Hi Peter,
Sorry but I do not understand your first paragraph here. How can a cataphyll be composed of some part of the petiole? Cataphylls and petioles being entirely distinct structures, this language is confusing.
Thanks for any clarification.
Dylan
"The greatest service which can be rendered any country is to add an useful plant to its culture…" --Thomas Jefferson
On 23 October 2016 at 17:38, Peter Boyce wrote:
David,
The answer the latter part of your email first. The petiole comprises the sheathing part and the non-sheathing part. The ontogeny of a cataphyll is that it is (mostly) composed only of the sheathing part of the petiole. The remainder of the petiole, and indeed the blade, most of the time represented by a thickened tip to the cataphyll.
Returning to the first part of your email, the peduncle will have a cataphyll (and usually a prophyll) associated with it, but not attached to the peduncle. Instead the cataphyll will be part of the preceding shoot (module or article depending on who's terminology is favoured).
Indeed, the cataphyll (and prophyll) are protective.
Kind Regards
Peter
On 23 October 2016 at 10:10, DAVID LEEDY wrote:
Peter,
Thank you so much for taking the time to respond to my inquiry. As I understood it:
A cataphyll is a modified leaf which lacks a blade and in appearance corresponds to a petiole sheath. (DOES THIS MEAN THAT A PEDUNCLE DOES NOT HAVE A CATAPHYLL??) Does a cataphyll occur only in Araceae or might it be found elsewhere (name some examples). What is the function of the cataphyll ? (to provide protection to the emerging petiole and leaf??) Do some (many or most) Aroids have cataphylls?
This is really weird language "corresponds to a petiole sheath" Why not say that the cataphyll sheaths the petiole?
As I recall, from a conversation about 30 or 40 years a go, a cataphyll that falls off the plant is called a deciduous cataphyll and one that stays on is called a persistent cataphyll.
Your comments and corrections are, as always, appreciated.
My very best regards,
David Leedy
On Friday, October 21, 2016 4:21 PM, Peter Boyce wrote:
Hello David,
Taken from Flora of Thailand
cataphyll – a modified leaf which lacks a blade and in appearance corresponds to a petiole sheath; may be used to describe other leaf types whose technical names are defined by position rather than form, e.g., prophylls are usually of cataphyll shape in Araceae, compare, prophyll.
prophyll – the first leaf of a branch (or sympodial unit); in Araceae almost always a 2-keeled cataphyll, often confused with cataphyll; cataphyll refers to a particular type of morphology (reduced leaf), prophyll refers to the position of the leaf along a branch.
On 20 October 2016 at 23:14, DAVID LEEDY wrote:
I am seeking a written description of the term cataphyll, including the function it performs. Is it found only at the base of peduncles or also at the base of petioles? Examples including images of each. Is it only found in the Aroid plant family or elsewhere?
Thanks for your help.
David Leedy
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