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Re: Why does E.Tenellus belong to E. family?

On Sunday 18 August 2002 13:48, you wrote:

Just to be picky, the *genus* is Echinodorus, the family is Alismatacaea, 
which it shares with genus Sagittaria.
> I've always wondered why E.Tenellus belongs to the sword family? It looks
> unlike any other swords that I know of. Others have a blade of leaf
> attached on the petiole but tenellus looks just like a narrow blade of
> grass.(blyxa sp)

I think that its flowers and fruit place it in Echinodorus.   The root word 
echino- refers to the small spines on its burr-like fruit. The leaves that 
you are thinking of are unique to adults of the larger species.

Strap-like leaves are far from unique among the other Echinodorus.  I'm not 
up on the current species nomencature, but there are a number of small 
Echinodorus that share the same leaf type.  Moreover, I know that seed-grown 
juvenile plants of E. cordifolius have strap-like leaves and look quite a lot 
like small E. tenellus.  I suspect that juveniles of most or all other 
species have the same habit.  The US-native E. berteroi can bare several 
different leaf shapes on the same plant; strap-like, narrow-bladed or 
oval-bladed, erect or floating.

Sagittaria are very similar to Echinodorus and they follow the same pattern. 
A few small species always have strap-like leaves.  In other species the 
submersed leaves are strap-like while the emersed leaves have distinct 
petioles with arrow-shaped (sagittate) or oval leaves.  In fact, I think the 
only distinctions between Echinodorus and Sagittaria are in their flowers and 

> Moreover, tenellus propagate by runners which I do not see in other swords.
> I've never tried growing it on land. Does it send a flower stalk with
> plantlets growing on it?

I'm not sure what the correct name is for the "runner" of E. tenellus, but 
other small species have the same habit.  I suspect that the runner is the 
same structure that bares flowers in larger species.  E. tenellus grown 
emersed flowers like other Echinodorus.  I presume that the flowering stalk 
would also bare small plants.

Roger Miller