curious plant behaviors

In large part due to the info on this list and the 'Net in general, I 
have a tank which is looking healthy, and is a joy to sit and watch.  In 
my watchings, I have noticed two behaviors (do plants have behaviors?  
hm...) which I am hoping someone or many someones can shed light on:

1) One of my 3 C. wendtii seems to produce 2 different types of leaves.  
most of the leaves are "normal" - coppery-green, crinkled margins, ca. 
1-2" wide, eventually 5-10" long.  However, several leaves, including 2 of 
the newest, are darker, thin, and not leaf-like at all.  These "leaves" 
actually look more like leaf-stalks which have never generated flat leaf 
tissue.  These stalks grow to about 3 inches, then stop - they do not 
rot, do not further change shape (i.e. thicken) or change color.  I'm not 
particularly worried - the plants seems quite healthy, throws odd lots 
of leaves, and actually has grown along its rhizomes into 4 visually 
distinct clusters of growth.  I am just curious about these other leaf-types.

2) I have a Crinum thaianum, which, although growth has not been 
spectacular, has divided into mother bulb plus 5 smaller young'ns.  The 
odd behavior with this plant is that as the leaves grow upward, they 
begin to rot.  The leaves just about reach the surface of my water (21") 
and then they develop dead tissue about 2/3 they way up the leaf.  If 
left undisturbed, the leaf eventually breaks off.  I usually cut off the 
leaf just below the blemish to remove rotting plant debris.  The effect 
of this is that I have at any time only 2-4 leaves actually growing up to 
the surface, on a plant which I intended to provide a full height 

If anyone has any thoughts or ideas on this, let me know.
Tank specs:  45 gal, temp. 80, pH 7.0, hardness 180 ppm (10-ish GH), 
fertilize w/ DIY CO2 and Kent FW plant, stocked moderately with tetras (20), 
clown loaches (2), pl*co (1) and kribs (5).  Set up 1 year.

Steven Petsch