Questions about seeds from hot and dry summer areas

Jane McGary
Wed, 18 Jun 2003 14:22:43 PDT
Jamie asked,
>you mentioned "tumbleweed" dispertion.  Is this a mechanism used by the
>drumstick Alliums?  It would explain their inflorescenses and the fact that
>they typically free themselves from the bulb before they are ripe.  Perhaps
>to start a journey and release ripe seed while underway?

Yes, that is exactly what the term "tumbleweed" refers to. Many plants from 
dry, open habitats have this characteristic. Lewisia rediviva is a good 
example from the dicot group. Its plants often can be found in colonies in 
the lee of rock outcrops, where the dried capsules are deposited by the 
wind flowing over the outcrop, and where the seedlings find a little extra 
moisture. ("Tumbleweed," by the way, is the American common name for 
Amaranthus albus, an introduced weed.)

Jane McGary
Northwestern Oregon

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