hi and thanks for the reply!
[...below...]

" wrote:

You probably have aphids or mealybugs, both are very common on tropical
hibiscus.

no pests i have been over them with magnifying glasses (plus some have
those yellow insect *traps* - sticky) and there are no pests...

What you are seeing is probably not sap, but insect poop.

no it is very sticky and is *only* at the leaf base

On another note, sap production is a function of staying alive, the
only thing that would affect its production is temperature.

this began during the summer (2004) (i live in zone 5 -- these are
housePlants) and it continues now (and through the winter)
(the house temp fluctuates slightly summer - winter)
thanks

Toad

sincerely
Tanya