botany - What's the name of the fibrous strands that hold the seeds in a pumpkin?

If you cut open a pumpkin, the seeds are suspended inside the pumpkin by some fibrous, slimey strands. You can see them in the middle of this sliced-open pumpkin:

I'm writing a post for the Cooking.SE blog, and am trying to find out the proper botanical term. Someone suggested that might be called the endocarp, but I want to make sure and also see if there is a more specific term.

Edit

In "Morpho-Physiological Aspects of Productivity and Quality in Squash and Pumpkins (Cucurbita spp.)" §C.1, I see this:

In the central portion of the fruit, a mass of tough fibers, together with vascular strands connected to the seeds, comprise the placental tissue. The endocarp is made up of small, thin-walled cells that form a membranous tissue that adheres to seed, becoming a transparent skin on dried seeds. (emphasis added)

Am I reading correctly that the name for this part of the pumpkin is "placental tissue", and that the endocarp is just a thin layer on the seeds themselves?