Geophyte - an uncomfortable definition ?

Angelo Porcelli
Sun, 25 Jan 2004 01:04:10 PST
Dear all,
I was reading with calm all the messagges of the last few days (hey they are a lot, this is by far the more active forum I belong !) and some considerations, or better questions, come in mind.
The definition of geophyte could raise a very controversial debate and when a statement is made, there's always an odd plant that won't fit in it, causing problem with all those with a ' well packet mind' or professed lovers of 'cosmic order' :-) 
So, is geophyte any plant with an organ of storage underground ?
Then to start, do Clivia and Agapanthus fit in this definition? Which is thier storage organ?
Strelitzias have thickened fleshy roots (much bigger than Clivia or Agapanthus) and undeground rhizomes; are they geophytes?
How we should consider Crinum asiaticum and allies? They don't have any bulb, in the classic sense of term, and if we call the pseudostem as bulb, then bananas should be considered in the same way or not? These do have rhizomes from which new offsets emerge and can even be cut in pieces, starting new plants.
Several cycads develope an underground caudex (another word to clarify !) in the early stage of their live (means the first 30 years for some species !) and some Australian Macrozamia and South African Encephalartos grow in this way all their life and some even loose leaves and go dormant. These are true geophytes, in any way you use this word, but they are never mentioned in any catalogue of bulbs seller !
From some years there is a new fashion in the collectors of succulents. So, while they are getting tired from the well known cactus (in their miriad of forms, hybrids, subspecies different just for a longer of shorter spine! ) now they speak with enthusiasm of cauduciform (right spell?) and come keen collectors have now an Ammocharis or a Boophane in their list. I have even heard people in US growing Urginea maritima in their collection of succulents ! 
Crassulaceae family isn't considered to be a 'geophyte' family, but the native Umbilicus rupestris has a true tuber and has a dormancy. And what about Cucurbitaceae (yes, the family of pumpkins !). There are a couple of genus ( Ibervillea and Xerosyce) with tuber, which developes a season aerial vegetation and later disapperas.

Ok stop now, as at early Sunday morning brain could even not work properly... assuming it works so during the rest of the week :-)


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