Thank you Tiffany and Karen.
Do agave stems get thicker and rubbery in texture as they grow larger? The reason I ask is that this plant was started from a small division of a larger plant that had stems of that nature. I had wondered at that time if it was perhaps some type of aloe, as it seemed to me their texture were more reminiscent of that. I always thought that agave stems were very stiff and hard with quite treacherous spines. The spines on this plant were and are not sharp.
Here is a picture of the original plant; it had been donated for a plant sale at my garden club several years ago and I ended up taking it because nobody else wanted it. Subsequently I passed on the plant to someone else and just keep a small offshoot for myself; it was very slow to start growing but has finally got going since spending the summer outdoors this year. Not sure if you can tell how really thick some of the stems are from the picture. The plant was very floppy, I'm assuming from a lack of sunlight.