Here's my research -- The leaves are 10 to 18 inches long with long, sharp, terminal spines and shorter spines along the edges.(I can attest to the sharpness as they pierced my ankle and caused quite a bit of bleeding when i was thinning out this area of the garden) The stalk can be up to 4 inches in diameter. (It certainly is 4") Members of the Amaryllis Family (wow, that's interesting....) , century plants take many years to flower, although not a century. (Ours has never flowered in the 13 years we've been in this house) Yellow flowers composed of 6 petals, bloom June through August. Flowers grow in clusters and face upward at the end of horizontal branches, appearing only near the top of the stalk This unique native plant has a tall, thin stalk from 10 to 14 feet high that grows from a thick basal rosette of gray-green leaves.
The Century Plant provided Native Americans with a source of soap, food, fiber, medicine and weapons. Agavi americana, can grow up to 40 feet high (holy crap! That's high.....I guess there will be more pictures) with much longer leaves and larger stalk. This American Century Plant is sometimes grown in southern California as an ornamental. It is used commercially in Mexico as a source to produce the liquors tequila, pulque and mescal. (yum.....tequila)
You'll notice how the plant is now above the wall of the patio.....The difference between this photo and the previous is 48 hours.