What plant is it?-its an Alocasia...or is it?

David Poole dave-poole at ilsham.demon.co.uk
Wed Oct 8 17:36:25 EST 1997


On Wed,  8 Oct 97 Sean  wrote:

>Hi David -
>
>I'm very curious about Colocasia gigantea - I can find it mentioned
>on the AROID-L group but without any description.

C. gigantea grows as an essentially tuberous rooted plant up to 2
metres overall - often somewhat less.  The leaf stems are somewhat
slender, clasping at the base, persistent, eventually forming false
'trunks'.  The blades are large, broadly sagittate-peltate to 80-100
cms long,rather bright green with a satin sheen to the upper surface
and slightly or distinctly glaucous beneath.  The leaf margins are
undulate to varying degrees.  The spathes (flowers) are white to
25cms. long with shorter, creamy or yellowish spadices, slightly
hooded, apically rounded, prominently constricted toward the base,
with no attenuation.  Flowers appear in clusters of up to 6 or even
more at any one time and are basal in origin.

[snip]
>This is the area
>at which the leaf attaches to the stem - in Jaun's photo, I recall
>that there was a slight 'web' span between the two anterior lobes,
>creating a 'peltate' attachment though the leaf was otherwise the
>same as all of these 'elephant ear' types of aroids.  
Colocasia also has this extension into the sinus, but not quite to the
same extent as some Alocasias.

[snip]
>I don't really know what the
>real distinction between Alocasia and Colocasia is - perhaps it is
>primarily in the flower structures (which we don't have).
I suspect you are right.  I'm not so familiar with the flowers of
Alocasia as you, but the differences between the two genera appear to
be at best, marginal.  I take an almost 'layman's' view by thinking of
the Odora section of Alocasia as being near tree-like with eventually
prominent, persistent, somewhat woody trunks, whereas Colocasia tends
to be distinctly more 'herbaceous', with tuberous roots below or just
above soil level.  Alocasias in general, also tend to have heavier
textured, glossier leaves than their near cousins.  Without doubt, the
large Alocasias are much more substantial plants

As it is, Juan's plant will need to put on a good deal more growth
before it can be correctly assigned.

>Anyhow - not really arguing - I just can resist trying to figure these
>things out.
I agree 100%.  The problem is that as fascinating as these giant
aroids are, their successful accommodation is very difficult over here
due to their immense proportions, requiring very large heated
structures or ball-room sized living rooms!  

David Poole



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