Heterotrophic Plants?

[Wayne Hughes]

In article <199610221307.GAA18926 at net.bio.net> mvanier at GAES.GRIFFIN.PEACHNET.EDU (Marc van Iersel) writes:
>The only heterotrophic higher plant that I am aware of is Indian pipe
>(Monotropa uniflora).  It has no chlorophyll and can no not photosynthesize.
>Their root systems have mycorrhizal fungi that are also associated with
>other, photosynthesizing plants.  These fungi transfer sugars from the other
>plant to the Indian pipe.  I am not sure, but it is possible that Indian
>pipe also uses decaying organic matter as a food source.
>

  There's also coral roots, Corallorhiza, in the Orchidaceae;
  the more directly parasitic dodder, Cuscuta, in the Cuscutaceae;
  and in the Orobanchaceae there's squaw-root Conopholus and
  beech-drops Epifagus in which a lot of plastid characterization
  has been done.  Epifagus has about 70 kb of plastid DNA remaining,
  and has lost a lot of photosynthetic genes.

  Monotropa seeds are very tiny, only about 10 cells long and three
  wide constituting the embryo, with what looks like a cluster
  of smaller meristematic cells embedded.  I think that reduced
  seed size is characteristic of heterotropic plants.

  The review by Jonathan Leake,  New Phytologist, 127, 171-216 (1994)
  is good.

  Wayne
  http://morgan.botany.uga.edu/wayne.htm