Julius' descriptions of the differences between Alocasia and Colocasia is
great, but I can add another couple of differences concerning position of
inflorescences and fruits.
Colocasia produces inflorescences in a fan running away from the petiole
from which the infl. are being produced (i.e. the back of the spate faces
the petiole from which it was produced,mand, generally, produces several
infl. per leaf. Alocasia produces inflorescences running parallel to the
leaf and generally only one or two per leaf.
In fruit Alocasia produces rather large berries carried erect, and that
ripen orange-red (like Arisaema, Arum and most Amorphophallus), and each
contain one to three (rarely more) large, round seed. The fruits are
odourless. Colocasia fruits are carried on a nodding stalk, are small,
yellow-brown, fruitily scented, and contain many, small, ellipsoid seeds.
Peter C. Boyce
Willow Wren Wharf
Hayes Road, Southall
Middlesex UB2 5HB
Tel.: (+44) (0) 20 8 573 1213 (home)
(+44) (0) 20 8 332 5207 (work)
Fax: (+44) (0) 20 8 332 5278
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----- Original Message -----
From: Julius Boos <firstname.lastname@example.org>
To: Multiple recipients of list AROID-L <email@example.com>
Sent: 30 July 2000 16:30
Subject: Re: alocasia
> -----Original Message-----
> From: Fougeroux Christophe <firstname.lastname@example.org>
> To: Multiple recipients of list AROID-L <email@example.com>
> Date: Saturday, July 29, 2000 11:58 AM
> Subject: alocasia
> Dear Christophe,
> Let me TRY to assist you with this technical one, since this is your
> plea to this list---I had hoped one of the 'big guns' out there would have
> tackled this one, but here goes--
> !) Both are closely related to each other. The most important
> between the two is microscopic, and found within the female flowers. In
> Colocasia the placentae are parietal (along the interior sides of the
> gynoecium, which is the embrionic future berry) from top to bottom, and
> many funicules ('stems'?) of the ovaries attach to the placentae along the
> interior sides of the ovary.
> In Alocasia the placenta is basal, and the sparser number of
> funicules/ovaries are attached to this placenta within the gynoecium,
> along its interior base.
> 2) Colocasia IN GENERAL has a partially peltate leaf blade, while
> Alocasia has any shaped leaf blade you want to imagine, from entirely
> peltate to sagittate, to deeply pinnatifid!!!. GENERALLY Colocasia has a
> small sterile region at the tip of the spadix, while GENERALLY Alocasia
> a longer sterile region at the apex of the spadix.
> If you have a plant you are doubtful about, the best way to get an I.D. is
> to post a picture of the plant, many will jump at the chance to I.D. it,
> at least give a good guess!
> I again urge anyone who is seriously interested in Aroids to buy the book
> 'The Genera of Araceae' by S.J. Mayo, J. Bogner and P. Boyce, there you
> find MOST of the answers to any questions you may have about this
> family of plants we SO love! It is available from the IAS on this list,
> just post a request for information, it costs about U.S. $135.00.
> Good growing,
> >I'm an Araceae which it can be an Alocasia or an Colocasia. Someone can
> tell me what's the difference between this two genus?