RE: Aquatic Plants Digest V5 #444

[kyle at onebox_com]

Thanks to the people who caught my bonehead mistake on Glossostigma, I'll just pretend I wasn't a plant taxonomist when I wrote that!


 To continue the discussion:

> Mosses and Liverworts are another group of plants that don't fit into
> the groups you asked about.  Like ferns they reproduce by spores, but
> they have no vascular tissue (a major reason they stay small).

>Some do have simple vascular tissue, but most as a rule do not.

Yes, some do have simple conducting tissue but none have true 
vascular tissue.  True vascular tissue is made up of xylem and phloem.

 
>If you want a question: what is the difference between Chara and >Riccia? Why
>is one an "alga" and the other a "plant". Chara looks like a >whorled stem
>plant with internodal development, Riccia look more like algae than >this
>algae does.
>This will be fun:)

In short...SHOW ME THE EMBRYO! :)  I haven't looked up Charophyte 
reproduction in quite a while so I forget if it has a sporic
lifecycle.  The current evidence is that they all form one
big group but the mosses,liverworts and vascular plants (lets not 
forget the hornworts too...but not the hornwort most people on the
list know) do form a monophyletic group.  What I avoided writing was
the widely accepted common name for them, the land plants because it
sounds weird when we discuss aquatic plants, but that's what they are!  

The technical name for the land plants is the Embryophyta and 
they all retain the newly developing 
plant on the parent, thus an embryo (for the botanists out there
I'm avoiding the gametophyte-sporophyte explaination because 
that would take too long to do it justice).  I don't think any 
green algae do that (I'm at home so I don't have any references
 with me at the moment), so if I am correct then that is the big
 difference between "plants" and "green algae". Another major 
difference is that land plants have a waxy cuticle and green algae
don't.

For classification purposes I consider green algae and plants all 
the kingdom Plantae.  Land plants should be a subkingdom
 (Embryophyta...or whatever the proper ending to a subkingdom is!) and  Green algae would be split into several subkingdoms as well.

If you really want to drown the group in technical botanical
 discussions I propose Monocots vs. Dicots, Angiosperms vs.
 Gymnosperms, Ferns-Lycophytes-Sphenophytes, and Mosses-Liverworts-
Hornworts for endless hours of fun!  :)

-Kyle