Judy, Erythronium has bulb, and Polygonatum has rhizome, Calla (Zantedeschia) has tuber, and Ranunculus asiaticus has tuberous root system. Otherwise your summary is correct. Bye, Jan, Z5a, Hungary 2009/12/14 Judy Glattstein <email@example.com>: > Here is the relevant handout material from back when I taught a required > bulb i.d. course for School of Professional Horticulture students at the > New York Botanical Garden: > > Geophytes - definitions > > common point: the ability to store food over adverse conditions. > > bulb: a true bulb is composed of modified leaves called scales. They may > be loose and open (as in lilies) or tight and compact (as in narcissus). > Some bulbs have a thin papery covering, called a tunic, as in tulips. > Roots grow from a basal plate located at the bottom of the bulb. In > autumn true bulbs contain the embryo plant complete with flower buds. > True bulbs form offsets from lateral buds on the basal plate. > Examples: allium, fritillaria, galanthus, lily, narcissus, tulip, scilla > > corm: a corm is a mass of undifferentiated storage tissue derived from > modified stem growth and covered by dry leaf bases. These coverings may > be reticulated (netted) or annulate (ringed). Roots grow from a basal > plate. The growing points on top may be single or multiple. A new corm > is formed each year. > Examples: colchicum, crocus, erythronium, freesia, gladiolus > > tuber: a tuber is a solid mass of stem tissue, like a corm, but lacks > the tunic-like covering and basal plate. Roots and shoots arise from > growing points or eyes scattered over the tuber. > Examples: anemone, caladium, cyclamen, eranthis, ranunculus > > tuberous root: similar in appearance to tubers but composed of root > tissue, not stem tissue. Fibrous roots are produced during the growing > season, and new growth buds arise at the base of the old stem. > Examples: alstromeria, begonia, dahlia, polygonatum > > rhizome: composed of swollen stem tissue, growing laterally at or just > below the surface, generally freely branching. Roots develop on the > lower surface, shoots on the top. > Examples: calla, canna, convallaria, rhizomatous iris > > > _______________________________________________ > pbs mailing list > firstname.lastname@example.org > http://pacificbulbsociety.org/list.php > http://pacificbulbsociety.org/pbswiki/ > -- Protect the enviroment! Please think twice before printing this e-mail. || Védjük környezetünket, csak szükség esetén nyomtasd ki ezt a levelet!