors > by-pass this problem by calling certain plants "sub-shrubs." And how > does something like Yucca or Hesperaloe fit in? Are they shrubs also, > even though they are succulent? > > Thanks for considering this... Marguerite, still growing > mostly Iridaceae and Zephyranthes, and developing a new cottage-like > garden for my local arid, dry and windy planting conditions at 3700 feet > in southern California mountains. > _______________________________________________ > pbs mailing list > pbs@lists.ibiblio.org > http://www.pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > > >