Leimone Waite Master gardeners Seemingly overnight, a Redding gardener said, a rather ordinary-looking plant growing in her yard suddenly developed a bright yellow-tipped, 17-foot-tall flower stalk. The plant sure had never bloomed like that before. What in the world could it be? It's known as a spineless century plant, also called Agave attenuate, according to plant expert and Record Searchlight Master Gardener columnist Leimone Waite.